Dialdehyde 5-aminophenanthroline starch (DASAPL) was synthesized by reacting 5-aminophenanthroline with dialdehyde starch, and it was characterized through elemental analysis, FT-IR, and SEM techniques. FT-IR of DASAPL revealed the incorporation of C?N group and the disappearance of the C?O (carbonyl) group. DASAPL was used to adsorb Cd (II) from aqueous solution. The adsorption process was optimized with regard to pH, contact time, initial Cd (II) concentration, and temperature. The results revealed that the initial pH 5 and contact time of 2 h were the optimal conditions. The material showed good adsorption capacity and the adsorption data followed the Freundlich and Langmuir model. The adsorption of Cd (II) decreased with increasing temperature indicating exothermic nature of the adsorption process. Thermodynamic studies have been used to determine thermodynamic parameters of the process including Gibbs free energy, enthalpy, and entropy changes. Moreover, the adsorbents can be reused. 相似文献
A 3D spongy collagen cryogel was prepared using DAS as the cross‐linker. FTIR and CD studies demonstrate that crosslinking is achieved through the reaction of the DAS aldehyde groups with the free amino groups in collagen without affecting the triple helix of collagen. SEM demonstrates that the cryogel has a heteroporous structure with interconnecting pores. DSC measurements reveal that the cryogels have improved thermal stability in comparison with pure collagen. Moreover, the ESR shows that the water uptake of the cryogel decreases with DAS content. Evaporation tests indicate that the cryogel can hold moisture for a long time. Since both collagen and DAS are nontoxic and the resultant cryogel is blood‐compatible, the cryogel is expected to be useful, e.g., as wound dressing.
In recent years, new cross-linkers from renewable resources have been sought to replace toxic synthetic compounds of this type. One of the most popular synthetic cross-linking agents used for biomedical applications is glutaraldehyde. However, the unreacted cross-linker can be released from the materials and cause cytotoxic effects. In the present work, dialdehyde starch nanocrystals (NDASs) were obtained from this polysaccharide nanocrystal form as an alternative to commonly used cross-linking agents. Then, 5–15% NDASs were used for chemical cross-linking of native chitosan (CS), gelatin (Gel), and a mixture of these two biopolymers (CS-Gel) via Schiff base reaction. The obtained materials, forming thin films, were characterized by ATR-FTIR, SEM, and XRD analysis. Thermal and mechanical properties were determined by TGA analysis and tensile testing. Moreover, all cross-linked biopolymers were also characterized by hydrophilic character, swelling ability, and protein absorption. The toxicity of obtained materials was tested using the Microtox test. Dialdehyde starch nanocrystals appear as a beneficial plant-derived cross-linking agent that allows obtaining cross-linked biopolymer materials with properties desirable for biomedical applications. 相似文献
