具有离子响应性的聚(1-乙烯基-3-乙基咪唑四氟硼酸盐)@CaO微胶囊的表征及触发释放

采用相分离法合成了具有离子响应性的聚（1-乙烯基-3-乙基咪唑四氟硼酸盐）（PVEIm+BF₄-）@CaO微胶囊。聚离子液体（PILs）的BF₄-与水溶液中的Cl-发生离子交换使疏水性的交联PILs壳转变为亲水性,在水中形成亲水通道。PVEIm+BF₄-@CaO微胶囊内部的CaO从通道被释放到水中形成Ca（OH）₂。PVEIm+BF₄-@CaO微胶囊加入后,NaCl水溶液中Cl-的浓度由8.3 mmolL-1降低至5.8 mmolL-1,pH值由7.00增加至11.83。提高反应物中的离子液体（ILs）的加入量、苯乙烯（St）∶二乙烯基苯（DVB）的质量比或水溶液中Cl-的浓度均可提高PVEIm+BF₄-@CaO微胶囊中CaO的释放速率。不同含量单体组成的微胶囊或被不同浓度Cl-触发的微胶囊内的CaO均可被全部释放至NaCl溶液中。溶液中的最大Ca2+浓度基本一致,约为3.4 mmolL-1。SO₄2-也可触发微胶囊的释放。结果表明,PVEIm+BF₄-@CaO微胶囊对Cl-和SO₄2-具有良好的响应性。加入PVEIm+BF₄-@CaO微胶囊后,NaCl水溶液中Cl-/OH-的浓度比显著降低,有利于提高钢筋的抗Cl-腐蚀能力。      

层层自组装多糖微胶囊的制备及其缓释型纯棉织物修饰应用

为制备生物相容性功能纺织材料,采用层层自组装技术将带有不同电荷的海藻酸钠(Alg)、壳聚糖(Chi)、透明质酸(HA)组装到碳酸钙模板上,利用乙二胺四乙酸(EDTA)去除模板,得到Alg/ Chi/ HA生物多糖微胶囊;利用超景深三维显微镜、扫描电子显微镜、红外光谱、综合热分析仪研究了微胶囊的形貌结构及热稳定性。结果表明:Alg/Chi/HA多糖微胶囊具有很好的中空结构及较强的稳定性;考察了多糖微胶囊吸附释放行为及其随pH值的变化规律,发现Alg/Chi/HA多糖微胶囊具有良好的pH值响应性;进一步将Alg/Chi/HA多糖微胶囊整理至棉纤维上,以制备缓释型功能纺织材料,为功能纺织品开发提供有益的实践经验与技术储备。     

蓄热调温织物低温防护过程的数值模拟

为提升普通织物的低温抵抗性能,将具有蓄热调温功能的相变微胶囊涂覆至织物表面制得蓄热调温织物,通过Fluent 软件对复合织物的低温防护过程进行模拟,在此基础上设置了蓄热调温织物的低温防护试验对模型的模拟精度进行检验,并模拟探究了微胶囊的相变潜热以及其在织物中所占的体积分数对蓄热调温织物低温防护性能的影响。结果表明:数值模拟结果可显示不同时间节点蓄热调温织物的温度场分布情况以及各区域的温度变化趋势,且试验结果与模拟结果的误差小于8.64%,该模拟结果可较为准确地再现蓄热调温织物的低温防护过程;当微胶囊的相变潜热由50 J/g增加至200 J/g时,织物的低温防护时间延长了70.1%;当微胶囊的质量分数由1%增加至5%时,织物的低温防护时间由214 s延长至388 s,同比提升了81.3%。     

芽菜腌制水微胶囊化制备技术的研究

利用微胶囊制备工艺探索芽菜腌制水利用新途径.通过单因素试酵母验确定了芽菜粉微胶囊最佳配方为芽菜腌制水350g、麦芽糊精20g、β-环状糊精10g.用正交试验优化了喷雾干燥工艺条件:在25MPa压力条件下均质处理,进风温度180℃,出风温度100℃,进料温度60℃,转速16000r/min.该微胶囊包埋工艺的优点是最大限度的保留了天然发酵芽菜特征酱香,而且微胶囊集粉率高,到达了87％,胶囊呈淡黄色,颗粒均匀,冲速溶性好理化指标及微生物指标均符合国家相关标准,实现了污染物“变废为宝”的目标.     

