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采用碳酸钠为催化剂,室温下制备了水溶性的马来酰化壳聚糖,研究了反应物投料比对酰化取代度以及产物水溶性的影响。红外光谱结果说明马来酸酐成功接枝到壳聚糖分子上;XRD结果说明马来酸酐酰化破坏了壳聚糖分子内和分子间的氢键作用,使水溶性大大提高。用Nano-ZS90Malvern仪器对不同pH值下的粒子粒径和Zeta电位进行测定,发现存在1个等电点:pH=3.01。文章首次采用自组装方法分别在醋酸、甲酸、乳酸溶液中制备得到三种不同的马来酰化壳聚糖纳米粒子并用SEM做了表征;DLS测试表明,当pH值增大后,三种纳米粒子粒径均由几十纳米溶胀到几百纳米,显示具有pH响应性。
Water-soluble maleated chitosan was prepared at room temperature using sodium carbonate as catalyst. The effect of reactant feed ratio on the degree of substitution of acylation and water solubility of the product was investigated. The result of FTIR showed that the maleic anhydride was successfully grafted onto the chitosan molecules. The XRD results showed that the maleic anhydride acylation destroyed the intramolecular and intermolecular hydrogen bonding of the chitosan and greatly enhanced the water solubility. The particle size and zeta potential at different pH values were measured with a Nano-ZS90 Malvern instrument and found to have one isoelectric point: pH = 3.01. Three different maleated chitosan nanoparticles were prepared by self-assembly method in acetic acid, formic acid and lactic acid solution for the first time and were characterized by SEM. DLS test showed that when pH value increased, The particle size is swollen from a few tens of nanometers to a few hundred nanometers, showing a pH-responsive.