电气石微胶囊的制备及性能研究

Preparation and performance study of tourmaline microcapsules

以乙基纤维素为壁材,电气石粉体为芯材,采用乳化-溶剂蒸发法制备电气石微胶囊,通过单因素实验分析了工艺条件对电气石微胶囊负载量和粒径的影响,利用扫描电子显微镜、傅里叶变换红外光谱仪、热分析仪和空气离子计数器等对微胶囊的微观形貌、结构、热稳定性、负载量以及负氧离子释放性能进行表征。结果表明:在芯壁质量比为1∶2、乳化剂含量为连续相溶剂的0.5%、搅拌速度为400r/min、溶剂挥发温度为57℃时,微胶囊负载量达到46.2%(质量分数),平均粒径为20.3μm;电气石粉体被乙基纤维素有效包覆,电气石微胶囊呈规则的球状,表面光滑,壳层上分布着大量的孔道。热重分析表明电气石微胶囊在200℃后才有明显的质量损失,热稳定性较好。负氧离子动态释放量大约15d达到平衡稳定状态,释放量约为850个/cm^(3)。

The tourmaline microcapsules were prepared by emulsification-solvent evaporation method using ethyl cellulose as wall material and tourmaline powder as core material.The effects of different process conditions on the loading capacity and particle size of tourmaline microcapsules were verified by controlling single-factor tests.The microcapsules were characterized by scanning electron microscopy,Fourier infrared thermal analyzer and air ion counter to evaluate the microstructure,capacity,thermal stability as well as performance of releasing negative oxygen ions.The results proved that the loading capacity of tourmaline microcapsules was 46.2%(mass fraction),and the average particle size was 20.3μm at the ratio of core to shell of 1∶2,emulsifier dosage of 0.5%,stirring speed of 400r/min and solvent evaporation temperature of 57℃.The tourmaline powder was effectively coated with ethyl cellulose,and the tourmaline microcapsules were in a regular spherical shape with a smooth surface and a large number of pores distributed on the shell layer.The TG analysis revealed that the obvious mass loss of tourmaline microcapsules could be found only at the temperature higher than 200℃,indicating good thermal stability.The dynamic release of negative oxygen ions reached a stable equilibrium state within approximately 15 days,with a release amount of about 850 ions/cm^(3).