凝胶改性基底微藻细胞黏附特性及热力学分析

为强化微藻生物膜成膜过程中藻细胞与基底黏附,同时解决藻细胞残留造成的基底重复利用性差的问题,用聚N-异丙基丙烯酰胺(PNIPAAm)温缩型凝胶修饰基底。傅里叶红外光谱分析改性表面化学特性;结合微藻培养温度给出适宜藻细胞黏附的基底浸润特性;通过构建热力学模型,明晰温度对藻细胞与温缩型凝胶改性基底界面作用自由能的影响规律,结果表明,随温度从15℃升高到30℃,藻细胞与改性基底的界面作用自由能变从-39 mJ·m-2变化到-67 mJ·m-2,即黏附能力随温度升高而增强。黏附实验表明,随温度从15℃升高到30℃,温缩型凝胶改性基底的藻细胞黏附密度提高了50%,这与热力学模型预测结果吻合,说明该模型对分析温缩型凝胶改性基底藻细胞黏附有重要指导意义。

The Adhesion Characteristics and Thermodynamic Analysis of Microalgae Cells on Modified Substrate by Gel

Aiming to enhance the adhesion of microalgae cells onto the surface during microalgae biofilm formation,and to solve the problem of poor reusability caused by the microalgae residual in the surface,a poly N-isopropylacrylamide(PNIPAAm),which is the temperature shrinkable gel,onto glass sides.The chemical properties of the modified substrate were analyzed by Fourier Transform Infrared Spectrometer.Combining with the temperature of microalgae cultivation,the wettabilityof the substrate suitable for microalgae cell adhesion was given,the effect of temperature on the interface free energy of between microalgae cells and the modified substrate was clarified by the thermodynamic model.The results showed that the interfacial free energy of between microalgae cells and the modified substrate changed from-39 mJ·m-2 to-67 mJ·m-2with the temperature increased from 15℃ to 35℃,meaning that adhesion effect of microalgae cells onto the modified surface improved with the increase of temperature.Adhesion experiments indicated that the adhesion density of microalgae cells on the modified substrate increased by 50% with the temperature enhanced from 15℃ to 30℃,which is consistent with the prediction of the thermodynamic model.These results implied that the thermodynamic analysis method has important guiding significance for the adhesion of microalgae cells onto the surface of the temperature-shrinkable gel modified substrate.