Chen, Zhao, et al. Materials Science and Engineering: C 49 (2015): 234-242.
Dioctyldimethylammonium chloride (D821) exhibits unique antibacterial properties when used as an emulsifier in the polymerization of antibacterial poly(St-co-BA) coatings. However, its poor emulsifying performance limits its application in antibacterial nanoemulsions. A direct method to address the relatively weak emulsifying ability of D821 is by adding a synergistic emulsifier, cetyltrimethylammonium bromide (CTAB).
Preparation of Antibacterial Poly(St-co-BA) Coatings
The typical basic formulation for the polymerization involves 30/30/0.36/135.3 (g) of St/BA/AIBA/H2O. Additionally, the temperature is maintained at 75 °C, and the amount of one emulsifier (either D821-CTAB or Gemini copolymer monomer (GMAP-6-MAP)) varies in each experiment. All polymerization reactions are carried out in a 500 mL four-neck flask in a constant-temperature water bath. The flask is equipped with a PTFE paddle stirrer, reflux condenser, nitrogen inlet, and dropping funnel. First, the total emulsifier, a portion of the water, and 10% of the monomers are added to the flask and stirred at 300 rpm for 40 minutes to prepare a pre-emulsion. The reactor is then heated to 75 °C. A 30% AIBA solution is added, and the stirring speed is reduced to 180 rpm. After 10 minutes, the remaining monomer, AIBA solution, and GMAP-6-MAP solution are added dropwise at a constant rate over 3.5 hours. The reaction continues at 75 °C for another 1.5 hours. The resulting latex is placed on a clean glass plate and dried at 25 °C for 7 days to form a latex film. The latex film measures 10 cm in length, 10 cm in width, and less than 0.03 cm in thickness.
Wang, H., Yu, F., Su, J., Shi, G., Pan, D., & Li, R. (2017). Ceramics International, 43(9), 7033-7039.
Mesostructured zirconia nanomaterials were prepared using dioctyldimethylammonium chloride (DDAC8), a low-cost double-chain quaternary ammonium salt, as a template in an alcohol thermal system.
Synthesis of Zirconia
Typically, 0.5 mL of TEA is slowly added to 50 mL of zirconium nitrate ethanol solution (0.3 mol/L) under stirring at room temperature. Then, 10 mL of DDAC8 ethanol solution is added dropwise to the above solution, maintaining the molar ratio of DDAC8/Zr in the synthesis system between 0.04 and 0.16. After continuous stirring for at least 1 hour, the prepared mixture is transferred to a polytetrafluoroethylene autoclave and aged at 90 °C for 4 hours. After cooling the mixture to room temperature, ammonia water is carefully added dropwise to adjust the pH to approximately 9.0, followed by vigorous stirring for 2 hours. The resulting solution is then sealed in a polytetrafluoroethylene autoclave and heated at 120 °C for 48 hours. The obtained precipitate is thoroughly washed with 95% ethanol and dried overnight at 60 °C. The prepared samples are calcined in air at 400 °C for 5 hours and are designated as Zr-0.04, Zr-0.08, Zr-0.12, and Zr-0.16.
Wang, H., Li, Y., Yu, F., Wang, Q., Xing, B., Li, D., & Li, R. (2019). Chemical Engineering Journal, 364, 111-122.
Sulfated zirconia is used as a solid acid catalyst for the esterification (transesterification) of low-quality feedstocks and free fatty acids to produce biodiesel. However, its framework and catalytic instability limit its widespread application in catalytic reactions. To address this, a stable sulfated zirconia catalyst with a mesoporous structure and tetragonal nanocrystals was prepared using dioctyldimethylammonium chloride (DDAC8) as a template.
In a typical synthesis, Zr(NO3)4·3H2O is dissolved in ethanol at room temperature, followed by the slow addition of TEA, with stirring for 0.5 hours. Then, an ethanol solution of DDAC8 is added dropwise to the above mixture. After further stirring, the prepared mixture is transferred to a polytetrafluoroethylene autoclave and aged at 90 °C for 4 hours. The molar ratio of the components is Zr:DDAC8:TEA
= 1:0.09:0.2:69. After cooling to room temperature, ammonia water is added dropwise under vigorous stirring to adjust the pH to 9.2 ± 0.2, followed by continued stirring for 2 hours. The resulting solution is sealed in a polytetrafluoroethylene autoclave and heated at 120 °C for 48 hours. Finally, the prepared samples are thoroughly washed with 95% ethanol and dried overnight at 60 °C. To remove surfactant residues and obtain amorphous zirconia, the samples are heated in air to 300 °C at a rate of 1 °C/min and held for 6 hours.
To synthesize mesoporous sulfated zirconia, 1 g of the above-prepared calcined zirconia material is stirred in 20 mL of 1.0 M sulfuric acid solution for 0.5 hours. The sample is then filtered and dried at 120 °C, followed by calcination in air at 550 °C and 600 °C for 3 hours. The catalysts prepared here are designated as MSZ550 and MSZ600.
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