Jelena D. Gojgić1, Aleksandar M. Petričević1,
Mila N. Krstajić Pajić1, Vladimir D. Jović2*
1University of Belgrade, Faculty of Technology and Metallurgy, Belgrade, Serbia, 2Retired from the University of Belgrade, Institute for Multidisciplinary Research, Belgrade, Serbia
Scientific paper
ISSN 0351-9465, E-ISSN 2466-2585
https://doi.org/10.62638/ZasMat1039
Zastita Materijala 65 (1)
3 – 10 (2024)
Correct determination of the hydrogen evolution reaction parameters at Ni foam electrode modified by electrodeposited Ni-Sn alloy layer
Abstract
The example of the procedure for the correct determination of the parameters of hydrogen evolution reaction (HER), the exchange current density (jo) and relaxation time (to) for intermediate (adsorbed hydrogen, Hads) adsorption at modified porous Ni-based electrode are presented in this work. Such a procedure is applicable for the HER at all electrode materials. The value of jo was obtained from the intercept at h = 0 mV from the h vs. log (Rct-1) dependence (h – overpotential), while the value of to was obtained from the intercept at h = 0 mV from the logt vs. h dependence. It was shown that for the correct determination of jo and to, it is necessary to correct applied h for the jRs drop, by recording current density (j) for applied h and correcting it for jRs.
Keywords: HER parameters, exchange current density, relaxation time, Ni-Sn alloy, Ni foam, 30% KOH
Procedura korektnog određivanja parametara reakcije izdvajanja vodonika na elektrodi od ni pene modifikovane elektrohemijski istaloženom ni-sn legurom
Na primeru izdvajanja vodonika na Ni-Sn/Ni pena 800 elektrodi u ovom radu je prikazana procedura korektnog određivanja parametara ove reakcije, a to su: gustina struje izmene (jo) i relaksaciono vreme adsorpcije intermedijara (t) (Hads). Vrednost jo je određena iz odsečka za h = 0 mV zavisnosti h vs. log(Rct-1) (h – prenapetost), dok je vrednost to određena iz odsečka za h = 0 mV zavisnosti logt vs. h. Pokazano je da je za korektno određivanje ovih parametara neophodno korigovati gustinu struje pri svakoj zadatoj prenapetosti za vrednost omskog pada napona jRs.
Ključne reči: Reakcija izdvajanja vodonika, gustina struje izmene, relaksaciono vreme, Ni-Sn legura, Ni pena, 30 % KOH
Agha Inya Ndukwe
Federal University of Technology, Department of Materials & Metallurgical Engineering, Owerri, Imo State, Nigeria
Review paper
ISSN 0351-9465, E-ISSN 2466-2585
https://doi.org/10.62638/ZasMat1034
Zastita Materijala 65 (1)
11 – 21 (2024)
Corrosion inhibition of carbon steel by eucalyptus leaves in acidic media: An overview
Abstract
This paper concerns the overview of previous studies on the corrosion and inhibition of carbon steel that is allowed to degrade in a corrosive medium by the extract of the eucalyptus plant, with an emphasis on the extract’s adsorption behaviour. Many researchers have largely employed eucalyptus plant bark, oil, and leaf extracts to prevent the corrosion of mild steel in acidic environments under various temperature settings. According to the results, when the bark extract of the eucalyptus plant was added to HCl (5%) at a concentration of 900 ppm, the inhibitor’s maximum efficiency was 98.2 %. The leaf extract, on the other hand, had the maximum inhibitory efficacy of 93.09 % at 600 mg/L extract concentration in the H2SO4 (0.5 M) medium. The extracts’ potency was shown to diminish with increasing temperature. The mechanism for eucalyptus extract’s protection of carbon steel from corrosion in diverse corrosive situations was largely associated with the adsorption of the extract’s inhibitive components on the steel’s surface to reduce the interaction between the metal and the corrosive surroundings. The majority of the reported inhibitive behaviour of the eucalyptus extract was consistent with the Langmuir adsorption isotherm model.
Keywords: eucalyptus leaf-extract, inhibition efficiency, mild steel, Langmuir isotherm model, corrosion inhibition, carbon steel.
Inhibicija korozije ugljeničnog čelika lišćem eukaliptusa u kiseloj sredini: pregled
Izvod
Ovaj rad se bavi pregledom prethodnih studija o koroziji i inhibiciji ugljeničnog čelika kome je dozvoljeno da se razgradi u korozivnom medijumu ekstraktom biljke eukaliptusa, sa naglaskom na adsorpcionom ponašanju ekstrakta. Mnogi istraživači su uglavnom koristili koru, ulje i ekstrakte listova eukaliptusa kako bi sprečili koroziju mekog čelika u kiselim sredinama pod različitim temperaturnim uslovima. Prema rezultatima, kada je ekstrakt kore biljke eukaliptusa dodat u HCl (5%) u koncentraciji od 900 ppm, maksimalna efikasnost inhibitora iznosila je 98,2 %. Ekstrakt lista je, s druge strane, imao maksimalnu inhibitornu efikasnost od 93,09 % pri koncentraciji ekstrakta od 600 mg/L u medijumu H2SO4 (0,5 M). Pokazalo se da potencija ekstrakata opada sa povećanjem temperature. Mehanizam za zaštitu ugljeničnog čelika ekstrakta eukaliptusa od korozije u različitim korozivnim situacijama bio je u velikoj meri povezan sa adsorpcijom inhibitivnih komponenti ekstrakta na površini čelika kako bi se smanjila interakcija između metala i korozivne okoline. Većina prijavljenih inhibitivnih ponašanja ekstrakta eukaliptusa bila je u skladu sa modelom izoterme Langmuir adsorpcije.
Ključne reči: ekstrakt lista eukaliptusa, efikasnost inhibicije, meki čelik, model Langmuirove izoterme, inhibicija korozije, ugljenični čelik
Susai Rajendran1,2* , Abdulhameed Al-Hashem3, Arjunan Krishnaveni4, Little Jewelcy Arockiaraj1, Gurmeet Singh5, Caslav Lacnjevac6, Murugan Naga Jothi7, Pooviah Shanthy7
1Department of Chemistry, Corrosion Research Centre, St. Antony’s College of Arts and Sciences for Women, Dindigul-624005 (Mother Teresa Women’s University,Kodaikanal, India), 2Adjunct Professor, Centre for Nanoscience and Technology, Pondicherry University, Puducherry, India, 3Petroleum Research Centre, Kuwait Institute for Scientific Research, Kuwait, 4PG Department of Chemistry, Yadava College Madurai, Tamil Nadu, India, 5Vice Chancellor, Pondicherry University, Puducherry, India, 6Faculty of Agriculture, University of Belgrade, Serbia, 7Deparetment of Chemistry, Sri Meenakshi Government Arts College for Women (A,) Madurai, India
Scientific paper
ISSN 0351-9465, E-ISSN 2466-2585
https://doi.org/10.62638/ZasMat1040
Zastita Materijala 65 (1)
22 – 34 (2024)
Corrosion inhibition by fruit extracts -Inhibition of corrosion of mild steel in simulated concrete pore solution prepared in sea water by an aqueous extract of apple juice- A Case study
Abstract
The inhibition efficiency of an aqueous extract of apple juice in controlling corrosion of mild steel immersed in simulated concrete pore solution (SCPS) prepared in sea water, has been evaluated by weight loss method. Langmuir adsorption isotherm has been investigated. The mechanistic aspect of corrosion inhibition has been investigated by Electrochemical impedance spectra (AC impedance spectra). The protective film has been analysed by Fluorescence spectroscopy, FTIR spectroscopy and AFM. The SCPS system offers 60% inhibition efficiency to mild steel immersed in sea water. In presence of apple juice extract the inhibition efficiency increases as the concentration of the extract increases. When 10 ml of extract is added, 85% inhibition efficiency is obtained. Electrochemical impedance spectra (AC impedance spectra) reveal that a protective film is formed on the metal surface. In the presence of inhibitor system, charge transfer resistance value increases, impedance value increases, phase angle value increases whereas double layer capacitance value decreases as expected. The FTIR spectral study reveals that the protective film consists of complexes consisting of iron-active principles of the apple juice extract. AFM study reveals that when the inhibition efficiency increases the roughness of the surface decreases or in other words the smoothness of the system increases.
