小粒径咖啡因微胶囊制备及其缓释研究

本文研究了以明胶为囊材,采用反相乳化法制备咖啡因微胶囊,考察不同的制备条件对微胶囊粒径与微胶囊载药量、包埋率的影响。结果表明,乳化剂用量、水油比例和搅拌速度对微胶囊粒径有较大影响,加入苯甲酸钠能有效地提高微胶囊的载药量,提高明胶浓度可增加咖啡因的包埋率,且所得的微胶囊有一定的缓释性能。     

自修复微胶囊的制备及其影响因素研究

采用环氧树脂(E-51)和环氧小分子(SM80)为芯材、脲醛树脂为壁材,利用原位聚合法制备自修复微胶囊。采用光学显微镜(OM)观察了微胶囊的形成过程;采用扫描电子显微镜(SEM)考察了乳化剂种类对微胶囊微观形貌的影响;采用傅里叶红外光谱仪(FTIR)分析了微胶囊的化学成分;利用激光粒度仪分析了微胶囊的粒径分布;考察了不同乳化速度对微胶囊粒径分布的影响。试验结果表明:采用聚氧乙烯脱水山梨醇单油酸酯(吐温-80)作为乳化剂,其用量占芯材含量的3.0%,乳化转速为2000r/min时,制备的脲醛树脂微胶囊外形基本呈现球状,粒径分布较为均匀,红外分析表明已经成功制备了脲醛树脂微胶囊。     

新型保温建筑涂料用微胶囊乳液的制备

以三聚氰胺为壁材,空气(或二氧化碳气体)为芯材,采用锐孔法和乳化缩聚技术制备涂料用微胶囊乳液。以微胶囊的外形、粒径大小,微胶囊乳液稳定性、导热系数为评价指标,对涂料用微胶囊乳液制备方法、工艺条件进行了研究。结果表明:方法可行,工艺简便,经济;涂料用微胶囊乳液保温性能较佳。     

新型保温建筑涂料用微胶囊仿瓷乳液的制备

采用微胶囊技术制备空囊材料,以减少材料的导热性能,从而达到保温、节能降耗和提高材料性能的目的.以三聚氰胺为壁材,空气(或二氧化碳气体)为芯材,司盘-60为乳化剂,采用锐孔法和乳化缩聚技术制备涂料用微胶囊仿瓷乳液.以涂料用微胶囊的外形、粒径大小,涂料用微胶囊仿瓷乳液稳定性、导热系数为评价指标,对涂料用微胶囊仿瓷乳液制备方...     

艾叶提取物驱蚊微胶囊的制备

以天然驱蚊植物——艾叶提取物为芯材,采用复相乳液法制备驱蚊微胶囊。讨论了初乳中乳化剂用量、芯材与二氯甲烷体积比、壁材用量、保护性胶体浓度等对微胶囊粒径的影响,获得了最佳制备工艺。将粒径最小的微胶囊与黏合剂以一定比例混合后整理到涤纶织物上,并对驱蚊效果进行测试和分析。结果表明:最佳制备工艺为初乳中乳化剂体积分数为6%,芯材与二氯甲烷体积比为1∶6,壁材质量分数为4%,保护性胶体质量分数为2%;制得的微胶囊最小平均粒径为2.78μm;整理到涤纶织物上的驱蚊效果显著,蚊虫驱避率达到70%。     

用于自内冷溶液除湿的复配石蜡微胶囊的特性

以三聚氰胺?甲醛树脂为胶囊壁材、固液复配石蜡为胶囊芯材,采用原位聚合法制备了用于自内冷溶液除湿的相变材料微胶囊,研究了单一或不同类型乳化剂复配、乳化剂用量对相变材料微胶囊粒径、微观形貌及热性能的影响. 结果表明,非离子乳化剂NP-10与阴离子乳化剂SDBS复配所制微胶囊相变潜热较低,非离子乳化剂Span80和Tween80按质量比1:1复配、乳化剂占芯材质量的60%、乳化转速为1000 r/min时,所制微胶囊综合性能最佳,表面光滑致密,分散性良好,粒径均一,平均粒径为0.45 ?m,相变潜热为52.48 J/g,囊芯含量为58.44%,相变温度适用于以LiCl溶液为除湿剂的自内冷溶液除湿系统.     

