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The carbonization of collagen-based leather waste to nitrogen-containing carbon is reviewed with respect to the preparation, characterization of carbonized products, and applications proposed in the literature. The resulting nitrogen-containing carbons with fibrous morphology have been used as adsorbents in water pollution treatment, in electrocatalysis, and especially in electrodes of energy-storage devices, such as supercapacitors and batteries. Although electrical conductivity has been implicitly exploited in many cases, the quantitative determination of this parameter has been addressed in the literature only marginally. In this report, attention has been newly paid to the determination of conductivity and its dependence on carbonization temperature. The resulting powders cannot be compressed into pellets for routine conductivity determination. A new method has been used to follow the resistivity of powders as a function of pressure up to 10 MPa. The conductivity at this pressure increased from 9.4 × 10−8 S cm−1 for carbonization at 500 °C to 5.3 S cm−1 at 1000 °C. The conductivity of the last sample was comparable with conducting polymers such as polypyrrole. The carbonized leather thus has the potential to be used in applications requiring electrical conduction., Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMT: INTER-EXCELLENCE LTT20005, RO70200003025/2102, Ministry of Education, Youth, and Sports of the Czech Republic [INTER-EXCELLENCE LTT20005, RO70200003025/2102]

Son on yıllarda, nanokristalin selüloz (NCC), iyi mekanik mukavemet, yüksek yüzey alanı, düşük yoğunluklu, yarı kristal yapı, biyouyumluluk, biyo-bozunabilirlik ve çevresel sürdürülebilirliği içeren çekici özelliklere sahip olduğunu göstermiştir. Bu doktora çalışması, günümüzün potansiyel uygulamaları için benzersiz özelliklerinden yararlanarak yüzey modifiye NCC'yi kullanmaktır. Doğal selülozdan NCC verimi, yanıt yüzey metodolojisi (RSM) ile değerlendirildi ve optimize edildi. İzole edilmiş NCC'ler, aminlenmiş nanokristalin selüloz (A-NCC) oluşturan epiklorohidrin aracılı aminasyon yoluyla modifiye edilmiş yüzeylerdir. NCC ve A-NCC için ortalama partikül büyüklüğü FTIR, TEM. TGA ve XRD teknikleri. A-NCC nanopartikülleri daha sonra biyoaktif bileşiklerin kontrol salımı için su içinde yağlama yoluyla bir Pickering emülsiyon formüle sistemde stabilizörler olarak uygulandı. Ek olarak, antikanser ve antimikrobiyal aktiviteler değerlendirildi. Başka bir çalışmada da, A-NCC'nin mikrolevha jeller jelleri de hazırlandı ve boronun iyileşmesi için uygulandı. Sulu fazdan bor alımını etkileyen girdi faktörlerinin etkisini ve önemini araştırmak amacıyla Taguchi model tasarımı uygulanmıştır. Ayrıca, adsorpsiyon sürecinin yanı sıra biyo-emicinin yeniden kullanılabilirlik özelliklerini ortaya çıkarmak için geri kazanım kinetikleri ve termodinamik değerlendirmeler de gerçekleştirilmiştir. Ayrıca, biyo-emici madde olarak sentezlenmiş kitosan-montmorillonit hidrojel ile bakır (II) iyonları ve suda çözünebilir Nitrazin Sarı (NY) boyalarının adsorpsiyonu üzerine bir karşılaştırmalı çalışma araştırılmıştır. Adsorbasyon ve biyo-emici etkileşimi en iyi şekilde tanımlamak için adsorpsiyonun yanı sıra kinetik, termodinamik ve izotermik modelleme için optimum koşulları öngörmek amacıyla Box-Beknhen tasarımı ile yanıt yüzey metodolojisi uygulanmıştır. Over the last decades, nanocrystalline cellulose (NCC) has demonstrated to possess attractive characteristics which includes good mechanical strength, high surface area, low density, semi-crystalline structure, biocompatibility, biodegradability, and environmental sustainability. This PhD study is to utilize surface modified NCC by taking advantage of its unique properties for potential present-day applications. NCC yield from native cellulose was evaluated and optimized by response surface methodology (RSM). Isolated NCCs were surface modified via epichlorohydrin-mediated amination forming aminated nanocrystalline cellulose (A-NCC). The average particle size for NCC and A-NCC were determined as well as structural analysis by FTIR, TEM, TGA and XRD techniques. A-NCC nanoparticles were then applied as stabilizers in a Pickering emulsion formulated system via oil-in-water approach for control release of bioactive compounds. In addıtion, anticancer and antimicrobial activities were assessed. In another study, platelet shaped gels of A-NCC were also prepared and applied for enhanced recovery of boron. Taguchi model design was applied in order to investigate the effect and significance of input factors influencing boron uptake from aqueous phase. Recovery kinetics and thermodynamic evaluations were also performed to elucidate the adsorption process as well as reusability features of the bioadsorbent. Furthermore, a comparative study on adsorption of copper (II) ions and a water-soluble Nitrazine Yellow (NY) dye by synthesized chitosan-montmorillonite hydrogel as the bioadsorbent was investigated. Response surface methodology by Box-Beknhen design was applied to predict optimum conditions for adsorption as well as kinetics, thermodynamics and isothermic modelling to best describe the adsorbate and bioadsorbent interaction. 168