乳液模板法制备新型pH响应微胶囊材料的研究

利用乳液模板法制备了新型微胶囊材料。以小麦水解蛋白为稳定剂，水为外相、辛癸酸甘油酯为内相，制备了水包油型Pickering乳液。通过显微镜和粒径统计表征了乳液的微观结构，稳定剂质量分数为1%、2%、3%、4%和5%的Pickering乳液平均液滴直径分别为96.8μm、78.2μm、62.31μm、47.6μm和38.7μm。加入戊二醛与蛋白的氨基发生席夫碱反应，交联界面相形成微胶囊，通过红外光谱、显微镜和EDS Mapping证实了微胶囊的形成。戊二醛浓度为5%、10%、20%、30%、40%和50%时，微胶囊产率分别为75.9%、52.9%、35.3%、41.7%、39.0%和38.2%。由于席夫碱的亚胺基团具有pH响应性，可在酸性条件下断裂，故而该微胶囊具有pH响应性，能够在1mol/L盐酸环境下发生结构破裂，达到控制释放内部包封的油溶性组分的目的。     

毫米级水溶性芯材胶囊的微流控制备方法研究

为开发水溶性芯材胶囊制备新技术,基于微/毫流控技术设计了一种三维结构流动聚焦微通道芯片,采用该芯片制备了水包油包水(W/O/W)型双重乳液,以特种改性环氧丙烯酸酯为中间相,通过在线光固化方式进行中间相的固化,从而制备出粒径均一、颗粒圆整、包封率高的毫米级水溶性芯材胶囊,并研究了流速等因素对乳液形成过程、乳液粒径的影响。当三相流速分别为10mL/h、12mL/h、110mL/h时,所制备的微胶囊平均粒径为2.02mm,分散度小于3%。微/毫流控技术具有较好的稳定性和可操控性,实验装置具有易安装、易拆卸、便于清洗及可重复多次利用等优点。选用绿色环保、高效的光固化方式实现了胶囊壁的快速固化和高效封装。微/毫流控技术设备简单、容易操作,速度快、通量高,溶剂浪费少,达到节能降耗和环境保护的目的,适用于工业推广。     

利用SPG膜制备O/W型乳液实验研究

利用孔径为0.6μm的SPG(Shirasu Porous Glass)多孔微滤膜,以异辛烷为分散相、pH=7的磷酸盐缓冲水溶液为连续相、以SDS(十二烷基硫酸钠)和PVA(聚乙烯醇)分别为水相乳化剂和稳定剂,制备了O/W型乳液,研究了操作条件对乳液性能包括液滴大小及分布的影响关系.当跨膜压差在0.12~0.16 MPa时,连续相流速分布在0.20~0.40 m/s时,乳化剂浓度在其临界胶束浓度(CMC)之上时,乳液的单分散性较好.由于乳液具有良好的稳定性和单分散性,可用于多相界面酶催化反应.     

W/O/W复乳体系制备聚合物微胶囊的影响因素分析

总结了近年来W/O/W复乳体系制备微胶囊和提高W/O/W型复乳液稳定性的研究进展,重点分析了W/O/W复乳体系制备聚合物微胶囊的影响因素,主要有W/O初乳的稳定性,壁材,外水相,复乳的乳化条件和囊壁固化条件。对微胶囊形貌的改善、包覆率的提高及粒径分布的控制将起到积极作用。     

利用双重乳液法制备蜂窝状聚砜空心微球

通过W/O/W型双重乳液法制备蜂窝状聚砜(PSF)空心微球。研究了油相表面活性剂的类型、油水比及准备温度的影响。结果表明,油相表面活性剂的类型是决定PSF微球形貌的主要因素;第二次乳化的油水比影响微球的形成;准备温度能有效地控制微球表面孔的多少。     

液体石蜡乳液制备及其性能研究

利用高速搅拌和超声乳化法,制备了液体石蜡乳液。研究了表面活性剂的组成、用量和温度等因素对乳液性能的影响。结果表明:添加0.5%的油酸钠和十六烷基三甲基溴化铵混合表面活性剂制备的乳液为O/W型,乳液久置不分层,稀释分散性为一级,无漂油现象,稳定性良好。乳液的表面张力平均值为24.50mN/m,D50平均粒径为1.56μm。     

含固相淀粉的反相乳液体系稳定性研究

以液体石蜡为油相,烯类单体的水溶液为水相,Span80和OP-4为复配乳化剂制备反相乳液.考察了乳化剂HLB值及浓度、水相体积分数Φ、单体用量及固相淀粉颗粒对乳液类型及稳定性的影响规律.实验结果显示:乳化剂HLB值对乳液类型及稳定性影响显著,在HLB=4.3～6.1范围内,能形成稳定的油包水(W/O)型乳液;乳化剂最佳质量分数为5%～8%;Φ应小于50%;单体将导致反相乳液稳定性降低;固体淀粉的存在有利于形成W/O型反相乳液,并且能使反相乳液体系的稳定性明显提高.     

