壳聚糖/磺丁基-β-环糊精纳米粒子的制备及其对海藻酸钠膜物理性能的影响

Preparation of Chitosan Sulfobutylether-β-Cyclodextrin Nanoparticles and Its Effect on the Physical Properties of Sodium Alginate Film

以壳聚糖(chitosan,CS)和磺丁基-β-环糊精(sulfobutylether-β-cyclodextrin,SBE-β-CD)为原料制备CS/SBE-β-CD纳米粒子,通过单因素试验探究不同条件对CS/SBE-β-CD纳米粒子粒径、多分散系数(polydispersity index,PDI)和Zeta电位的影响,得到CS/SBE-β-CD纳米粒子制备的最佳条件,并以透射电子显微镜(transmission electron microscope,TEM)和傅里叶变换红外光谱(Fourier transform infrared spectroscopy,FTIR)对CS/SBE-β-CD纳米粒子进行结构表征,探究添加CS/SBE-β-CD纳米粒子对海藻酸钠膜机械性能(拉伸强度、断裂延伸率)以及物理性能(膜厚度、水蒸气透过率(water vapor permeability,WVP))的影响。结果表明,CS/SBE-β-CD纳米粒子的最佳条件为CS分子质量100 kDa、CS溶液pH 4.0、CS质量浓度0.75 mg/mL、CS与SBE-β-CD质量比0.8∶1。该条件下制备的CS/SBE-β-CD纳米粒子粒径、PDI以及Zeta电位分别为245.1 nm、0.068和+30.2 mV。TEM观察发现CS/SBE-β-CD纳米粒子粒径均一且为规则球形。FTIR分析结果显示,CS与SBE-β-CD之间发生了静电结合,同时CS/SBE-β-CD纳米粒子形成后氢键作用增强。与空白海藻酸钠膜溶液相比,当膜溶液中CS/SBE-β-CD纳米粒子的质量浓度为1.00 mg/mL时,复合膜的拉伸强度由18.18 MPa增加到29.15 MPa,断裂延伸率由38.91%下降至26.42%,WVP由0.36 g·mm/(m^(2)·h·kPa)下降至0.21 g·mm/(m^(2)·h·kPa)。本研究制备的CS/SBE-β-CD纳米粒子能够改善和提高海藻酸钠膜的机械性能与物理性能。

In order to establish optimal conditions for preparing nanoparticles from chitosan(CS)and sulfobutylether-β-cyclodextrin(SBE-β-CD),the effects of different preparation conditions on the particle size,polydispersity index(PDI)and zeta potential of nanoparticles were studied by single factor experiments.The nanoparticles were characterized by transmission electron microscopy(TEM)and Fourier transform infrared spectroscopy(FTIR).Further,the effects of adding the nanoparticles to sodium alginate film on its mechanical properties(tensile strength,elongation at break)and physical properties(film thickness and water vapor permeability)were investigated.The results showed that the optimum conditions for preparing the nanoparticles were as follows:use of CS with molecular mass of 100 kDa;pH of CS solution,4.0;CS concentration,0.75 mg/mL,and mass ratio of CS to SBE-β-CD,0.8:1.The particle size,PDI and zeta potential of the nanoparticles prepared under the optimized conditions were 245.1 nm,0.068,and+30.2 mV,respectively.Under TEM,it was observed that the nanoparticles were uniform and regular spheres.FTIR showed that CS was electrostatically combined with SBE-β-CD,leading to enhanced hydrogen bonding.The tensile strength of the composite film with 1.00 mg/mL of CS/SBE-β-CD nanoparticles increased from 18.18 to 29.15 MPa,the elongation at break decreased from 38.91%to 26.42%,and the water vapor permeability rate dropped from 0.36 to 0.21 g·mm/(m^(2)·h·kPa)compared with those of the blank control group.From these results,it was demonstrated that the addition of CS/SBE-β-CD nanoparticles could improve the mechanical and physical properties of sodium alginate film.