Hao Chuanming, Cui Yuezhi, Yang Pengfei, Zhang Huayong, Mao Dejiang, Cui Xiao, Li Junying
Shandong Provincial Key Laboratory of Fine Chemicals, Qilu University of Technology, Jinan 250353, China.
School of Food & Bioengineering, Qilu University of Technology, Jinan 250353, China.
Colloids Surf B Biointerfaces. 2015 Apr 1;128:528-536. doi: 10.1016/j.colsurfb.2015.03.004. Epub 2015 Mar 7.
A series of organosilicon Bola-form bi-quaternary ammonium amphiphiles, [OH5C3(C2H5)2N+-(CH2)3-Si(CH2)3-O-(Si(CH3)2O)n-Si(CH2)3⋯(CH2)3-N+(C2H5)2C3H5O]Cl2- (SinN2Cl2, n=0, 4, 6, 8), with the same headgroups and different length of hydrophobic linkage has been synthesized. The critical micelle concentration (CMC) of each amphiphiles was determined by equilibrium surface tension. With the increased length of hydrophobic siloxane spacer, the CMC values follow the order of Si8N2Cl2<Si6N2Cl2<Si4N2Cl2<Si0N2Cl2. At the same time, thermodynamic parameters (ΔGm0, ΔHm0, ΔSm0) of micellization were calculated by Gibbs equation under the mass action model. It indicates that the micellization of the amphiphiles in aqueous solution is entropy-driven. Especially, the surface area (Amin) of Si4N2Cl2 is the largest attributing to the interaction of free-rotated siloxane spacer and its internal oxygen atom, which make the molecular stretch free. The antimicrobial property of Si4N2Cl2 is more effective than others below the concentration of CMC, while the antimicrobial property of Si8N2Cl2 is more effective above the concentration of CMC, which indicated that both the adsorbability in formation of micellar and the hydrophobicity arising from the different length of siloxane spacer are important to inhibit microbe. Moreover, their wetting ability has been characterized by contact angles on various material surfaces. It shows that the higher weight of lipophilic siloxane spacer leads to lower contact angels.
合成了一系列具有相同头基和不同疏水链长度的有机硅bola型双季铵两亲物[OH5C3(C2H5)2N+-(CH2)3-Si(CH2)3-O-(Si(CH3)2O)n-Si(CH2)3⋯(CH2)3-N+(C2H5)2C3H5O]Cl2-（SinN2Cl2，n = 0、4、6、8）。通过平衡表面张力测定了每种两亲物的临界胶束浓度（CMC）。随着疏水硅氧烷间隔基长度的增加，CMC值的顺序为Si8N2Cl2＜Si6N2Cl2＜Si4N2Cl2＜Si0N2Cl2。同时，在质量作用模型下通过吉布斯方程计算了胶束化的热力学参数（ΔGm0、ΔHm0、ΔSm0）。结果表明，两亲物在水溶液中的胶束化是由熵驱动的。特别是，Si4N2Cl2的表面积（Amin）最大，这归因于自由旋转的硅氧烷间隔基与其内部氧原子的相互作用，使得分子伸展自由。在CMC浓度以下，Si4N2Cl2的抗菌性能比其他物质更有效，而在CMC浓度以上，Si8N2Cl2的抗菌性能更有效，这表明胶束形成过程中的吸附性和由不同长度硅氧烷间隔基产生的疏水性对抑制微生物都很重要。此外，通过在各种材料表面的接触角表征了它们的润湿性。结果表明，亲脂性硅氧烷间隔基的重量越高，接触角越低。