Keywords: corrosion inhibition, mild steel I, simulated concrete pore solution ,sea water , an aqueous extract of apple juice, electrochemical studies, FTIR, Fluorescence spectroscopy, AFM.
Inhibicija korozije voćnim ekstraktima – inhibicija korozije mekog čelika u simuliranom rastvoru pora betona pripremljenom u morskoj vodi vodenim ekstraktom soka od jabuke – studija slučaja
Izvod
Efikasnost inhibicije vodenog ekstrakta soka od jabuke u kontroli korozije mekog čelika uronjenog u rastvor simuliranih betonskih pora (SCPS) pripremljen u morskoj vodi, procenjena je metodom gubitka težine. Istražena je Lengmirova izoterma adsorpcije. Mehanički aspekt inhibicije korozije je istražen spektrima elektrohemijske impedanse (AC impedance spectra). Zaštitni film je analiziran fluorescentnom spektroskopijom, FTIR spektroskopijom i AFM. SCPS sistem nudi efikasnost inhibicije od 60% za meki čelik uronjen u morsku vodu. U prisustvu ekstrakta soka od jabuke efikasnost inhibicije se povećava kako se koncentracija ekstrakta povećava. Kada se doda 10 ml ekstrakta, postiže se 85% efikasnost inhibicije. Spektri elektrohemijske impedanse (AC impedance spectra) otkrivaju da se na površini metala formira zaštitni film. U prisustvu inhibitornog sistema, vrednost otpora prenosa naelektrisanja se povećava, vrednost impedanse raste, vrednost faznog ugla se povećava dok vrednost kapacitivnosti dvojnog sloja opada prema očekivanjima. FTIR spektralna studija otkriva da se zaštitni film sastoji od kompleksa koji se sastoje od gvožđe aktivnih supstanic ekstrakta soka od jabuke. AFM studija otkriva da kada se efikasnost inhibicije poveća, hrapavost površine se smanjuje ili drugim rečima, glatkoća sistema se povećava.
Ključne reči: inhibicija korozije, meki čelik, simulirani rastvor pora betona, morska voda, vodeni ekstrakt soka od jabuke, elektrohemijske studije, FTIR, fluorescentna spektroskopija, AFM.
Siska Prifiharni1*, Amalia Rizky Sabila2, Gadang Priyotomo1, Arini Nikitasari1, Rahayu Kusumastuti1, Siti Musabikha1, Rahma Nisa Hakim1, Yanyan Dwiyanti2, Bening Nurul Hidayah Kambuna2
1National Research and Innovation Agency, Research Center of Metallurgy, Tangerang Selatan, Indonesia, 2University of Sultan Ageng Tirtayasa, Departement of Metallurgy, Cilegon, Indonesia
Scientific paper
ISSN 0351-9465, E-ISSN 2466-2585
https://doi.org/10.62638/ZasMat1006
Zastita Materijala 65 (1)
35 – 44 (2024)
Electrochemical analysis of corrosion inhibition shallot leaf (Allium cepa) extract on mild steel in acidic medium at different immersion times
Abstract
Plant derivatives as eco-friendly corrosion inhibitors are currently greatly interested in much research. Shallot leaf (Allium cepa) was utilized in 0.1M HCl as a corrosion inhibitor of mild steel. The functional groups present in the macerated extract were subsequently identified using an FTIR test. Electrochemical tests such as tafel polarization and EIS were carried out to determine the corrosion inhibition performance of shallot leaf extract on the SS400 steel. The results of the electrochemical analysis show that shallot leaf extract can inhibit mild steel up to 94% at a concentration of 500 ppm. Furthermore, the addition of SLE reduces surface damage of mild steel, which can be seen by SEM.
Keywords: Corrosion inhibitor, plant extract, shallot leaf extract, carbon steel, immersion time
Elektrohemijska analiza inhibicije korozije ekstrakta lista shallot (Allium cepa) na mekom čeliku u kiseloj sredini pri različitim vremenima potarpanja
Izvod
Biljni derivati kao ekološki prihvatljivi inhibitori korozije su trenutno veoma zainteresantni za mnoga istraživanja. List SHALLOT (Allium cepa) je korišćen u 0,1 M HCl kao inhibitor korozije mekog čelika. Funkcionalne grupe prisutne u maceriranom ekstraktu su naknadno identifikovane korišćenjem FTIR testa. Sprovedeni su elektrohemijski testovi kao što su Tafel polarizacija i EIS da bi se odredio učinak inhibicije korozije ekstrakta lista Shallot na SS400 čeliku. Rezultati elektrohemijske analize pokazuju da ekstrakt lista Shallot može inhibirati meki čelik do 94% u koncentraciji od 500 ppm. Štaviše, dodatak SLE smanjuje površinsko oštećenje mekog čelika, što se može videti pomoću SEM.
Ključne reči: inhibitor korozije, biljni ekstrakt, ekstrakt lista ljutike, ugljenični čelik, vreme potapanja.
Snežana Marković1, Bojana Radojković2, Bore Jegdić2, Aleksandar Jovanović3, Jovica Stojanović3, Milan Trumić1, Vaso Manojlović4*
1University of Belgrade, Technical Faculty in Bor, Bor, Serbia, 2University of Belgrade, Institute for Chemistry, Technology and Metallurgy, Belgrade, Serbia, 3Institute for Technology of Nuclear and Other Mineral Raw Materials, Belgrade, Serbia, 4University of Belgrade, Faculty of Technology and Metallurgy, Belgrade, Serbia
Scientific paper
ISSN 0351-9465, E-ISSN 2466-2585
https://doi.org/10.62638/ZasMat998
Zastita Materijala 65 (1)
45 – 53 (2024)
Corrosion behavior of high- and low-chromium steel grinding balls in chloride solution
Abstract
The corrosion behaviour of three types of alloys (two low-alloy carbon steel and one stainless iron with ~15 wt.% Cr), in a solution which simulates seawater (3% NaCl solution, pH 8.1) was tested. Tested samples are used to make steel (iron) balls applied in mils for grinding copper and other ore. The corrosion tests were performed using three electrochemical methods, at room temperature in the presence of atmospheric oxygen. The linear polarization resistance (LPR) method, electrochemical impedance spectroscopy (EIS) method, and linear sweep voltammetry (LSV) method were applied. Based on measurements by LPR and EIS methods (as non-destructive methods), the value of polarization resistance (Rp) was determined and the general corrosion rate (vcorr) of the examined samples was calculated. The obtained values of the general corrosion rate can be used to calculate the service life of steel (iron) balls under exploitation conditions (seawater). The appearance of the surface after linear sweep voltammetry (LSV) measurement showed the presence of localized corrosion (pits were formed) of the tested samples, especially stainless iron, and the LSV method is not suitable for the determination of the general corrosion rate of tested samples in seawater. This form of corrosion occurs at high anodic polarizations, during performing LSV measurements.
