首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到18条相似文献,搜索用时 171 毫秒
1.
以6%的琼脂糖溶液为水相,不同体积配比的液体石蜡(LP)和石油醚(PE)的混合溶液为油相,PO-5S为乳化剂,采用微孔膜乳化法制备了平均粒径为90 mm的琼脂糖微球. 考察了SPG膜孔大小、油相组成、反应温度、压力等因素对成球粒径及其分布的影响. 结果表明,在使用膜孔为25.9 mm的微孔膜、LP/PE体积比为11:1及65℃的条件下可制得均一的大粒径琼脂糖微球,微球平均粒径为93.3 mm,粒度分布系数为1.25,且各批产品的相对标准偏差仅为1.34%,产品重复性良好.  相似文献   

2.
T型微通道装置制备尺寸均一壳聚糖微球   总被引:8,自引:1,他引:7  
采用T型微通道装置制备尺寸均一的壳聚糖微球. 研究了乳化剂用量、油水两相流速比和流速等条件对乳液粒径的影响,尝试制备了不同分子量的壳聚糖乳液,并确定了交联固化方式. T型微通道装置的油相通道直径350 mm,水相通道直径65 mm,两通道接口处直径16 mm. 以1.5%(w)的壳聚糖醋酸水溶液为水相,以液体石蜡/石油醚(7/5, j)的混合物作为油相,水相流速20 mL/min,油水两相流速比为15:1,4%(w)的PO-500作为油相乳化剂,制备得到的壳聚糖乳液粒径分布系数<10%. 以戊二醛的甲苯溶液作为交联剂,当戊二醛所含醛基与壳聚糖所含氨基的摩尔比为1:1时,交联时间选择2 h.  相似文献   

3.
为提高魔芋的利用率,开发了环保型木材胶粘剂。以魔芋葡苷聚糖(KGM)为基体、壳聚糖(CS)为改性剂,制备了KGM-CS共混胶粘剂。采用单因素试验法和正交试验法优选出制备该胶粘剂的最佳工艺条件。研究结果表明:当w(KGM)=w(CS)=2.5%(相对于KGM-CS共混胶粘剂质量而言)、热压温度为130℃、热压时间为15 min和热压压力为4 MPa时,KGM-CS共混胶粘剂的综合性能相对最好,由其压制而成的胶合板之干态、湿态胶接强度分别为3.04、1.80 MPa。  相似文献   

4.
采用快速膜乳化技术结合溶剂蒸发法制备以生物可降解聚乳酸-羟基乙酸(PLGA)为载体的胸腺法新载药微球,考察了PLGA分子量、油相中PLGA和乳化剂浓度、外水相pH值和内水相体积等对微球包埋率和粒径的影响. 结果表明,制备粒径均一的PLGA载药微球的优化条件为:PLGA分子量51 kDa,油相中PLGA和乳化剂浓度为100和10 g/L,内水相体积0.5 mL,外水相pH值为3.5. 该条件下所制载药微球粒径均一性好(Span<0.7),药物包埋率高达80%以上,突释率24 h内低于20%,线性持续稳定释药时间长达30 d.  相似文献   

5.
乙酸酐对魔芋葡甘聚糖的改性   总被引:3,自引:0,他引:3  
光善仪  宫晓梅  高晓燕  徐洪耀 《精细化工》2004,21(7):529-531,543
研究了乙酸酐对魔芋葡甘聚糖的改性,制备了魔芋葡甘聚糖醋酸酯,优化了制备工艺条件,得出了酸性催化剂条件下,乙酰化魔芋葡甘聚糖的最佳改性工艺条件为:n(乙酸酐)∶n(魔芋葡甘聚糖)=4 8∶1,反应温度50℃,反应时间4h,催化剂c(H2SO4)=0 038mol/L,取代度DS=0 662。物化性能测试表明,取代度超过0 270时,魔芋葡甘聚糖醋酸酯在水中溶解;60℃时最大溶解度为w(魔芋葡甘聚糖醋酸酯)=12%,取代度超过0 469时,魔芋葡甘聚糖醋酸酯能制成均匀的薄膜,膜厚10~30μm。  相似文献   

