Lu Dengrong, Liu Hongbo, Tang Zhishu, Wang Mei, Song Zhongxing, Zhu Huaxu, Qian Dawei, Shi Xinbo, Li Guolong, Li Bo
Co-Construction Collaborative Innovation Center for Chinese Medicine Resources Industrialization by Shaanxi & Education Ministry, Shaanxi University of Chinese Medicine, Xianyang 712038, China.
State Key Laboratory of Research & Development of Characteristic Qin Medicine Resources (Cultivation), Shaanxi University of Chinese Medicine, Xianyang 712038, China.
Membranes (Basel). 2022 Jul 28;12(8):740. doi: 10.3390/membranes12080740.
Due to the diversity and complexity of the components in traditional Chinese medicine (TCM) extracts, serious membrane fouling has become an obstacle that limits the application of membrane technology in TCM. Pectin, a heteropolysaccharide widely existing in plant cells, is the main membrane-fouling substance in TCM extracts. In this study, a hydrophilic hybrid coating was constructed on the surface of a polyvinylidene fluoride (PVDF) ultrafiltration (UF) membrane co-deposited with polydopamine (pDA) and (3-Aminopropy) triethoxysilane (KH550) for pectin antifouling. Characterization analysis showed that hydrophilic coating containing hydrophilic groups (-NH, Si-OH, Si-O-Si) formed on the surface of the modified membrane. Membrane filtration experiments showed that, compared with a matched group (FRR: 28.66%, Rr: 26.87%), both the flux recovery rate (FRR) and reversible pollution rate (Rr) of the pDA and KH550 coated membrane (FRR: 48.07%, Rr: 44.46%) increased, indicating that pectin absorbed on the surface of membranes was more easily removed. Based on the extended Derjaguin-Laudau-Verwey-Overbeek (XDLVO) theory, the fouling mechanism of a PVDF UF membrane caused by pectin was analyzed. It was found that, compared with the pristine membrane (144.21 kT), there was a stronger repulsive energy barrier (3572.58 kT) to confront the mutual adsorption between the coated membrane and pectin molecule. The total interface between the modified membrane and the pectin molecule was significantly greater than the pristine membrane. Therefore, as the repulsion between them was enhanced, pectin molecules were not easily adsorbed on the surface of the coated membrane.
由于中药提取物中成分的多样性和复杂性，严重的膜污染已成为限制膜技术在中药领域应用的障碍。果胶是一种广泛存在于植物细胞中的杂多糖，是中药提取物中的主要膜污染物质。在本研究中，通过聚多巴胺（pDA）和（3-氨丙基）三乙氧基硅烷（KH550）共沉积在聚偏氟乙烯（PVDF）超滤（UF）膜表面构建了一种亲水性杂化涂层，用于抗果胶污染。表征分析表明，改性膜表面形成了含有亲水基团（-NH、Si-OH、Si-O-Si）的亲水性涂层。膜过滤实验表明，与对照组（通量恢复率（FRR）：28.66%，可逆污染率（Rr）：26.87%）相比，pDA和KH550涂层膜的通量恢复率（FRR：48.07%，Rr：44.46%）和可逆污染率均有所提高，表明吸附在膜表面的果胶更容易被去除。基于扩展的Derjaguin-Laudau-Verwey-Overbeek（XDLVO）理论，分析了果胶对PVDF超滤膜的污染机理。研究发现，与原始膜（144.21 kT）相比，涂层膜与果胶分子之间存在更强的排斥能垒（3572.58 kT），以对抗它们之间的相互吸附。改性膜与果胶分子之间的总界面明显大于原始膜。因此，随着它们之间排斥力的增强，果胶分子不易吸附在涂层膜表面。