Keywords: Low-alloy Steel, Stainless Iron, Electrochemical Corrosion, LPR, EIS, LSV, Seawater
Koroziono ponašanje čeličnih kuglica za mlevenje sa visokim i niskim sadržajem hroma u rastvoru hlorida
Izvod
Ispitivano je koroziono ponašanje tri vrste legura (dva nisko-legirana ugljenična čelika i jedan uzorak je nerđajuće gvožđe sa ~15% Cr), u rastvoru koji simulira morsku vodu (3% rastvor NaCl, pH 8,1). Ispitani uzorci se koriste za proizvodnju čeličnih kugli koje se primenjuju u mlinovima za mlevenje bakarnih i drugih ruda. Koroziona ispitivanja su izvedena primenom tri elektrohemijske metode, na sobnoj temperaturi u prisustvu atmosferskog kiseonika. Korišćene su metoda linearne polarizacione otpornosti (LPR), metoda elektrohemijske impedansne spektroskopije (EIS) i metoda linearne promene potencijala (LSV). Na osnovu merenja LPR i EIS metodama (kao nerazarajućim metodama), određena je vrednost polarizacione otpornosti (Rp), a zatim je izračunata vrednost brzine opšte korozije (vkor) ispitivanih uzoraka. Dobijene vrednosti za brzinu opšte korozije se mogu koristiti za izračunavanje veka trajanja kugli u uslovima eksploatacije (morska voda). Izgled površine ispitivanih uzoraka nakon izvođenja LSV metode pokazao je prisustvo lokalizovane korozije (formirane su jamice, pitovi) na ispitivanim uzorcima, posebno na nerđajućem gvožđu. Prema tome, LSV metoda nije pogodna za određivanje brzine opšte korozije ispitivanih čelika u morskoj vodi. Ovaj oblik korozije javlja se pri visokim anodnim polarizacijama tokom izvođenja LSV merenja.
Ključne reči: Nisko-legirani čelik, nerđajuće gvožđe, elektrohemijska korozija, LPR, EIS, LSV, morska voda
Vijayalakshmi Arumugam⃰, Sowmiya Chandrasekar
Research department of physics, Sri Vasavi college Erode,
Tamil Nadu, India
Scientific paper
ISSN 0351-9465, E-ISSN 2466-2585
https://doi.org/10.62638/ZasMat1000
Zastita Materijala 65 (1)
54 – 62 (2024)
Reinforce the surface properties of domestic garbage activated carbon by low temperature plasma accustomed in energy storage applications
Abstract
Since activated carbon is a highly porous material with a sizable internal surface area, it is simple to adsorb a wide range of substances when used in energy storage devices, sewage treatment, water purification, catalyst, food processing and other applications. This work focuses on the viability of using mixed fruit peels as a precursor for the carbonization process with physical activation to produce activated carbon. The Phase confirmation was examined using X-ray diffraction (XRD). Fourier transform infrared spectrometer (FTIR) concludes the functional groups present in mixed fruit peels activated carbon. Field emission scanning electron microscopy (FESEM) was used to analyze the morphological makeup and textural traits of the activated carbon that was produced. Energy Dispersive X-Ray Analysis (EDX) shows the elemental composition of nano powdered carbon. Raman spectroscopy confirms the presence of graphene that appears at 1580cm-1. Electrochemical Impedance Spectroscopy (EIS) and Nyquist plot in order to evaluate the conductivity performance over the frequency range of 1mHz to 10 kHz, measurements were used.
Carbon yield analysis were conducted and analyzed. Wettability of the mixed fruit peels were examined using contact angle. The Mixed Fruit peels activated carbon were subjected to low temperature plasma to increase its surface properties, The outcomes were evaluated, and the charge transfer resistance and the polarization resistance for air plasma treatment is 1.43 and 0.2 ohms. Hydrophilic nature is occurred when treated with air plasma. According to these findings, air plasma treatment of mixed fruit peel activated carbon improves its surface characteristics, making it suitable for electrode in energy storage applications.
Keywords: Mixed fruit peels, physical activation, low temperature plasma, surface modification, Nano powder
Ojačana površinska svojstva aktivnog uglja iz kućnog otpada pomoću plazme niske temperature koja se koristi u aplikacijama za skladištenje energije
Izvod
Pošto je aktivni ugalj visoko porozan materijal sa značajnom unutrašnjom površinom, lako je adsorbovati širok spektar supstanci kada se koristi u uređajima za skladištenje energije, tretmanu otpadnih voda, prečišćavanju vode, katalizatorima, preradi hrane i drugim primenama. Ovaj rad se fokusira na održivost upotrebe mešanih kora voća kao prekursora za proces karbonizacije sa fizičkom aktivacijom za proizvodnju aktivnog uglja. Fazna potvrda je ispitana korišćenjem rendgenske difrakcije (XRD). Infracrveni spektrometar sa Furijeovom transformacijom (FTIR) zaključuje funkcionalne grupe prisutne u mešanom aktivnom uglju od kore voća. Skenirajuća elektronska mikroskopija polja (FESEM) je korišćena za analizu morfološkog sastava i teksturnih osobina aktivnog uglja koji je proizveden. Energetska disperzivna rendgenska analiza (EDX) pokazuje elementarni sastav nano praškastog ugljenika. Ramanova spektroskopija potvrđuje prisustvo grafena koji se pojavljuje na 1580cm-1. Korišćena su elektrohemijska impedansna spektroskopija (EIS) i Nyquist-ovi dijagrami u cilju procene performansi provodljivosti u opsegu frekvencija od 1mHz do 10 kHz.
Sprovedena je i analizirana kolicina prinosa ugljenika. Vlaženje kore mešanog voća je ispitivano primenom kontaktnog ugla. Aktivni ugalj za mešane voćne kore je podvrgnut plazmi niske temperature da bi se povećala svojstva površine. Rezultati su procenjeni, a otpor prenosa naelektrisanja i otpor polarizacije za tretman vazdušnom plazmom je 1,43 i 0,2 oma. Hidrofilna priroda se javlja kada se tretira vazdušnom plazmom. Prema ovim nalazima, tretman vazdušnom plazmom mešanog aktivnog uglja od kore voća poboljšava njegove površinske karakteristike, čineći ga pogodnim za elektrode u aplikacijama za skladištenje energije.
Ključne reči: Mešane voćne kore, fizička aktivacija, niskotemperaturna plazma, modifikacija površine, Nano prah.
Dipsikha Bhattacharya*
Adamas University, Department of Chemistry, School of Basic and Applied Sciences, Kolkata, India
Scientific paper
ISSN 0351-9465, E-ISSN 2466-2585
https://doi.org/10.62638/ZasMat1041
Zastita Materijala 65 (1)
365 – 371 (2024)
Development of hyaluronate tethered magnetic nanoparticles for targeted anti-cancer drug delivery
Abstract
Despite the tremendous progress in understanding the molecular basis of the disease, cancer still remains one of the leading causes of deaths. Recently, advances in nanotechnology are rapidly enabling the development of novel, multifunctional materials with combined cancer specific targeting, therapeutic and diagnostic functions within a single nanocomplex (NP) that address the shortcomings of traditional disease diagnostic and therapeutic agents. Among the myriad of nanocarriers, magnetic nanoparticles (MNPs) have sparked extensive promise as novel theranostic applications as these MNPs can be directly targeted to the diseased cells with effective therapeutic efficiency. For this, these MNPs should be modified with some highly biocompatible polymers (specially polysaccharides) exhibiting the cancer targeting properties that can strongly interact with receptors expressed on the target cancer to facilitate accurate detection of the specific cancer and enhanced delivery to the target site while reducing unintended tside effects. Over the last few years, many groups have reported hyaluronic acid (HA) as the targeting agent as it directly delivers targeted MNPs to CD44 overexpressed cancer cells. In most of the cases, doxorubicin (DOX) has been used as the anticancer drug as it is largely utilized for treating a broad spectrum of cancers. In our work, we have designed a novel, intravenously injectable, CD44 receptor targeted MNP formulation, where the HA moiety of MNPs facilitate easy detection of cancer cells via receptor specific interactions, DOX can regress the cancer cells with simultaneous imaging efficacy. This theranostic MNPs led to the formation of novel nanoformulation, capable of performing concomitant detection, regression and imaging in in vitro CD44 over expressing cancer cells.