茶树油/脲醛树脂缓释微胶囊的制备

以甲醛和尿素为微胶囊壁材原料,以茶树精油为芯材,采用原位聚合法制备茶树油/脲醛树脂微胶囊,能够弥补茶树油易挥发、易氧化和气味难闻的缺点。本文考察乳化剂的种类、乳化剂的用量、释放环境等因素对微胶囊的形貌、粒径、载药量以及缓释性能的影响。研究结果表明,以十二烷基硫酸钠为乳化剂,用量约为4%,固化时间为80min时,所得的载油微胶囊形状规则、外表圆滑、粒径均匀、平均约40~50μm,囊壁致密、壁厚约0.5μm。此外,载药量和缓释性能较好,本文研究制得的微胶囊载药量可达45%左右,4天释放量为68%左右,室温条件下微胶囊释放时长可达7天。     

壳聚糖季铵盐/维生素E微胶囊的制备工艺研究

采用复凝聚法制备壳聚糖季铵盐/维生素E微胶囊。通过可拍摄数码生物显微镜观察整个微胶囊制备过程的形态,研究反应过程的工艺条件对微胶囊乳液的影响,得到工艺制备的最佳条件是:以吐温-80和司班-80(1:1)作为乳化剂,用量为0.6%,壁材浓度为1.1%,芯壁比为1:1.5,乳化搅拌速度为2000 r min-1;复凝聚反应pH为5.2～5.4,时间为30 min;交联固化pH为5.8～6.0,时间为150 min。得到的微胶囊粒径在5~10μm,产品的载药量23.4%,包封率为85.0%。     

Study on preparation and sustained-release of sodium chloride-ethyl cellulose microcapsules

以乙基纤维素(EC)为壁材,NaCl为芯材,聚乙烯(PE)为添加剂,采用油相分离法制备了NaCl-EC微胶囊.最佳条件为:选用乙基含量为48％-49.5％,黏度为200cP的EC,浓度为2.4％.NaCl与EC的用量比为1:5,PE用量为0.45％,搅拌速率为450r·min-1,采用水浴缓慢降温方式.筛选出最佳工艺条件下制备的粒径在80～120目的微胶囊,研究了其在25℃下的释放性能.囊芯释放百分率以2.03％～56.47％之间,按零级动力学方程进行,64h后累计释放量为70.45％.     

NaCl-EC微胶囊的制备及缓释性能研究

以乙基纤维素(EC)为壁材,NaCl为芯材,聚乙烯(PE)为添加剂,采用油相分离法制备了NaCl-EC微胶囊。最佳条件为:选用乙基含量为48%~49.5%,黏度为200cP的EC,浓度为2.4%,NaCl与EC的用量比为1∶5,PE用量为0.45%,搅拌速率为450r.min-1,采用水浴缓慢降温方式。筛选出最佳工艺条件下制备的粒径在80~120目的微胶囊,研究了其在25℃下的释放性能。囊芯释放百分率以2.03%~56.47%之间,按零级动力学方程进行,64h后累计释放量为70.45%。     

响应曲面法优化水包油型天然松香乳液的制备

以天然马尾松松香为原料、ONIST APS-350为乳化剂采用常压转相法制备水包油（O/W）型天然松香乳液。考察了乳化剂用量、初始乳化温度、油水比（松香和水质量比,下同）与搅拌速度对O/W型天然松香乳液粒径分布的影响,并通过响应曲面法（RSM）对制备乳液的工艺参数进行模拟与优化。结果表明：制备O/W型天然松香乳液的最佳工艺条件为搅拌速度500 r/min、乳化剂用量9.95%、初始乳化温度112℃、油水比10：31,所得乳液平均粒径为131.1 nm,乳液离心稳定,静置3个月不分层,通过TEM表征发现,这种天然松香乳液颗粒具有核壳结构,其粒径大小与粒径仪测试结果一致。     