6.
李先红  林晓艳  罗学刚  黄波 《化工学报》2012,63(5):1630-1636
以资源丰富的天然可降解高分子材料魔芋葡甘聚糖(KGM)为原料, 以甲基丙烯酸甲酯和丙烯酸甲酯为单体,过硫酸铵为引发剂,合成了热塑性魔芋葡甘聚糖。将热塑性魔芋葡甘聚糖(TDKGM)和聚己内酯(PCL)熔融共混制备热塑性魔芋葡甘聚糖/聚己内酯共混物(TDKGM/PCL)。通过热重分析、扫描电镜、差示扫描量热仪(DSC)、XRD和万能力学试验机等对TDKGM/PCL共混物的结构和性能进行了分析表征。结果表明:共混物中热塑性魔芋葡甘聚糖对聚己内酯的结晶起到了成核剂的作用,使聚己内酯能在较高温度下开始结晶,并可明显提高共混物中聚己内酯相的结晶速度。TDKGM/PCL复合材料(20/80)的最大扭矩值为48.7 N·m,塑化时间在300 s以上,平衡扭矩在10.7 N·m,与PE相当接近,并且具有高达256.48%的断裂伸长率。  相似文献   

7.
宋进  徐航  邹威  王洪  张晨 《中国塑料》2022,36(7):8-13
以浓乳液作为悬浮聚合的油相,采用水(W)/油(O)/W浓乳液/悬浮聚合方法制备出了内部具有通孔结构、粒径均一的聚甲基丙烯酸叔丁酯多孔微球。结果表明,通过研究乳化剂含量、搅拌速度等参数对多孔微球的内部微孔形貌与微球粒径的影响,发现当乳化剂含量为4 %时,得到的聚合物微球内的微孔结构分布均匀;而聚合物微球的平均粒径会随着搅拌速度的增大而减小。将不同粒径的多孔微球进行酸化水解后得到了表面羧基官能化的聚合物多孔微球,利用其丰富的通孔结构实现了对铜离子(Cu2+)的有效吸附,当微球平均粒径介于200~300 μm时,铜离子的去除率最高,可达99.3 %。  相似文献   

8.
低温可逆热敏示温微胶囊的粒径控制及结构   总被引:2,自引:0,他引:2  
采用界面聚合法制备了以CoCl2为芯材、聚乙烯醇为壁材的可逆热敏示温微胶囊,系统研究了乳化剂用量、内水相与油相用量比、搅拌速度、内乳液加入方式对微胶囊粒径的影响,并对微胶囊的结构和形貌进行了表征. 结果表明,当Span-80/Tween-80含量为5%(w)、水油体积比为0.2、转速为1200 r/min、内乳液采用逐步滴加方式加入外水相中时,制备的微胶囊粒径均一,平均粒径为12 mm,分散性好.  相似文献   

9.
采用快速膜乳化技术,以大豆油为油相、葡萄糖为固化剂,制备均一载硫酸亚铁明胶微球,考察了制备参数对明胶微球形貌和均一性的影响. 结果表明,优化的制备参数为明胶溶液浓度0.200 g/mL、乳化剂浓度0.07 g/mL、初乳均质转速10000 r/min、固化反应时间20 min. 在该条件下制备了球形圆整、平均粒径为50 μm的均一载FeSO4明胶微球,FeSO4包埋率达44.12%,Fe2+含量为60.8%.  相似文献   

10.
使用复配乳化剂,以液态烷烃为连续相,丙烯酰胺溶液为分散相制备均匀的油包水(W/O)型微乳液。通过测定体系电导率及观察稳定性,以水相的最大增溶度为指标,研究了连续相的种类、乳化剂复配、丙烯酰胺(AM)单体浓度、电解质浓度对微乳液体系稳定性的影响。结果表明:以异构烷烃Isopar M为连续相,乳化剂Span80/OP-10复配且当复配乳化剂中Span80含量占80%时,体系对水相增溶量最大;提高AM浓度、加入适量电解质Na Ac,都会增强微乳液的稳定性;电解质的加入还会提高乳化剂的最佳HLB值。  相似文献   