Keywords: Multifunctional, MNP, Hyaluronic acid, Doxorubicin, CD44.
Razvoj magnetnih nanočestica vezanih hijaluronatom za ciljanu isporuku lekova protiv raka
Izvod
Uprkos ogromnom napretku u razumevanju molekularne osnove bolesti, rak i dalje ostaje jedan od vodećih uzroka smrti. Nedavno, napredak u nanotehnologiji ubrzano omogućava razvoj novih, multifunkcionalnih materijala sa kombinovanim ciljanim, terapeutskim i dijagnostičkim funkcijama za rak u okviru jednog nanokompleksa (NP) koji se bavi nedostacima tradicionalnih dijagnostičkih i terapeutskih agenasa za bolesti. Među bezbroj nanonosača, magnetne nanočestice (MNP) su izazvale veliko obećanje kao nove terapeutske primene jer ovi MNP mogu biti direktno ciljani na obolele ćelije sa efikasnom terapijskom efikasnošću. Za ovo, ovi MNP-ovi bi trebalo da budu modifikovani nekim visoko biokompatibilnim polimerima (posebno polisaharidima) koji pokazuju svojstva ciljanja raka, koja mogu snažno da interaguju sa receptorima eksprimiranim na ciljnom karcinomu kako bi se olakšalo tačno otkrivanje specifičnog raka i poboljšana isporuka na ciljno mesto uz smanjenje neželjene nuspojave. Tokom poslednjih nekoliko godina, mnoge grupe su prijavile hijaluronsku kiselinu (HA) kao sredstvo za ciljanje jer direktno isporučuje ciljane MNP u ćelije raka sa prekomernom ekspresijom CD44. U većini slučajeva, doksorubicin (DOKS) je korišćen kao lek protiv raka jer se u velikoj meri koristi za lečenje širokog spektra karcinoma. U našem radu, dizajnirali smo novu, intravenozno injekcionu, CD44 receptor ciljanu MNP formulaciju, gde HA deo MNP-a, olakšava lako otkrivanje ćelija raka putem interakcija specifičnih za receptor, DOKS može regresirati ćelije raka uz istovremenu efikasnost snimanja. Ovi teranostički MNP-i doveli su do formiranja nove nanoformulacije, sposobne da sprovede istovremenu detekciju, regresiju i snimanje u in vitro CD44 preko ekspresije ćelija raka.
Ključne reči: multifunkcionalno, MNP, hijaluronska kiselina, doksorubicin, CD44.
Nkemakolam Chinedu Izuwa, Stanley Toochukwu Ekwueme, Ndubuisi Uchechukwu Okereke, Onyebuchi Ivan Nwanwe, Nnaemeka Princewill Ohia
Federal University of Technology, Department of Petroleum Engineering, Owerri (FUTO), Nigeria
Scientific paper
ISSN 0351-9465, E-ISSN 2466-2585
https://doi.org/10.62638/ZasMat1009
Zastita Materijala 65 (1)
73 – 85 (2024)
Comparative analysis of geothermal binary ORC systems: performance and environmental considerations for CO2 and water as geofluids
Abstract
This study considers the process simulation of geothermal binary Organic Rankine Cycle (ORC) systems which utilizes CO2 and water as geofluids for electricity generation. The simulation was performed using Hysys v11 software by using Peng Robinson’s fluid property package. Two dry working fluids including isopentane and n-pentane, were used. The effects of geofluid temperature and working fluid mass flowrate on power generation, as well as the maximum pressure of working fluids were evaluated. The result showed that power generation increases with higher geofluid temperature due to enhanced heat transfer. Isopentane outperformed n-pentane, attributed to its superior thermodynamic properties. CO2 showed better performance as geofluid than water highlighting its superiority, observed in the increased power generation. The unique characteristics of CO2 enable efficient heat transfer at lower temperatures, making it an environmentally friendly and effective choice. Contrarily, the use of water as a geofluid poses some implications for local ecosystems and water resources. From an environmental perspective, CO2 shows greater potential for reduced environmental impact, which aligns with the transition to cleaner energy sources. However, the economic considerations suggest a trade-off, as CO2 projects may entail higher upfront costs compared to water-based systems. Regulatory factors and economic feasibility, therefore, play a crucial role in the choice of geofluid for geothermal power generation.
Keywords: Geofluid, working fluid, ORC, renewable energy
Komparativna analiza geotermalnih binarnih orc sistema: performanse i razmatranja životne sredine za co2 i vodu kao geofluide
Izvod
Ova studija razmatra simulaciju procesa geotermalnih binarnih sistema organskog Rankinovog ciklusa (ORC) koji koriste CO2 i vodu kao geofluide za proizvodnju električne energije. Simulacija je izvedena korišćenjem softvera Hisis v11 korišćenjem Peng Robinsonovog paketa fluidnih svojstava. Korišćene su dve suve radne tečnosti uključujući izopentan i n-pentan. Ocenjeni su uticaji temperature geofluida i masenog protoka radnog fluida na proizvodnju električne energije, kao i maksimalnog pritiska radnih fluida. Rezultat je pokazao da se proizvodnja energije povećava sa višom temperaturom geofluida zbog poboljšanog prenosa toplote. Izopetan je nadmašio n-pentan, što se pripisuje njegovim superiornim termodinamičkim svojstvima. CO2 je pokazao bolje performanse kao geofluid od vode, naglašavajući njegovu superiornost, primećenu u povećanju proizvodnje energije. Jedinstvene karakteristike CO2 omogućavaju efikasan prenos toplote na nižim temperaturama, što ga čini ekološki prihvatljivim i efikasnim izborom. Nasuprot tome, upotreba vode kao geofluida predstavlja neke implikacije za lokalne ekosisteme i vodne resurse. Iz perspektive životne sredine, CO2 pokazuje veći potencijal za smanjenje uticaja na životnu sredinu, što je u skladu sa prelaskom na čistije izvore energije. Međutim, ekonomska razmatranja sugerišu kompromis, jer projekti CO2 mogu dovesti do većih početnih troškova u poređenju sa sistemima zasnovanim na vodi. Regulatorni faktori i ekonomska izvodljivost, stoga, igraju ključnu ulogu u izboru geofluida za proizvodnju geotermalne energije.
