Meng Minjia, Ren Jiajia, Zhang Chuanxun, Du Wanqi, Wang Jixiang
School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, China.
Molecules. 2024 Aug 15;29(16):3868. doi: 10.3390/molecules29163868.
A traditional phase transformation method is commonly used to prepare molecular imprinting membranes for selective separation. However, traditional molecularly imprinted polymers are mostly micron-sized particles, and the imprinting sites in their membrane are easily embedded, leading to a reduced adsorption capacity and decreased selectivity. In this study, an ultra-long nanowire with a diameter of about 15 nm was synthesized for the separation of artemisinin (ART), and its adsorption capacity was as high as 198.29 mg g after imprinting polymerization. Molecular imprinting membranes were prepared, using polyvinylidene fluoride (PVDF), polyethersulfone (PES), and polysulfone (PSF) as the membrane matrix, for comparison. The average membrane pore size of PVDF-MIM was about 480 nm, and PVDF-MIM had the highest adsorption capacity (69 mg g) for ART. The optimal flow rate for PVDF-MIM's dynamic adsorption of ART was 7 mL min. Under this optimal flow rate, selectivity experiments were carried out to obtain the separation factor of PVDF-MIM (α = 8.37), which was much higher than the corresponding values of PES-MIM and PSF-MIM. In addition, the hydrophobicity and low flux of PES-MIM and PSF-MIM lead to higher non-specific adsorption. The hydrophobicity of PVDF-MIM is lower than that of PES-MIM and PSF-MIM, which greatly reduces the non-specific adsorption of the membrane, thus increasing the selectivity of the membranes. Therefore, the effective density of the imprinting sites in the pores and the membrane structure are the main factors determining the efficient separation of molecularly imprinted membranes.
一种传统的相转化方法通常用于制备用于选择性分离的分子印迹膜。然而,传统的分子印迹聚合物大多是微米级颗粒,其膜中的印迹位点容易被包埋,导致吸附容量降低和选择性下降。在本研究中,合成了一种直径约为15 nm的超长纳米线用于青蒿素(ART)的分离,印迹聚合后其吸附容量高达198.29 mg/g。以聚偏氟乙烯(PVDF)、聚醚砜(PES)和聚砜(PSF)为膜基质制备分子印迹膜进行比较。PVDF-MIM的平均膜孔径约为480 nm,对ART的吸附容量最高(69 mg/g)。PVDF-MIM对ART动态吸附的最佳流速为7 mL/min。在此最佳流速下进行选择性实验,得到PVDF-MIM的分离因子(α = 8.37),远高于PES-MIM和PSF-MIM的相应值。此外,PES-MIM和PSF-MIM的疏水性和低通量导致较高的非特异性吸附。PVDF-MIM的疏水性低于PES-MIM和PSF-MIM,这大大降低了膜的非特异性吸附,从而提高了膜的选择性。因此,孔中印迹位点的有效密度和膜结构是决定分子印迹膜高效分离的主要因素。