制备均匀粒度分布的棕榈醇-棕榈酸-月桂酸@(Ce-La-TiO2)光-热-湿复合材料

摘要

以Ce-La-TiO2空心微球作为载体材料,棕榈醇(H)-棕榈酸(PA)-月桂酸(LA)作为相变材料,采用溶胶-凝胶法和真空吸附法制备 H-PA-LA@(Ce-La-TiO2)光-热-湿复合材料.通过均匀设计与径向基函数(RBF)神经网络结合,考察制备因素(如磁力搅拌转速、恒温回流温度、煅烧升温速度和真空恒温干燥箱真空度)对H-PA-LA@(Ce-La-TiO2)光-热-湿复合材料粒度分布的影响,并且对粒度分布最均匀的 H-PA-LA@(Ce-La-TiO2)光-热-湿复合材料进行表征与测试.结果表明,当扩展系数为0.45~0.55时,RBF神经网络具有最佳的逼近效果.粒度分布最均匀 H-PA-LA@(Ce-La-TiO2)光-热-湿复合材料的制备工艺参数为:磁力搅拌转速为1762 r/min、恒温回流温度为66.9℃、煅烧升温速度为2.43℃/min和真空恒温干燥箱真空度为0.58 MPa.基于上述制备参数,中位径d50为190.02 nm,粒径分布区间的实测值为180.50 nm,实测值与预测值吻合较好,相对误差为3.58%.在相对湿度35%~85%的平衡含湿量为0.0369~0.1702 g/g,相变温度为24.21~29.48℃,相变焓为31.24~33.07 J/g,经过5 h对甲醛的降解效率为56.92%.%With Ce-La-TiO2hollow microspheres and hexadecanol (H)-palmitic acid (PA)-lauric acid (LA)as carrier material and phase change material respectively,H-PA-LA@(Ce-La-TiO2)photocatalytic-heat-mositure composites were made by sol-gel method and the vacuum adsorption method.By combining the uniform design and radial basis function(RBF)neural network,the effect of preparation factors (i.e.speed of the magnetic stirring, temperature of constant temperature reflow,rate of increase in calcining and vacuum degree of vacuum thermostatic oven)on particle size distribution of the H-PA-LA@(Ce-La-TiO2)photocatalytic-heat-mositure composites was in-vestigated experimentally.In addition,the H-PA-LA@(Ce-La-TiO2)photocatalytic-heat-mositure composites with optimal uniform particle size distribution was tested and characterized.The results show that RBF neural network has the best approximation effect when spreading coefficient is 0.45~0.55.To obtain H-PA-LA@(Ce-La-TiO2) photocatalytic-heat-mositure composites with optimal uniform particle size distribution,the preparation parameters were identified as follows:magnetic stirring speed of 1 762 r/min,temperature of constant temperature reflow of 66.9℃,increase rate in calcining of 2.43℃/min and vacuum of vacuum thermostatic oven of 0.58 MPa.On the base of the above preparation parameters,median diameter d50is 190.02 nm,the measured value of particle size dis-tribution range is 180.50 nm.The measured value agrees well with the predictive value (relative error is 3.58%). In the case of relative humidity between 35% and 85%,the equilibrium moisture content is obtained to be between 0.0369 g/g and 0.1702 g/g,phase transition temperature between 24.21℃ and 29.48℃,phase change enthalpy be-tween 31.24 J/g and 33.07 J/g,and formaldehyde degradation rate reaches 56.92% after 5 h.