Ključne reči: Geofluid, radni fluid, ORC, obnovljiva energija
Balakrishnan Latha1*, Kaliyaperumal Kavitha1
Susai Rajendran2,3
1PG and Research Department of Chemistry, National College (Autonomous),Tiruchirappalli, Affiliated to Bharathidasan University, Tiruchirappalli, Tamil Nadu, India, 2PG Department of Chemistry,
Corrosion Research Centre, St. Antony’s College of Arts and
Sciences for Women, Dindigul, Affiliated to Mother Teresa Women’s University, Kodaikanal, Tamil Nadu, India, 3Centre for Nanoscience
and Technology, Pondicherry University, Puducherry, India
Scientific paper
ISSN 0351-9465, E-ISSN 2466-2585
https://doi.org/10.62638/ZasMat1005
Zastita Materijala 65 (1)
86 – 96 (2024)
Inhibition of corrosion of mild steel in simulated oil well water by aqueous extract of Hibiscus rosa-sinensis flower
Abstract
An aqueous extract of Hibiscus rosa-sinensis flower (HRF) has been used as corrosion inhibitor in controlling the corrosion of mild steel in simulated oil well water (SOWW). Weight loss method reveals that 10 % v/v of the extract offers 82 % inhibition efficiency (IE) to mild steel (MS) immersed SOWW. The mechanistic aspects of corrosion inhibitive effect have been investigated by polarization study and AC impedance spectra. Polarization study reveals that the mixed type of inhibitor in the presence of inhibitor system. The corrosion inhibition effect is confirmed by the increase in the linear polarization resistance value and decrease in the corrosion current value. The protective layer is formed on the metal surface is confirmed by the AC impedance spectra. This is confirmed by the fact that there is increase in charge transfer resistance value and decrease in the double layer capacitance value. The adsorption of inhibitor molecule obey Langmuir adsorption isotherm. The protective coating is characterized by FTIR spectroscopy. It confirms that the inhibitor has coordinated with ferrous ion the metal surface through the active principle component of β-sitosterol, quercetin and kaempferol-3-xylosylglucoside. The surface morphology has been investigated by scanning electron microscopy (SEM). Hence, aqueous extract of Hibiscus rosa-sinensis flower with simulated oil well water good corrosive inhibitive effect on pipeline made of mild steel.
Keywords: Hibiscus rosa-sinensis, simulated oil well water, mild steel, corrosion inhibition, surface morphology, SEM
Inhibicija korozije mekog čelika u simuliranoj vodi iz bunara vodenim ekstraktom cveta Hibiscus rosa-sinensis
Izvod
Vodeni ekstrakt cveta Hibiscus rosa-sinensis (HRF) korišćen je kao inhibitor korozije u kontroli korozije mekog čelika u simuliranoj vodi iz bunara (SOWW). Metoda gubitka težine otkriva da 10% v/v ekstrakta nudi 82% efikasnost inhibicije (IE) za SOWW uronjen u meki čelik (MS). Mehanistički aspekti inhibicije korozije su istraženi proučavanjem polarizacije i spektra impedanse naizmenične struje. Studija polarizacije otkriva da je mešoviti tip inhibitora u prisustvu inhibitornog sistema. Efekat inhibicije korozije je potvrđen povećanjem vrednosti otpora linearne polarizacije i smanjenjem vrednosti struje korozije. Zaštitni sloj koji se formira na površini metala potvrđuju spektri impedanse naizmenične struje. Ovo potvrđuje činjenica da dolazi do povećanja vrednosti otpora prenosa naelektrisanja i smanjenja vrednosti kapacitivnosti dvostrukog sloja. Adsorpcija molekula inhibitora je podređena Langmuir-ovoj adsorpcionoj izotermi. Zaštitni premaz karakteriše FTIR spektroskopija. To potvrđuje da je inhibitor koordinirao sa jonima gvožđa na površini metala preko aktivne komponente b-sitosterola, kvercetina i kempferola-3-ksilozilglukozida. Morfologija površine je ispitana skenirajućim elektronskim mikroskopom (SEM). Dakle, vodeni ekstrakt cveta Hibiscus rosa-sinensis sa simuliranom vodom iz bunara ima dobar korozivni inhibitivni efekat na cevovode od mekog čelika.
Ključne reči: Hibiscus rosa-sinensis, simulirana naftna bušotina, meki čelik, inhibicija korozije, morfologija površine, SEM.
Yassine El Guerri1*, Bendaoud Mebarek2, Mourad Keddam3
1Research Laboratory of Industrial Technologies, University of Tiaret, Zaâroura, Tiaret, Algeria, 2Laboratoire de Recherche en Intelligence Artificielle et Systèmes, University of Tiaret, Zaâroura, Tiaret, Algeria
3Laboratoire de Technologie des Matériaux, Faculté de Génie Mécanique et Génie des Procédés, USTHB, El-Alia, Bab-Ezzouar, Alger, Algérie
Scientific paper
ISSN 0351-9465, E-ISSN 2466-2585
https://doi.org/10.62638/ZasMat1016
Zastita Materijala 65 (1)
97 – 109 (2024)
Confrontation of linear versus nonlinear approach in Fe2B boride layer thickness predictions
Abstract
Kinetic studies of boride layers focus on trying to accurately predict their thicknesses according to some variables using different approaches. In this paper, an approach that is reliant on a multilinear regression is investigated. In doing so, with an engineering perspective, temperature and time are used as the sole variables in predicting a boride layer thickness u. The approach uses experimental data from a boriding process performed on iron substrates of the XC38 steel. A comparison between the proposed linear model and a nonlinear one is seen afterward to scrutinize the results. That nonlinear approach is known as the diffusion model and is based on Fick’s second law, where it uses more variables than the linear approach to estimate its predictions. Ultimately, the comparison elucidated that the use of a linear regression-based model can be an accurate engineering tool to identify boride layer thicknesses, but without interpolating the results outside the scope of the studied interval.
Keywords: Multilinear regression / Linear regression / Boriding / Boride layer / Boron.
Poređenje linearnog i nelinearnog pristupa za predviđanje debljina fe2b boridnih slojeva
Izvod
Kinetička ispitivanja boridnih slojeva su usmerena na pokušaje tačnog predviđanja debljine tih slojeva primenom nekih promenljivih uz korišćenje različitih pristupa. U ovom radu su primenjeni pristupi koji se zasnivaju na multilinearnoj regresiji. Pri tome, temperatura T i vreme t su jedine promenljive koje su korišćene u predviđanju debljine sloja borida u, što je značajno sa inženjerske tačke gledišta. Navedeni pristupi koriste eksperimentalne podatke iz procesa boriranja koji je izveden na uzorcima od čelika XC38. Urađeno je poređenje linearnog i nelinearnog modela da bi se odredila valjanost rezultata predviđanja. Nelinearni pristup je poznat kao model difuzije i zasnovan je na drugom Fikovom zakonu. Taj pristup koristi više promenljivih od linearnog pristupa za procenu debljine boriranog sloja. Kao zaključak, izvršeno poređenje je pokazalo da model zasnovanog na linearnoj regresiji može biti pouzdan inženjerski alat za određivanje debljine boridnih slojeva, bez ekstrapolacije rezultata izvan proučavanog opsega.