癸酸相变微胶囊的制备及热性能

以尿素、甲醛及癸酸为原料,利用原位聚合法制备了脲醛树脂包覆癸酸的相变微胶囊。以芯壁质量比、乳化剂用量、乳化转速及固化剂含量为变量设计正交实验,采用ESEM、FTIR和DSC分别表征癸酸微胶囊的微观形貌、化学结构及热性能,利用渗漏率实验测试癸酸微胶囊的防渗性能。结果表明,m(OP-10)∶m(Span-80)=4∶1的复合乳化剂有利于改善癸酸微胶囊颗粒特性。癸酸微胶囊P(芯壁质量比3∶2、乳化剂用量占芯材质量5%、乳化转速1400 r/min、固化剂间苯二酚用量占尿素质量12%)在微观形貌上分散良好且大小均一,相变潜热为123.91 J/g,渗漏率和包覆率分别为6.95%和69.7%,与癸酸微胶囊S(芯壁质量比1∶1、乳化剂用量占芯材质量6%、乳化转速1100 r/min、固化剂用量占尿素质量10%)相比,癸酸微胶囊P的渗漏率降低了57.2%,包覆率反而提高了132.3%,具有良好的热性能。     

乙二胺四乙酸四钠盐缓释微胶囊的制备与表征

The microcapsules with cores of ethylenediamine tetraacetic acid tetrasodium salt (Na4-EDTA) and walls of polyurea were synthesized via an interfacial polycondensation reaction with 2,4-tolylene diisocyanate as an oil-soluble monomer and diethyl triamine as a water-soluble monomer. Various manufacturing parameters, including the amount of emulsifier, agitation speed, stirring time and ratios of the wall materials to core materials, were altered to optimize process variables during the synthesis of microcap-sules, and the effects of these parameters on the characteristics of the microcapsules were examined. The structure, morphology, mean particle size and size distribution were characterized by optical microscope and scanning electron microscopy (SEM), showing that the mean diameter of optimal microspheres was approximately 6 μm, and microcapsules were spherical. In vitro release of Na4-EDTA from these microcapsules was performed in distilled water. Under the optimal preparation conditions, the Na4-EDTA re-lease profiles were biphasic with a burst release followed by a gradual release phase. After an initial burst, a continuous Na4-EDTA release was up to 5-7 days. The optimal synthesis conditions for the microcapsules with stable, good morphology and good con-trolled-release properties were as follows: emulsifier Span-80 10% (by mass), agitation speed 900 r&;#8226;min－1, stirring time 30 min, and the ratio of the wall materials to core materials 0.15.     

具有良好稳定性的石蜡乳液的制备及改进

选用Span80、Tween80为石蜡复配乳化剂,采用O-D乳化法与PIT法相结合研究了乳化剂HLB值、乳化剂用量、乳化水加入方式及用量、乳化时间、乳化温度、搅拌方式及搅拌速度对石蜡乳液制备的影响。结果表明,适宜的乳化工艺条件为:复合乳化剂的HLB为10.5,复合乳化剂的用量(M乳化剂/M石蜡)为30%,乳化水用量(M水/M石蜡)为2.5,乳化时间30 min,乳化温度75℃,搅拌速度1 000 r/min。在该条件下可制得具有良好稳定性和分散性的石蜡乳液,粒径单分散性也较好。     

影响高固含量石蜡乳液颗粒度因素的考察

以58#石蜡为原料,非离子与阴离子表面活性剂复配物为乳化剂,考察了乳化剂的HLB(亲水亲油平衡)值、乳化剂用量、乳化温度、乳化时间、搅拌速度和乳化方法等工艺条件对石蜡乳液颗粒度的影响.结果表明,石蜡乳化剂适宜的HLB值约为9.3,乳化剂的用量、乳化温度、乳化时间、搅拌速度和乳化方法对乳液的粒度均有影响.w(乳化剂)=7%,乳化温度85℃～90℃,乳化时间40 min,搅拌速度为1 000 r/min下采用剂在油中法,制得了平均粒度为1.3 μm,折光率为1.42,固含量约为50%的石蜡乳液,乳液外观为均匀、细腻的乳白色液体.     

