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Opis: Initially the theoretical background relevant to recent developments of thermal lens spectrometry (TLS) which include TLS detection in liquid chromatography and in microfluidic flow injection analysis (μFIA) and to non-contact and non-destructive characterization of composite materials by beam deflection spectrometry (BDS) is presented. The advantages and basic characteristics of the TLS and BDS techniques are illustrated by presenting applications such as the determination of free bilirubin in endothelial cells by HPLC-TLS, studies of diffusion in Taylor-type microfluidic flows by thermal lens microscopy (TLM), μFIA-TLM detection of microcystin-LR and Cr(VI) in waters, and by the dept profiling of multi-layered coatings of orthopaedic implants. In the main part of the presentation the results of joint MU-UNG research are presented with emphasis on BDS and TLS characterisation of biocomposite materials from cellulose and chitosan or keratin with added Ag nanoparticles, sporopollenin capsules or antibiotics. The focus is on BDS determination of thermal parameters including thermal diffusivity and related properties relevant for medical applications, such as porosity and surface roughness, as well as on the TLS detection of Ag and other nanoparticles applied in studies of nanoparticle leaching from biocomposites.
Ključne besede: Optotermična spektrometrija, TLS, BDS, kemijska analiza, karakterizacija materialov, biokompoziti
Objavljeno v RUNG: 23.10.2023; Ogledov: 578; Prenosov: 1
Celotno besedilo (25,02 MB)

Opis: Organic wastes such as wood, hair, feathers, exoskeletons of crustaceans and molluscs or even water melon rind represent some examples of valuable and abundant sources of natural polymers such as cellulose, keratin and chitin, which were already extensively exploited for preparation of novel bio-composite materials. Application of green chemistry approaches for their synthesis makes such bio-composites really sustainable materials with several interesting properties for different applications, including those in environmental technology. In this review, synthesis of novel bio-composites based on cellulose (CEL), chitosan (CS - chemically modified chitin) or keratin (KER) and their potential for application in environmental technology will be presented. The synthesis is based on dissolution of bio-polymers in ionic liquids. This is the crucial step in the synthesis of such materials, which at the same time makes the process completely recyclable with regard to the solvents. The tensile strength is regulated by the proportion of CEL in the material, while higher proportions of CS were shown to add to the adsorptive and antimicrobial activity of the material [1]. Antimicrobial activity was also observed for CEL:KER materials and was further improved by decorating the bio-composites with silver or gold nanoparticles [2]. Our research has shown high potential for application of synthesised bio-composites in environmental technologies including removal of toxins or killing of pathogens in water. It was demonstrated that CEL:CS composites can remove up to 96 mg of microcystin per gram of composite, which is almost 5 times higher than best known adsorbent for microcystin [1]. On the other hand CEL:KER composites with incorporated Ag0 nanoparticles have shown up to 6 logs of reduction in the number of bacteria (99.9999% growth reduction) of bacteria such as E. coli which is a frequently encountered pathogen in wastewaters [2]. [1] TRAN, C. D., DURI, S., DELNERI, A., FRANKO, M. (2013), Chitosan-cellulose composite materials: preparation, characterization and application for removal of microcystin, Journal of hazardous materials. 252/253, p 355-366 [2] TRAN, C. D., PROSENC, F., FRANKO, M., BENZI, G. (2016, One-pot synthesis of biocompatible silver nanoparticle composites from cellulose and keratin: characterization and antimicrobial activity, ACS applied materials & interfaces. 8, p 34791-34801
Ključne besede: Trajnostni materiali, biokompoziti, celuloza, hitosan, keratin, sporopolenin, mikrocistin
Objavljeno v RUNG: 06.12.2022; Ogledov: 2429; Prenosov: 0
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