摘要
研究采用高速剪切搅拌法制备了以疏水性纳米粉体为外壳、内部含水的类胶囊状"干水"(DW)粉体,通过将水替换为海藻酸钠溶液制备了海藻酸钠-"干水"(SA-DW)粉体,利用海藻酸Ca2+交联反应形成凝胶的特性制备了海藻酸钙凝胶-"干水"(CA-DW)粉体。通过显微镜观察3种粉体形态的差异,对比制备条件对产物形态的影响。利用流出速度和堆积角表征粉体的流动性,通过静态压力实验和离心实验对比3种粉体的耐压性和稳定性。结果表明,DW粉体颗粒形态较不均匀,其堆积角>30°,在离心转速为1 000r/min时就会被破坏;SA-DW粉体形态较为均匀,其堆积角<30°,在离心转速为2 000r/min时会被破坏;CA-DW的粉体形态与SA-DW粉体类似,其堆积角<30°,在4 000r/min离心转速下只有少量水被离心释放出来。相比于DW粉体,CA-DW粉体的流动性、耐压性都有较大的提升。
In this work, the microcapsule-like “dry water” （DW） powder with hydrophobic SiO 2 nanoparticles as shell and water as core is prepared by high-speed shear agitation. Then the water is replaced by sodium alginate solution to prepare sodium alginate “dry water” （SA-DW） powder. Taking the advantages of the crosslinking reaction between sodium alginate and Ca 2＋ , the gelling Ca-alginate “dry water” （CA-DW） powder is obtained. The morphology difference among these three powders is compared, and the influence of experimental conditions on the morphology is studied. The fluidity of powder is characterized with flow velocity and repose angle. The pressure resistance and stability are studied with static pressure experiment and centrifugation. The results indicate that the DW particle is morphologically uneven, and its repose angle is larger than 30°. This “dry water” powder is completely destroyed even at low centrifugal rotational speed of 1 000 r/min. SA-DW powder is relatively morphologically uniform, and its repose angle is less than 30°. The particle is collapsed at centrifugal rotational speed of 2 000 r/min. CA-DW powder particles are similar to SA-DW powder with a repose angle of 25°, and only little water is released under the centrifugal rotational speed of 4 000 r/min. The CA-DW powder has a higher fluidity and compressibility compared with DW powder.
作者
张祖忞
袁必和
李欣
陈先锋
ZHANG Zumin;YUAN Bihe;LI Xin;CHEN Xianfeng(School of Resources 0x0E？Symbolf@@0x0F Environmental Engineering,Wuhan University of Technology,Wuhan 430070,China)
出处
《功能材料》
EI
CAS
CSCD
北大核心
2018年第6期107-113,共7页
Journal of Functional Materials
基金
国家"十三五"重点研发计划专题资助项目(2017YFC0804705)
国家自然科学基金资助项目(51774221,51374164)。