Ključne riječi: Multilinearna regresija / Linearna regresija / boronizacija / Boridni sloj / Bor
Annamalai Selvam1*, Santiagu John Mary1, Asirvatham Ajila1,Devadoss Delinta1, Vijayagopal Sribharathy2, Senthamarai Kannan Muthukumaran3
1Department of Chemistry, Loyola Institute of Frontier Energy (LIFE), Loyola College, Chennai-600 034, Tamil Nadu, India, 2Department of Chemistry, Anna Adhars College for Women, Chennai-600 040, Tamil Nadu, India, 3Department of Chemistry, Ramakrishna Mission Vivekananda College, Chennai-600 004, Tamil Nadu, India
Scientific paper
ISSN 0351-9465, E-ISSN 2466-2585
https://doi.org/10.62638/ZasMat1004
Zastita Materijala 65 (1)
110 – 125 (2024)
Electrochemical activities of Ni-Ti alloy in artificial blood plasma with Trigonella foenum graecum seeds
Abstract
An investigation of the electrochemical behaviour of Ni-Ti alloy when exposed to artificial blood plasma (ABP) in the presence of 0.1 and 0.5 ppm of Trigonella foenum graecum (TFG) seeds for 1, 10, 20, and 30 days. Studies on AC impedance and polarisation have shown that a protective coating forms on the metal surface while inhibiting corrosion. The protective film has formed on the Ni-Ti implant alloy surface, the linear polarization resistance increased (LPR), and the corrosion current value (Icorr) decreased. The charge transfer resistant value (Rct) and impedance value increase and the double-layer capacitance value decrease.The protective layers morphology and the elemental composition were analyzed by SEM/EDAX.The property of the protective film on the Ni-Ti alloy has been examined by atomic force microscope. The X-ray diffraction analysis has confirmed the nature of the apatite. The corrosion inhibition efficiency of Ni-Ti alloy in ABP in the presence of TFG seeds at various concentrations for different times was improved and protected.
Keywords:Nickel-titanium, AFM, protective film, Nyquist plots, Bode plots
Elektrohemijske aktivnosti ni-ti legure u veštačkoj krvnoj plazmi sa semenom trigonella Foenum graecum
Izvod
Istraživano je elektrohemijsko ponašanje legure Ni-Ti kada je izložena veštačkoj krvnoj plazmi (ABP) u prisustvu 0,1 i 0,5 ppm semena Trigonella foenum graecum (TFG) tokom 1, 10, 20 i 30 dana. Studije o impedansi i polarizaciji naizmenične struje su pokazale da se zaštitni premaz formira na površini metala dok sprečava koroziju. Zaštitni film je formiran na površini legure Ni-Ti implantata, povećan je otpor linearne polarizacije (LPR), a vrednost struje korozije (Icorr) je smanjena. Vrednost otpornosti na prenos naelektrisanja (Rct) i vrednost impedanse se povećavaju, a vrednost kapacitivnosti dvoslojnog sloja se smanjuje. Morfologija zaštitnih slojeva i elementarni sastav analizirani su pomoću SEM/EDAX. Svojstvo zaštitnog filma na leguri Ni-Ti ispitano je atomskim mikroskopom. Analiza difrakcije rendgenskih zraka je potvrdila prirodu apatita.Efikasnost inhibicije korozije legure Ni-Ti u ABP u prisustvu TFG semena u različitim koncentracijama za različito vreme je poboljšana i zaštićena.
Ključne reči: Nikl-titanijum, AFM, zaštitni film, Nyquist dijagrami, Bodeovi dijagrami
Avani Kumar Upadhyay1,2, Manjeet Singh Goyat3, 4,*
1Department of Mechanical Engineering, School of Engineering, University of Petroleum & Energy Studies, Dehradun, Uttarakhand, India, 2CAD Department, Tendemloop Technologies Pvt. LTd., Bangalore, Karnataka, India, 3Department of Applied Science, School of Engineering, University of Petroleum & Energy Studies, Dehradun, Uttarakhand, India, 4Smart Materials, Mads Clausen Institute, University of Southern Denmark, Sønderborg, Denmark
Scientific paper
ISSN 0351-9465, E-ISSN 2466-2585
https://doi.org/10.62638/ZasMat1038
Zastita Materijala 65 (1)
126 – 142 (2024)
A review on improved physical and thermal properties of oxide nanoparticles reinforced epoxy composites
Abstract
Epoxy resins are well-known because of their desirable thermal and mechanical characteristics in a variety of fields, including the automotive, construction, and aerospace sectors. However, the inherent brittle nature of highly cross-linked epoxy resins generally leads to weakness in resisting the formation of cracks and their movement. The brittleness of the epoxy resins is one of the major obstacles inhibiting its use at a wider scale. Therefore, many researchers focused on reinforcement of epoxy resins by different types of nanostructures including carbon nanotubes (CNTs), organic/inorganic nanofillers to provide higher strength, without diminishing other essential thermo-physical characteristics of the nanocomposites. Most of the review articles focused on the CNT-reinforced epoxy composites and very limited review articles are available that focus on the oxide nanofiller reinforced epoxy composites. In this review article, epoxy nanocomposites reinforced with alumina (Al2O3), titania (TiO2), silica (SiO2), and zirconia (ZrO2) nanoparticles have been investigated. The influence of the oxide nanoparticles in modifying the physical and thermal properties of the epoxy nanocomposites has been presented, compared, and critically analysed to optimize the performance of epoxy nanocomposites.
Keywords: Oxide nanofiller; glass transition temperature; physical properties; thermal properties; thermal degradation
Pregled poboljšanih fizičkih i termičkih svojstava epoksidnih kompozita ojačanih nanočesticama oksida
Izvod
Epoksidne smole su dobro poznate zbog svojih poželjnih termičkih i mehaničkih karakteristika u raznim oblastima, uključujući automobilsku, građevinsku i avio-industriju. Međutim, inherentna krhka priroda visoko umreženih epoksidnih smola generalno dovodi do slabosti u otpornosti na stvaranje pukotina i njihovo kretanje. Krhkost epoksidnih smola je jedna od glavnih prepreka koja sprečava njihovu upotrebu u širem obimu. Zbog toga su se mnogi istraživači fokusirali na ojačavanje epoksidnih smola različitim tipovima nanostruktura uključujući ugljenične nanocevi (CNT), organska/neorganska nanopunila da bi se obezbedila veća čvrstoća, bez umanjivanja drugih bitnih termo-fizičkih karakteristika nanokompozita. Većina članaka za pregled fokusiranih na epoksidne kompozite ojačane CNT-om, a dostupni su vrlo ograničeni članci za pregled koji se fokusiraju na epoksidne kompozite ojačane oksidnim nanopunilima. U ovom preglednom članku istraženi su epoksidni nanokompoziti ojačani nanočesticama glinice (Al2O3), titanija (TiO2), silicijum dioksida (SiO2) i cirkonijum (ZrO2). Uticaj nanočestica oksida u modifikaciji fizičkih i termičkih osobina epoksidnih nanokompozita je predstavljen, upoređen i kritički analiziran u cilju optimizacije performansi epoksidnih nanokompozita.
Ključne reči: oksidni nanopunjač; temperatura prelaska stakla; fizička svojstva; termička svojstva; termička degradacija
Aryan Boora, Bhavna Rohilla, Priya Malik, Supriya
Sehrawat, Sushma Kumari, Anisha Sharma, Kirti Dahiya, Surender Duhan*
Advanced Sensors Lab, Department of Physics, Deenbandhu Chhotu Ram University of Science and Technology, Murthal, Haryana,India
Scientific paper
ISSN 0351-9465, E-ISSN 2466-2585
https://doi.org/10.62638/ZasMat1011
Zastita Materijala 65 (1)
143 – 150 (2024)
Impact of annealing on structural and optical properties of sol-gel derived samarium silica nanocomposites
Abstract
The pursuit of finely tuned material properties has driven the exploration of annealing strategies in the context of Samarium Silica Nanocomposites (Sm-SiO2 NCs) synthesized through the sol-gel route. This study unveils novel insights into the influence of optimized annealing protocols on the structural and functional evolution of these advanced nanocomposites. Through meticulous experimentation, we establish that controlled temperature annealing plays a pivotal role in tailoring the microstructure and properties of Sm-SiO2 NCs. The judicious manipulation of annealing parameters, including temperature duration, and atmosphere, orchestrates distinct transformations in the composite architecture. Field emission microscopy and structural analysis reveal that precise annealing promotes the consolidation of nanoscale domains, leading to improved crystallinity and enhanced connectivity between samarium species and the silica matrix. Moreover, the annealing-induced modifications extend beyond structural aspects to influence functional properties, an increase in crystallite size was observed from 15 nm to 43 nm as an effect of annealing. Our findings illustrate a remarkable enhancement in luminescence intensity as a consequence of optimized annealing, showcasing the potential for tailored photonic applications. These revelations are supported by a comprehensive suite of analytical techniques, including X-ray diffraction, Fourier transform infra red,\Field emission with Energy dispersive x-ray and photoluminescence spectroscopy. The synthesis-annealing synergy not only advances our fundamental understanding of nanocomposite evolution but also furnishes a pathway towards designing multifunctional materials with precision-engineered attributes.
