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Composites from Renewable and Sustainable Materials || Composite Coatings Based on Renewable Resources Synthesized by Advanced Laser Techniques
摘要： This chapter reviews the progress and perspectives of composite materials in the form of thin films based on renewable resources for biofabrication of a new generation of medical implants with antibacterial properties. The chapter starts with an overview of the types of renewable materials that were currently studied and of the unique properties which make them perfect candidates for numerous bio‐related applications. A briefing of recent progresses in the field of advanced laser synthesis of composites from renewable and sustainable materials, as well as the relevant results in our researches is made. The discussion spans composite coatings based on renewable resources, [e.g., chitosan (CHT) and lignin (Lig)] as biomaterials intended for metallic implants. A particular attention is given to lignin synthesis in the form of thin films due to its ability to functionalize the medical implant surface while preserving the similar composition and the structural properties of the raw, renewable biomaterial. We focused on recent technological advancements (e.g., matrix‐assisted pulsed laser evaporation (MAPLE) and Combinatorial‐MAPLE) which have brought the spotlight onto renewable biomaterials, by detailing the relevant engineering data of processing. This chapter concludes that the extensions of advanced laser techniques are viable fabrication methods of a new generation of metallic implants.
关键词： Lignin,Chitosan,Renewable,MAPLE,C‐MAPLE
更新于2025-09-09 09:28:46
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Degradation study of malachite green on chitosan films containing heterojunctions of melon/TiO2 absorbing visible-light in solid-gas interfaces
摘要： Urea modified TiO2 nanoparticles were synthesized at different TiO2: urea ratios (10, 30 and 60 (%wt) named UTiO2-10, 30 and 60) by sol-gel method and annealing at 400 °C during 1h. Characterization revealed the presence of TiO2 nanoparticles with visible light absorption (between 400 and 500 nm) probably due by the formation of thermolysis urea byproducts such as melon, which may induce a TiO2/melon heterojunction. Then, modified nanoparticles were immobilized on chitosan films by adding 30% (70QS/30UTiO2) and 50% 50QS/50UTiO2) of UTiO2 nanoparticles. Functionalized films were characterized by SEM-EDS, DRS and AFM. Photo-induced degradation of malachite green stains was evaluated on these films under different wavelengths. Upon UV-A+visible light irradiation, films showed good activity even slightly better than those containing Evonik P-25 (70QS/30P-25). Upon visible light between 450 and 800 nm, films evidenced a satisfactory performance but slower than under UV-A+visible light irradiation whereas the photobleaching activity of 70QS/30P-25 was very poor. When visible light irradiation with wavelengths higher than 590 nm was used, a slight photobleaching was also observed. DRS spectra taken at different irradiation times showed that dye underwent N-demethylated oxidative reactions either upon UV-Visible or visible light irradiation. ATR-FTIR measurements revealed the generation of benzophenones after 6 h of irradiation probably suggesting the formation of singlet oxygen under visible light. 70QS/30UTiO2-10 films showed a good photo-bleaching activity after 18 h of continuous UV-A+visible light irradiation.
关键词： urea,Visible-light responsive TiO2,chitosan films,melon/TiO2 heterojunction
更新于2025-09-09 09:28:46
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Preparation of TiO2/Fe2O3/Chitosan Nanocomposite Films and Its Photocatalytic Degradation of Rhodamine B
摘要： A new photocatalytic thin films TiO2/Fe2O3/chitosan was synthesized by a solution casting technology to degrade the azo coloured compounds in the industrial waste water. The prepared TiO2/Fe2O3/chitosan was characterized by X-ray diffraction, scanning electron microscopy and high-resolution transmission electron microscopy (HRTEM). TiO2 and Fe2O3 were entrpped in the chitosan film uniformly. The catalytic ability of TiO2/Fe2O3/chitosan was evaluated by photodegradtion of Rhodamine B. About 99.4 % Rhodamine B were photodegraded by 0.5 g L-1 photocatalyst under solar lights irradiation for 120 min. The influence of the reaction pH has been well investigated. And TiO2/Fe2O3/chitosan has good stability and reusability, it is suitable for the practical industrial waste water treatment.
关键词： Photocatalytic degradation,Chitosan,Fe2O3,TiO2
更新于2025-09-04 15:30:14