花生四烯酸微胶囊稳定性的对比研究

采用Schaat烘箱法对3种花生四烯酸粉末油脂进行稳定性研究。在整个试验过程中,每2天分别对3种样品的色泽、气味、溶解性感官评定,并测定3种花生四烯酸的过氧化值,对比它们的稳定性。结果表明:样品1的色泽、气味变化较慢,溶解性较好;样品3的色泽、气味变化较快,溶解性较差。样品1的稳定性较好,样品2的稳定性适中,样品3的稳定性较差。可以选用样品1和样品2添加到婴儿配方奶粉中对其稳定性和含量进行试验,以完成对乳粉中添加营养强化剂种类的确定。     

Microencapsulation of oil soluble polyaspartic acid ester and isophorone diisocyanate and their application in self-healing anticorrosive epoxy resin

Isocyanate and amine solution are microencapsulated, respectively, via in situ polymerization to realize the self-healing function in epoxy matrix. First, the isophorone diisocyanate (IPDI) microcapsules prepared with different core/shell ratios, emulsifier dosages and emulsification rates are characterized by field emission scanning electron microscope (FE-SEM). They exhibit integral spherical shape when the core/shell ratio is 3:1 and emulsifier concentration is 2.52 wt %, and the diameter of IPDI microcapsules ranged from 2.66 μm to 11.25 μm is manufactured by adjusting emulsification rate over the range of 3000–9000 rpm. Besides, during the microencapsulation of polyaspartic acid ester (PAE), urea, tung oil, as well as aqueous isocyanate are proposed to improve the stability of PAE emulsion. SEM and FTIR results reveal that aqueous isocyanate can react with partial PAE and form polyurea (PU) layer to take protection effectively. Further, IPDI-PAE dual microcapsules are incorporated into epoxy coatings, the self-healing and anticorrosion performance of coatings with various amounts of microcapsules are investigated systematically. It was found that the degree of repair and anticorrosion are increased with increasing microcapsules loading, and the appropriate amount of microcapsules addition is 15 wt %, which corresponding to 93% repair efficiency. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48478.     

Thermal performance investigation of a single medium temperature phase change microcapsule used for wind power absorption and heat storage system

Phase change microcapsules have a wide application in the heat storage system. The medium temperature heat storage systems such as medium temperature solar thermal plants, waste heat recovery systems and wind power absorption systems. In order to analyse the effects of configuration parameters and materials on phase change heat transfer process in a single medium temperature microcapsule, an enthalpy-transforming model was applied to trace the location of the solid-liquid interface and obtain the liquid fraction at different time in the melting process. Based on this model, the effects of particle size, the effects of wall thickness, the effects of wall materials and different medium temperature phase change materials were analyzed. The numerical results show that the larger particle size has a longer melting time, the melting time of 50 μm particle size and 250 μm particle size is 0.036 s and 2.48 s, respectively. In addition, the melting time of microcapsules with different wall thicknesses from the 1μm to 9μm is the same i.e., 0.14 s. Therefore, the wall thickness has little effect on the melting time of microcapsules. Besides, the microcapsule with the erythritol as inner material and the polystyrene as wall material has the longest melting time. Furthermore, the thermal conductivity of the wall materials is the main factor affecting the melting time. Moreover, the product of latent heat and density of phase change material is the main factor of the melting time.     

不同乳化剂作用下三聚氰胺-甲醛@正十八烷微胶囊相变复合材料微观形貌和热性能

采用原位聚合法,通过改变非离子/阴离子乳化剂组合制备了一系列以正十八烷(OD)为芯材、三聚氰胺(M)-甲醛树脂(F)为壁材的微胶囊相变储能材料,并借助FTIR、SEM、DSC和激光粒度分析仪等手段系统研究了乳化剂复配对M-F@OD微胶囊相变材料微观形貌和相变潜热的影响。结果表明,不同乳化剂组合及掺量对M-F@OD微胶囊相变材料的形貌和性能产生显著影响,当采用非离子和阴离子复合乳化剂时,M-F@OD微胶囊相变材料团聚现象得到明显改善,粒径分布更加均匀,颗粒尺寸进一步细化,粒径大小范围为0.1~1μm,储热能力明显提高,相变潜热达到70.86J/g。     

芳香微胶囊的制备及其在纺织品上应用的研究

用环氧树脂作为皮材制作芳香微胶囊,研究制备条件对其性能的影响,重点探讨了乳化剂、搅拌速度、温度等因素对微胶囊粒径的影响,并对微胶囊在纺织品上的固着工艺条件作了介绍．