1. Green synthesis and characterization of colloidal silver using flower honey at different pH values : master thesis
- Author
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Gobin, Valentino and Barbir, Damir
- Subjects
FT-IR ,koloidno srebro ,zelena sinteza ,Tyndallov efekt ,Tyndall efect ,green synthesis ,TEHNIČKE ZNANOSTI. Kemijsko inženjerstvo ,TECHNICAL SCIENCES. Chemical Engineering ,colloidal silver ,UV-Vis ,cvjetni med ,flower honey - Abstract
Brojna izvješća koja se nalaze u literaturi ukazuju na štetnost i ekološku neprihvatljivost sinteze nanočestica kemijskim putem. Stoga postoji rastuća potreba za razvojem ekološki prihvatljivijih i ekonomski izvedljivijih procesa koji ne koriste otrovne kemikalije u procesu sinteze. U ovom radu proučavana je zelena sinteza koloidnog srebra pomoću cvjetnog meda pri pH vrijednostima 6, 7, 8, 9 i 10. Prilikom sinteze korištene su ultra čista voda, otopina cvjetnog meda, otopina srebrova nitrata koncentracije 0,001 mol dm -3 i otopina natrijevog hidroksida koncentracije 0,1 mol dm -3 . Nakon sinteze, izvršena je provjera postojanja koloidnog srebra i koncentracije srebra u otopini propuštanjem laserske zrake kroz otopinu, što je dovelo do pojave Tyndallovog efekta kod svih uzoraka. Karakterizacija dobivenih uzoraka koloida srebra provedena je UV-Vis spektrofotometrijom u području valnih duljina od 300 do 800 nm i FT-IR spektrometrijom u području valnih brojeva od 4000 do 650 cm -1 . Rezultati UV- Vis spektroskopske analize pokazali su pojavu površinskog plazmona rezonancije kod svih uzoraka. Intenziteti apsorbancije ukazuju na povoljnije uvjete odvijanja reakcija pri višim pH vrijednostima. FT- IR mjerenja su provedena kako bi se identificirale moguće biomolekule odgovorne za nastanak i stabilizaciju nanočestica srebra sintetiziranih korištenjem meda. Male razlike u valnim brojevima i intenzitetima apsorpcijske vrpce opažene su u spektrima uzoraka koloidnog srebra pri različitim pH vrijednostima. A number of reports prevailed in the literatures indicate that synthesis of nanoparticles by chemical approaches are eco unfriendly and expensive. Thus, there is a growing need to develop environmentally and economically friendly processes, which do not use toxic chemicals in the synthesis protocols. In this paper, the green synthesis of colloidal silver using floral honey was studied at pH values of 6, 7, 8, 9 and 10. During the synthesis, ultrapure water, floral honey solution, silver nitrate solution with a concentration of 0.001 mol dm -3 and sodium hydroxide solution with a concentration of 0,1 mol dm -3 were used. After the synthesis, the presence of colloidal silver and the concentration of silver in the solution were checked by passing a laser beam through the solution, which led to the appearance of the Tyndall effect in all samples. Characterization of the obtained silver colloid samples was carried out by UV-Vis spectrophotometry in the wavelength range from 300 to 800 nm and by FT-IR spectrometry in the wavelength range from 4000 to 650 cm -1 . The results of UV-Vis spectroscopic analysis showed the appearance of surface plasmon resonance in all samples. The absorbance intensities indicate more favorable conditions for reactions at higher pH values. FT-IR measurements were performed to identify possible biomolecules responsible for the formation and stabilization of silver nanoparticles synthesized using honey. Small differences in wave numbers and absorption band intensities were observed in the spectra of colloidal silver samples at different pH values.
- Published
- 2022