Preparation and properties of phase‐change heat‐storage UV curable polyurethane acrylate coating

Phase‐change heat‐storage UV curable polyurethane acrylate (PUA) coating was prepared by applying microencapsulated phase change materials (microPCMs) to PUA coating. MicroPCMs containing paraffin core with melamine‐formaldehyde shell were synthesized by in situ polymerization. The effect of stirring speed, emulsification time, emulsifier amount, and core/shell mass ratio on particle size, morphology, and phase change properties of the microPCMs was studied by using laser particle size analyzer, Fourier transform infrared spectroscopy, X‐ray photoelectron spectroscopic analysis, scanning electron microscopy, and differential scanning calorimetry. The results showed that the diameter of the microcapsules decreased with the increase of stirring speed, emulsification time, and emulsifier amount. When the mass ratio of emulsifier to paraffin is 6%, microcapsules fabricated with a core/shell ratio of 75/25 have a compact surface and a mean particle size of 30 μm. The sample made under the above conditions has a higher efficiency of microencapsulation than other samples and was applied to PUA coating. The dispersion of microPCMs in coating and heat‐storage properties of the coating were investigated. The results illustrated that the phase‐change heat‐storage UV curable PUA coating can store energy and insulate heat. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41266.     

聚砜包覆双环戊二烯微胶囊的制备

采用简单易控的溶剂挥发法成功制备了聚砜包覆双环戊二烯微胶囊,讨论了反应温度、分散剂、芯壁比及搅拌速度对微胶囊性能的影响,并通过扫描电子显微镜、光学显微镜和热重分析仪对微胶囊的表面结构、形貌和热性能进行了研究。结果表明,选择明胶溶液作为分散剂,反应温度为30 ℃时,可制备出粒径和壁厚可控的具有规则球形的微胶囊;随着芯材比例的增大,微胶囊壁厚减小;粒径随着搅拌速度的加快而减小。     

In situ polymerization of uniform poly(urea–formaldehyde) microcapsules containing paraffins under the high-speed agitation without emulsifier

In this paper, uniform spherical poly(urea–formaldehyde) (PUF) microcapsules containing paraffins, which can be used as phase change materials for energy storage, were prepared by in situ polymerization method under high-speed agitation (≥10,000?rpm) without emulsifier. The influence of high-speed agitation on particle size of as-prepared microcapsules and the tightness of microcapsules were also investigated. The results show that, all the microcapsules have <10?μm mean particles-size and narrow-size distribution, and the mean particle size decreases with the increase of agitation rate. Furthermore, when the agitation rate is >16,000?rpm, the effectiveness of reducing particle size by high-speed stirring is not as remarkable as that of lower speed agitation. In order to gain good tightness of PUF microcapsules under the high-speed agitation conditions, the final pH value of reaction solution should be lower down compared with that of conventional agitation. In our investigation, when the agitation rate was 10,000?rpm, microcapsules fabricated at pH value <2.0 were sealed and own good tightness, however, those fabricated at pH value >2.2 were not sealed.     

溶剂挥发法制备聚砜包覆桐油自修复微胶囊

以聚砜为壁材,桐油为芯材,采用溶剂挥发法制备了聚砜（PSF）包覆桐油自修复微胶囊。考查了不同种类的分散剂、搅拌速度、芯壁比（芯材与壁材的质量比）等工艺参数对微胶囊性能的影响,通过扫描电子显微镜、光学显微镜和热重分析仪等对微胶囊的表观形貌、粒径、壁厚、包覆率和热稳定性能等进行表征。采用所合成的微胶囊制备了环氧树脂基防腐蚀涂层,并对其防腐蚀性能进行了评价。结果表明,30 ℃时,以明胶/聚乙烯醇复配体系作为分散剂,芯材与壁材质量比为1.3:1,搅拌速度为700 r/min时制备出的微胶囊表面光滑致密,粒径在130 μm左右,热稳定温度为350 ℃;盐雾实验结果表明,所制备的微胶囊自修复涂层具有良好的防腐蚀性能。     

分散染料微胶囊粒径及其分布的影响因素

采用原位聚合法对分散染料进行微胶囊化,芯壁比、剪切乳化速率、反应搅拌速度、系统调节剂MS用量、单双层滴加单体时间都将对分散染料微胶囊的粒径大小和分布产生重要影响。