11.
采用反相细乳液法,以白油为连续相,失水山梨醇单油酸酯/聚氧乙烯失水山梨醇单油酸酯为乳化剂,一种聚合物型乳化剂(聚异丁烯琥珀酸酯与山梨醇油酸酯的混合物)作为助稳定剂,通过正交实验确立了基本乳液体系,考察了微乳化工艺中转速变化、乳化剂体系组成、浓度及单体含量对聚合产物稳定性的影响,并研究了不同单体浓度和聚合时间等聚合工艺对微球粒径及分布的影响。结果表明,复合乳化剂含量为3.0%,转速为10 000 r/min下乳化20 min,在单体浓度55%,亲水疏水平衡值(HLB值)为5.5,采用氧化还原引发体系,聚合时间为6 h时,可以得到固含量35%以上、粒径数百纳米的长期稳定的亚微米级聚丙烯酰胺微球乳液。  相似文献   

12.
Oil-containing poly(vinyl alcohol) (PVA) microcapsules in the size range of 5–20 μm were prepared by the simple coacervation of PVA followed by chemical crosslinking of the coacervated PVA membrane with glutaraldehyde. Coacervation of the aqueous polymer solution was achieved by the addition of a phase separation inducer (e.g., sodium sulfate). PVA of different grades (e.g., molecular weight and degree of hydrolysis) was utilized both as stabilizer and wall-forming material. Dispersion of the oil phase in the aqueous PVA solution was effected by a homogenizer. The effects of the various process parameters, such as the agitation speed, the type and concentration of PVA, the volume ratio of the internal oil phase to the external aqueous phase, the viscosity of the oil phase as well as the electrolyte concentration in the aqueous solution, on the stability and the size distribution of the emulsion droplets and microcapsules were experimentally investigated. It was shown that high agitation rates and low interfacial tension (e.g., high PVA concentrations) resulted in a significant reduction of the size of the emulsion droplets and microcapsules. On the other hand, as the viscosity and the amount of the dispersed oil phase increased, the capsule size increased. Finally, it was found that the concentration of the electrolyte significantly affected the stability of the (o/w) emulsion, the size and concentration of coacervated PVA colloidal aggregates, as well as the morphology of the polymer wall membrane formed by the adsorption of the polymer-rich phase to the oil/water interface. © 1996 John Wiley & Sons, Inc.  相似文献   

13.
以煤油为油相,丙烯酸钠水溶液为水相,自制的非离子聚合型乳化剂-Span80丙烯酸酯(Span80AA)、Span80和Twen80组成复合乳化剂,制备反相乳液。计算出Span80AA的HLB值,考察了乳化剂浓度、水相体积分数Φ及单体浓度对乳液类型及稳定性的影响。结果表明:HLB(Span80AA)=2.709;Span80AA、Span80和Twen80的最佳质量比为0.8∶0.3∶0.1。形成稳定的反相乳液理想条件是:复合乳化剂质量分数为6%~8%;Φ<57%;单体浓度为2.0~3.5 mol/L。  相似文献   

14.
Functional poly(ester-anhydride) microspheres were prepared using emulsion solvent evaporation (ESE) and phase inversion methods (PIM). The poly(ester-anhydride)s were obtained by polycondensation of sebacic acid (SBA) and oligo(3-allyloxy-1,2-propylene succinate) terminated with carboxyl groups (OSAGE). The effects of various parameters, including: polymer and emulsifier concentrations, stirring speed and molecular weight of polyvinyl alcohol (PVA) used as emulsifier on size, size distribution and morphology of microspheres obtained by ESE technique were examined. The size of microspheres obtained was in the range 2–30 µm and depended mainly on the stirring rate in emulsion formulation process, as well as concentration of polymer solution used. Molecular weight of PVA, and its concentration in aqueous phase, significantly influenced tendency to agglomeration of microparticles formed, but only slightly changed the size of microspheres. The present study demonstrated that the ESE method can be useful to formulate, from functional poly(ester-anhydride)s, small (2–3 µm) or large (20–30 µm) microspheres with relatively narrow size distribution. Such microspheres were loaded with three model compounds (rhodamine B, p-nitroaniline, and piroxicam) with different water solubility and their release characteristics were examined. In the present study microparticles were also obtained by alternative phase inversion method to compare mainly stability of polymers during formulation of microspheres by both techniques.  相似文献   