Keywords: Nanocomposites, Sol-Gel Route, annealing strategies, microstructural evolution, functional enhancements
Uticaj žarenja na strukturna i optička svojstva nanokompozita od samarijum silicijum dioksida dobijenih sol-gelom
Izvod
Potraga za fino podešenim svojstvima materijala dovela je do istraživanja strategija žarenja u kontekstu nanokompozita samarijum silicijum dioksida (Sm-SiO2 NCs) sintetizovanih putem sol-gel puta. Ova studija otkriva nove vidike u uticaj optimizovanih protokola žarenja na strukturnu i funkcionalnu evoluciju ovih naprednih nanokompozita. Kroz pedantno eksperimentisanje, ustanovljeno je da žarenje na kontrolisanoj temperaturi igra ključnu ulogu u prilagođavanju mikrostrukture i svojstava Sm-SiO2 NCs. Razumna manipulacija parametrima žarenja, uključujući trajanje temperature i atmosferu, orkestrira različite transformacije u kompozitnoj arhitekturi. Emisiona mikroskopija i strukturna analiza otkrivaju da precizno žarenje promoviše konsolidaciju domena nanorazmera, što dovodi do poboljšane kristalnosti i poboljšane povezanosti između vrsta samarijuma i matriksa silicijum dioksida. Štaviše, modifikacije izazvane žarenjem se protežu izvan strukturnih aspekata kako bi uticale na funkcionalna svojstva, uočeno je povećanje veličine kristalita sa 15nm na 43nm kao efekat žarenja. Naši nalazi ilustruju značajno poboljšanje intenziteta luminiscencije kao posledicu optimizovanog žarenja, pokazujući potencijal za prilagođene fotonske aplikacije. Ova otkrića su podržana sveobuhvatnim paketom analitičkih tehnika, uključujući difrakciju rendgenskih zraka, infracrvenu Furijeovu transformaciju, emisiju polja sa energetski disperzivnom rendgenskom spektroskopijom i fotoluminiscentnom spektroskopijom. Sinergija sinteze i žarenja ne samo da unapređuje naše fundamentalno razumevanje evolucije nanokompozita, već takođe pruža put ka dizajniranju multifunkcionalnih materijala sa precizno projektovanim atributima.
Ključne reči: nanokompoziti, sol-gel ruta, strategije žarenja, mikrostrukturna evolucija, funkcionalna poboljšanja
Yashna Anthony*, Veena Ragupathi
Centre of Clean Energy and Nanoconvergence (CENCON), Department of Chemistry, Hindustan Institute of Technology and Science, Padur, Chennai, India
Scientific paper
ISSN 0351-9465, E-ISSN 2466-2585
https://doi.org/10.62638/ZasMat1002
Zastita Materijala 65 (1)
151 – 157 (2024)
Superior electrochemical performance of SnSe-PPy nanocomposites for supercapacitor application
Abstract
Recently, Metal chalcogenides have received considerable interest in the field of energy storage devices. In this work, tin selenide-polypyrrole (SnSe-PPy) nanocomposite has been synthesized by hydrothermal method and its supercapacitive behavior is investigated. The synthesized SnSe-PPy nanocomposite is analysed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and electrochemical characterisation. XRD confirms the existence of orthorhombic SnSe, and the FTIR result reveals the presence of polypyrrole. The supercapacitive behavior of SnSe-PPy nanocomposite is studied by cyclic voltammetry and galvanostatic charge-discharge studies. SnSe-PPy nanocomposite delivers the specific capacitance of 223 F g-1 at 10 mV sec -1. The addition of polypyrrole increases the conductivity of the material and improves its supercapacitive behavior.
Keywords: Tin selenide, polypyrrole, supercapacitor, specific capacity, cycle life
Superiorne elektrohemijske performanse snse-ppy nanokompozita za primenu u superkondenzatorima
Izvod
Nedavno su metalni halkogenidi dobili značajno interesovanje u oblasti uređaja za skladištenje energije. U ovom radu hidrotermalnom metodom je sintetizovan nanokompozit kalaj selenid-polipirol (SnSe-PPi) i ispitano je njegovo superkapacitivno ponašanje. Sintetizovani SnSe-PPi nanokompozit je analiziran rendgenskom difrakcijom (XRD), infracrvenom spektroskopijom Furijeove transformacije (FTIR), skenirajućom elektronskom mikroskopom (SEM) i elektrohemijskom karakterizacijom. XRD potvrđuje postojanje ortorombičnog SnSe, a FTIR rezultat otkriva prisustvo polipirola. Superkapacitivno ponašanje SnSe-PPi nanokompozita je proučavano cikličnom voltametrijom i studijama galvanostatskog pražnjenja. SnSe-PPi nanokompozit isporučuje specifičan kapacitet od 223 F g-1 pri 10 mV sec-1. Dodatak polipirola povećava provodljivost materijala i poboljšava njegovo superkapacitivno ponašanje.
Ključne reči: Kalaj selenid, polipirol, superkondenzator, specifični kapacitet, životni vek.
Vaishali Bhavsar1,2*, Deepti Tripathi2
1Applied Sciences and Humanities Department SAL College of Engineering, SAL Education, Gujarat Technological University, Ahmedabad, Gujarat, India, 2Department of Physics, School of Sciences, Gujarat University, Ahmedabad, Gujarat, India
Scientific paper
ISSN 0351-9465, E-ISSN 2466-2585
https://doi.org/10.62638/ZasMat1001
Zastita Materijala 65 (1)
158 – 168 (2024)
Tuning low frequency dielectric properties of flexible ternary polymer blend film reinforced with bio- ionic liquid for the application in green electronics
Abstract
Biofriendly conducting polymeric blends and composites exhibiting high dielectric constant and dielectric loss are promising for applications as sensors, actuators, microwave absorbing materials, fuel cells and biomedical applications. A great deal of work is reported on using fillers such as conductive nanomaterials, bio ceramics, carbon nanotubes, graphene etc in blends of Polyvinylchloride, Polyvinylpyrrolidone, Polymethylmethacrylate, Polyvinyl alcohol with conducting polymer Polypyrrole, Polyaniline for enhancing their conductivities, tailoring dielectric and electrical, thermal and surface properties of such polymeric materials. However, appropriate dispersion of such fillers in polymeric matrices remains technically challenging. In this regard, bio-ionic liquids have emerged as a novel class of materials and their combination with specific polymer blends opens the possibility to develop smart novel materials with different morphologies. Present work aims to explore the low frequency dielectric properties exhibited by free standing, flexible, biofriendly/biodegradable ternary polymer blend film of Polyvinylchloride-Polyvinylpyrrolidone-Polypyrrole reinforced with choline acetate. The detailed analysis of low frequency dielectric properties authenticates that addition of choline acetate result in modifying the dielectric properties of ternary polymer blend film.. The harmlessness of these films was confirmed from disk diffusion test indicating their benign nature towards (Escherichia coli) (CFT073) and (Bacillus subtilis). Therefore, the developed films can potentially be used for various scale multifunctional dielectric and electrical applications working in close contact with living matter, green electronics and various health monitoring systems.
