In this study, a stable antibacterial poly(styrene-co-butyl acrylate) (poly(St-co-BA)) nano-latex was prepared in the presence of a dioctyldimethylammonium chloride (D821)-CTAB mixed surfactant and a novel bis -unsaturated Gemini comonomer (i.e., α, ω -hexanediyl bis (dimethyl methacrylamidopropyl ammonium bromide) (G MAP-6-MAP )) using a feasible and mild semicontinuous technology. The effects of the emulsifiers and G MAP-6-MAP on the properties and antibacterial activities of poly(St-co-BA) coatings were systematically investigated. The results indicate that an optimal monodispersed stable nanoemulsion was obtained with Dw = 58.24 nm and PDI = 0.026, the emulsifier amount was 3.75% (D821/CTAB = 4:1), and the G MAP-6-MAP amount was 1.5%. CTAB improved the stabilities and antibacterial activities of the poly(St-co-BA) nanoemulsions. The incorporation of G MAP-6-MAP into poly(St-co-BA) can enhance the antibacterial activity, improve the thermal stability of latex films, as well as the consistency among the chain segments, and decrease the roughness of latex films. This nanoemulsion exhibits effective antibacterial activity with MBCs of 2 μg·mL − 1 against Staphylococcus aureus and 16 μg·mL − 1 against Escherichia coli . The sterilization rates of the optimized latex film reached 100% against S. aureus and 98.74% against E . coli , which indicated that this latex film could be utilized as an outstanding antibacterial coating.
Lu-Lu Yang,Xue-Wei Wei,Tianyu Wu,Xiaoyu Meng,Hai-Mu Ye
Isomorphism is a distinctive kind of co-crystallization behavior of random copolymers and provides opportunities to regulate the crystalline structure and performance without the loss of crystallinity. Though the intrinsic structural differentiation would induce variation of accommodation capacity in the co-crystal lattice for different co-monomeric units, subtle manipulation of isomorphism has not been realized yet. In this study, butylene adipate (BA) as the crystallizable unit is incorporated into an isomorphism system model of poly(butylene succinate-ran-butylene fumarate) (PBSF) to form the terpolymers of PBSFA, and the crystallization features are investigated. It is confirmed that part of BA (i.e., ≤20 mol %) does not hinder the isomorphism formation in the terpolymers of PBSFA but influences the accommodation capacities of the isomorphic counterparts of butylene succinate (BS) and butylene fumarate (BF). When BA with 10 mol % is copolymerized, the adoption of BS unit in isomorphism becomes less favorable in comparison to the biopolymers of PBSF, showing an increase of the defect Gibbs free energy for the co-crystal and a decrease of the accommodation ratio of BS. However, with a further lifting of the BA content to 20 mol %, the accommodation preference of BS and BF in the isomorphism lattice reverses, and BS turns into a favorable unit instead of BF. Such a transition of accommodation capacity might be due to the deterioration of intersegmental interaction caused by the third co-crystallizable unit of BA. This work directly reveals the differentiation of co-monomeric units in the isomorphic lattice and sheds light on the manipulation of isomorphism.
危险品化学品经营许可证（带存储）