15.
采用1,4-二氨基蒽醌作为发色体,与异佛尔酮二异氰酸酯反应生成紫色预聚物,与聚乙二醇600通过界面聚合法制备了氨基蒽醌紫色聚氨酯微球。考察了乳化剂种类、用量、乳化速度、发色体用量对微球粒径的影响。结果表明:与聚氧乙烯辛基苯酚醚-10、失水山梨醇单油酸酯聚氧乙烯醚(Tween80)和失水山梨糖醇单油酸酯(Span80)相比,十二烷基苯磺酸钠(SDBS)乳化剂更适合用于聚氨酯球的制备。SDBS质量分数3.5%(以油相为基准)的粒径分布最窄,微球粒径在350nm左右。微球平均粒径随乳化速度增大而减小,在8000r/min粒径分布最集中。发色体在壳层体系中加入量为1mmol时粒径分布系数最小,平均粒径在500nm。通过SEM和TEM表征,结果显示:聚氨酯微球粒径在500nm左右,表面光滑的球形,内部呈空心结构。氨基蒽醌聚氨酯紫色微球印花织物颜色性能优异,且具有较高色牢度。  相似文献   

16.
Spherical hollow alumina powders (alumina microshells) were prepared from evaporation of water-in-oil (w/o) type emulsions by employing an aqueous Al(NO3)3 solution as water, mineral oil as the organic phase and a non-ionic surfactant, Arlacel 83, as the emulsifier. It was found that 65% mineral oil, 30% aqueous Al(NO3)3 and 5% Arlacel 83 composition produced stable, w/o type emulsions by mechanical stirring at 20°C. The aluminum ion concentration was varied between 0·25 and 2·0 to investigate its effect on the emulsion droplet size. Alumina microshells obtained from the evaporation of w/o emulsions were characterized with respect to size and distribution. The influence of aluminum ion concentration on these properties was also studied.  相似文献   

17.
Poly(lactic‐co‐glycolic acid) (PLGA) microspheres prepared using a traditional solvent evaporation or double emulsification method are usually polydisperse with an uncontrollable particle size distribution, which brings about poor application performance. In our research, monodisperse magnetic PLGA microspheres were prepared using a microchannel device based on a water‐in‐oil‐in‐water composite emulsion. The composite emulsion was formed by injecting a dichloromethane–gelatin water‐in‐oil emulsion into a microchannel together with an external water phase, i.e. poly(vinyl alcohol) (PVA) aqueous solution. Mean particle size control of the microspheres was executed using the osmotic pressure difference between internal and external aqueous phases caused by regulating NaCl concentration in PVA aqueous phase. It is found that monodisperse magnetic PLGA microspheres with high magnetic responsiveness can be successfully prepared combining the microchannel device with composite emulsion method. Mean particle size of the microspheres with coefficient of variation value below 4.72% is controllable from 123 to 203 µm depending on the osmotic pressure. The resulting samples have pyknotic and smooth surfaces, as well as spherical appearance. These monodisperse magnetic PLGA microspheres with good superparamagnetism and magnetic mobility have potential use as drug carriers for uniform release and magnetic targeting hyperthermia in biological fields. © 2015 Society of Chemical Industry  相似文献   

18.
用二次乳化法制备一种油包水型上光蜡乳液的研究   总被引:1,自引:0,他引:1  
二次乳化法制备的上光蜡乳液是由连续相和非连续相组成,连续相是由有机溶剂,有机硅氧烷和油包水型乳化剂构成的油相,其非连续相的组成形式是包含微小的蜡粒子的水粒子均匀分散在连续的油相中。这种制备方法是,在室温下,将水包油型乳化蜡加入并均匀分散到含有有机硅氧烷和油包水型乳化剂的有机溶剂中。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号