双重致孔制备中空胶囊

Preparation of hollow capsules using dual pore-forming method

高分子大胶囊在医疗、化工、环境、能源等领域都有着广泛的应用,目前的制备方法多是单纯的物理或化学方法,对胶囊的孔隙率,尺寸大小等结构的控制也较为困难。以N,N二甲基甲酰胺为溶剂,聚偏氟乙烯为成囊高分子,硼氢化钠为发泡剂,水为凝固浴,在相分离和硼氢化钠发泡的双重致孔作用下制备出了具有大囊腔高孔隙率的中空胶囊。同时,还研究了硼氢化钠的浓度、温度等因素对胶囊结构的影响,并提出了分相-发泡理论,为制备不同尺寸和孔隙率的胶囊提供了理论依据,也为胶囊进一步的广泛应用提供了可能。

Polymer macrocapsules have wide applications in medical, chemical,environmental and energy engi-neering fields. At present, the most preparation methods are only simple physical or chemical process, in which control of the porosity and size of the capsule is difficult. In this paper, hollow capsule with high porosity is pre-pared using dual pore-forming method （phase inversion and gas foaming）. In the process, N,N dimethyl formamide,poly （vinylidene fluoride）,sodium borohydride and water are used as solvent , solute, the foaming a-gent and coagulation bath, respectively. At the same time, this paper also studied the influence of sodium boro- hydride concentration, temperature and other factors on the structure of the capsule and put forward the phase separation-foaming theory, which provides the theoretical basis for the preparation of different size and porosity of the capsule, and a chance for the further wide use of the capsule.