Utjecaj elektrolita na rezultate elektrokemijskih ispitivanja

undergraduate thesis

• Title (english): The influence of electrolyte on the results of electrochemical measurements
• Author: Ivana Perković
• Mentor: Helena Otmačić Ćurković (mentor)
• Committee member: Helena Otmačić Ćurković (predsjednik povjerenstva)
• Committee member: Ljerka Kratofil Krehula (član povjerenstva)
• Committee member: Marko Viskić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2023-09-11, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Chemistry

Abstract

U ovome radu istraživan je utjecaj izbora elektrolita na rezultate dobivene elektrokemijskim ispitivanjima, preciznije elektrokemijskom impedancijskom spektroskopijom, te polarizacijskim mjerenjima koja se baziraju na istosmjernoj struji. Koristile su se tri vrste elektrolita: jedan tekući – umjetna kiša, te dva hidrogel elektrolita – jedan na bazi agara i drugi na bazi poli(vinilalkohola). Ispitivanja s tekućim elektrolitom provođena su u klasičnoj elektrokemijskoj ćeliji s troelektrodnim sustavom – radnom elektrodom od ispitivanog materijala, referentnom zasićenom kalomel elektrodom (ZKE) i grafitnom protuelektrodom. Ispitivanja s hidrogel elektrolitima provođena su u elektrokemijskim ćelijama, gdje su kao referentna elektroda i protuelektroda korištene žice od nehrđajućeg čelika AISI 316L. Ispitivano je pet vrsta radnih elektroda – bakar, bronca, ugljični čelik, nitratna (zelena) patina, te sulfidna (crna) patina. Utvrđeno je da su rezultati dobiveni korištenjem agar i poli(vinil-alkohol) hidrogelova međusobno sličniji nego oni dobiveni korištenjem tekućeg elektrolita, iako sva tri elektrolita daju približne rezultate. Također se zaključuje da je otpor elektrolita uglavnom najvećeg iznosa prilikom korištenja tekućeg elektrolita, a najveći otpori prijenosu naboja i otpori oksida uglavnom se javljaju prilikom korištenja agar elektrolita. Najveći polarizacijski otpori dobivaju se također korištenjem agar elektrolita, a najvećih su iznosa na patinama kao radnim elektrodama. Najveći polarizacijski otpori, u sva tri elektrolita, javljaju se na nitratnoj (zelenoj) patini, a najniži na ugljičnom čeliku.

Abstract (english)

This paper investigated the impact of electrolyte on the results obtained by electrochemical tests, more precisely by electrochemical impedance spectroscopy and polarization measurements that are based on direct current. Three types of electrolytes were used: one liquid – artificial rain, and two hydrogel electrolytes – one based on agar and the other based on poly(vinyl alcohol). Tests with liquid electrolyte were performed in a classical electrochemical cell with a three-electrode system – working electrode made of test material, a reference saturated calomel electrode (SCE) and a graphite counter electrode. Tests with hydrogel electrolytes were performed in electrochemical cells, with the reference electrode and counter-electrode AISI 316L stainless steel wires. Five types of working electrodes – copper, bronze, carbon steel, nitrate ( green ) patina, and sulfide ( black) patina were tested. The results obtained using agar and poly(vinylalcohol) hydrogels were found to be more similar than those obtained using liquid electrolytes, although all three electrolytes give comparable results. It is also concluded that electrolyte resistance is generally the highest when using a liquid electrolyte, while the greatest resistances to charge transfer and oxide resistance generally occur when using agar electrolytes. The greatest polarization resistances are also obtained by using agar electrolytes, and the largest are observed on patinas as working electrodes. The highest polarization resistances, in all three electrolytes, occur on nitrate (green) patina, and the lowest on carbon steel.

• Keywords: elektrolit; hidrogel; elektrokemijska impedancijska spektroskopija; linearna polarizacija; elektrokemijska ćelija
• Keywords (english): electrolyte; hydrogel; electrochemical impedance spectroscopy; linear polarization; electrochemical cell
• Language: croatian
• URN:NBN: urn:nbn:hr:149:358793
• Project: Number: IP-2019-04-5030; Title: Razvoj novih rješenja za karakterizaciju i zaštitu brončane kulturne baštine izložene vanjskom okolišu; Title: Development of New Solutions for Characterization and Protection of Bronze Cultural Heritage Exposed to Outdoor Environment; Acronym: BroCH; Leader: Helena Otmačić Ćurković; Jurisdiction: Croatia; Funder: HRZZ; Funding stream: IP
• Study programme: Title: Applied Chemistry - Undergraduate study; specializations in: Environmental chemistry and green technologies, Advanced materials and technologies, Applied organic chemistry; Course: Advanced materials and technologies; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) primijenjene kemije (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) primijenjene kemije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2023-09-14 08:40:15