Keywords: Bio ionic liquid, choline acetate, polyvinylchloride, polyvinylpyrrolidone, polypyrrol
Podešavanje niskofrekventnih dielektričnih svojstava fleksibilnog ternarnog filma mešavine polimera ojačanog biojonskom tečnošću za primenu u zelenoj elektronici
Izvod
Bioprijateljske polimerne mešavine i kompoziti koji pokazuju visoku dielektričnu konstantu i dielektrične gubitke obećavaju za primene kao senzori, materijali koji apsorbuju mikrotalase, gorivne ćelije i biomedicinske aplikacije. Izveštava se o korišćenju punila kao što su provodljivi nanomaterijali, biokeramika, ugljenične nanocevi, grafen itd. u mešavinama polivinilhlorida, polivinilpirolidona, polimetilmetakrilata, polivinil alkohola sa provodljivim polimerom polipirol polianilin za poboljšanje njihove tanilo-električne provodljivosti, dielektrične provodljivosti, i svojstva površine takvih polimernih materijala. Međutim, odgovarajuća disperzija takvih punila u polimernim matricama ostaje tehnički izazov. U tom smislu, bio-jonske tečnosti su se pojavile kao nova klasa materijala i njihova kombinacija sa specifičnim mešavinama polimera otvara mogućnost za razvoj pametnih novih materijala sa različitim morfologijama. Ovaj rad ima za cilj da istraži niskofrekventne dielektrične osobine koje pokazuje slobodno stojeći, fleksibilni, bioprijateljski/biorazgradivi ternarni polimerni film mešavine polivinilhlorid-polivinilpirolidon-polipirol ojačan holin acetatom. Detaljna analiza niskofrekventnih dielektričnih svojstava potvrđuje da dodavanje holin acetata rezultira modifikacijom dielektričnih svojstava ternarnog filma mešavine polimera. Bezopasnost ovih filmova potvrđena je testom difuzije diska koji ukazuje na njihovu benignu prirodu prema (Escherichia coli) (CFT073) i (Bacillus subtilis). Stoga se razvijeni filmovi potencijalno mogu koristiti za različite multifunkcionalne dielektrične i električne aplikacije koje rade u bliskom kontaktu sa živom materijom, zelenom elektronikom i raznim sistemima za praćenje zdravlja.
Ključne reči: Biojonska tečnost, holin acetat, polivinilhlorid, polivinilpirolidon, polipirol
Shree H.K. Ranjin, Nidhi Pathak, Charu Lata Dube*
School of Nano Sciences, Central University Gujarat, Gandhinagar, Sector, India
Scientific paper
ISSN 0351-9465, E-ISSN 2466-2585
https://doi.org/10.62638/ZasMat1037
Zastita Materijala 65 (1)
169 – 175 (2024)
Photocatalytic degradation of textile dye with titanium (IV) doped tungsten oxide nanoparticles
Abstract
Water pollution from textile industries is a major concern with respect to the availability of clean drinking water. The removal of textile (organic) dyes through photocatalytic degradation with pure WO3 and titanium (IV) doped tungsten oxide [Ti (IV)-WO3] nanospheres were studied under visible light. The WO3 and Ti (IV)-WO3 nanospheres were synthesized via microwave-assisted method at microwave power of 160 W for the duration of 20 mins. The as synthesised WO3 and Ti (IV)-WO3 nanospheres were characterized for their structural, microstructural, and spectroscopic properties by using powder X-ray diffraction (XRD), UV–Visible (UV-Vis) spectroscopy, Fourier-transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and High-resolution transmission electron microscopy (HR-TEM). The X-ray diffractograms confirmed the formation of highly pure WO3 and Ti (IV)-WO3 nanospheres. The average crystallite size of WO3 and Ti (IV)-WO3 nanospheres were calculated as 53.37 nm and 35.24 nm respectively using Debye Scherrer equation. The bandgap of Ti (IV)-WO3 was found to be decreased to 2.5 eV from 3.2 eV (WO3) respectively. It can be deduced that Ti (IV)-WO3 can be utilized as efficient visible light (λ>420 nm) driven photocatalyst as the bandgap was < 3 eV. The agglomerated spherical nanoparticles were seen for WO3 and Ti (IV)-WO3 in the HR-TEM images. The photocatalytic activity of textile dye was analyzed by UV-Vis spectrophotometer under visible light. The photocatalytic organic dye degradation was investigated. The enhanced photocatalytic activity of titanium (IV) doped tungsten oxide (10 wt%) was observed to be ~100% in 100 mins. This makes titanium (IV) doped tungsten oxide nanospheres, a potential nanomaterial for water purification.
Keywords: Photocatalytic degradation, organic dyes, microwave assisted method, photocatalytic activity
Fotokatalitička degradacija tekstilne boje sa nanočesticama volfram oksida dopovanim titanijumom (iv)
Izvod
Zagađenje vode iz tekstilne industrije predstavlja veliku zabrinutost u pogledu dostupnosti čiste vode za piće. Uklanjanje tekstilnih (organskih) boja fotokatalitičkom degradacijom sa čistim VO3 i titanijumom (IV) dopiranim volfram oksidom [Ti (IV)-VO3] nanosferama je proučavano pod vidljivom svetlošću. Nanosfere VO3 i Ti (IV)-VO3 su sintetizovane metodom uz pomoć mikrotalasa pri mikrotalasnoj snazi od 160V u trajanju od 20 minuta. Sintetizovane nanosfere VO3 i Ti (IV)-VO3 su okarakterisane po svojim strukturnim, mikrostrukturnim i spektroskopskim osobinama korišćenjem difrakcije rendgenskih zraka na prahu (XRD), UV-Visible (UV-Vis) spektroskopije, Fourier-transform infracrvene spektroskopije (FTIR), skenirajuća elektronska mikroskopija (SEM) i transmisiona elektronska mikroskopija visoke rezolucije (HR-TEM). Rendgenski difraktogrami potvrdili su formiranje visoko čistih nanosfera VO3 i Ti (IV)-VO3. Prosečna veličina kristalita VO3 i Ti (IV)-VO3 nanosfera je izračunata kao 53,37 nm i 35,24 nm respektivno korišćenjem formule Debie Scherrer. Utvrđeno je da je pojasni razmak Ti (IV)-VO3 smanjen na 2,5 eV sa 3,2 eV (VO3) respektivno. Može se zaključiti da se Ti (IV)-VO3 može koristiti kao efikasan fotokatalizator koji pokreće vidljiva svetlost (l>420 nm), pošto je pojas bio < 3eV. Aglomerirane sferične nanočestice su viđene za VO3 i Ti (IV)-VO3 na HR-TEM slikama. Fotokatalitička aktivnost tekstilne boje je analizirana UV-Vis spektrofotometrom pod vidljivom svetlošću. Istražena je fotokatalitička organska degradacija boje. Uočeno je da je povećana fotokatalitička aktivnost volfram oksida dopiranog titanijumom (IV) (10 tež.%) ~100% za 100 minuta. Ovo čini nanosfere volfram oksida dopirane titanijumom (IV), potencijalnim nanomaterijalom za prečišćavanje vode.
Ključne reči: fotokatalitička degradacija, organske boje, mikrotalasna metoda, fotokatalitička aktivnost