丙烯酸丁酯-苯乙烯共聚乳液型吸油树脂的合成及性能研究

以丙烯酸丁酯(BA)和苯乙烯(St)为单体,二乙烯基苯(DVB)为化学交联剂,采用乳液合成法制备吸油树脂.通过正交实验得到最佳合成配方,即BA∶ St=2∶1,w(二乙烯苯)=2％,w(过硫酸钾)=1％,w(丁苯橡胶)=O％,二甲苯的吸收率达到8.73g/g.同时探索了单体配比、DVB用量、油品种类对树脂吸油性能的影响...     

甜玉米芯多糖纳米乳微胶囊制备及释放

目的 改善甜玉米芯多糖(SCP)大分子特性以及稳定性,促进SCP的肠道吸收。方法 将SCP水溶液制备成油包水型(W/O)甜玉米芯多糖纳米乳液(SCP-NE),以复合蛋白为壁材制备成SCP-NE微胶囊,采用单因素试验、Box-Behnken设计和响应面法优化SCP-NE微胶囊制备工艺,以粒径分析、红外光谱分析、热重分析,对SCP-NE微胶囊物化性质进行研究,并进行体外模拟胃肠液释放研究。结果 制备SCP-NE微胶囊最佳条件为麦芽糊精(MD)与大豆分离蛋白(SPI)的质量比为2∶3、芯壁比为1∶2、总体固形物含量为20%,此时包封率达到(87.6±1.3)%。体外模拟胃肠液释放结果表明,SCP-NE微胶囊在2 h的胃液消化中释放率为8.83%,在模拟肠液中1 h的释放量为62.87%。结论 以MD和SPI作为壁材制备的SCP-NE微胶囊在胃肠液释放中具有良好的缓释性能。     

电导法对CTAB/正丁醇/环己烷/水四组分微乳体系的研究

利用电导率(K)-增溶水量(ml)关系曲线研究了CTAB/正丁醇/环己烷/水四组分微乳体系在不同增溶水量时的3种结构,即油包水(W/O)、油水双连续(B.C.)、水包油(O/W).讨论了表面活性剂CTAB与助表面活性剂正丁醇不同浓度时对微乳液稳定性的影响,得出了微乳液稳定时CTAB和正丁醇的合适配比.     

Preparation of TiO2 hollow microparticles by spraying water droplets into an organic solution of titanium tetraisopropoxide

Hollow, spherical TiO₂ microparticles several tens of micrometers in diameter were prepared by spraying water into an organic phase containing titanium tetraisopropoxide (TTIP) as a titanium source. The rapid hydrolysis of TTIP at the water-oil interface resulted in the formation of a TiO₂ shell covering the water droplet. Hexane and cyclohexane were better solvents than isopropanol for fabricating hollow spherical microparticles, suggesting the importance of immiscibility of the solvent with water in this synthesis method. The average particle size increased as the distance from the nozzle to the surface of the TTIP solution was increased. The shell thickness was reduced by the addition of ethanol to the sprayed water droplet. These results demonstrate the controllability of the structure of TiO₂ hollow microparticles, including the diameter and the shell thickness.     

水加入量对全水聚氨酯泡沫塑料性质的影响

分析了以水为发泡剂的全水聚氨酯发泡成型工艺过程中水的加入量对泡沫塑料性质的影响。研究了异氰酸酯指数为105,聚醚多元醇官能度为4,羟值为480mgKOH/g时,发泡剂水加入量与泡沫塑料开孔率、力学性能、泡沫稳定性等性质的关系。结果表明,聚氨酯泡沫塑料随着水的加入量从1g增加到10g,泡沫体拉伸强度降低了30%,压缩强度降低了29%;泡孔直径由50μm～100μm增加到300μm～400μm;玻璃化转变温度由102℃上升到112℃。     

Simple fabrication of hollow poly-lactic acid microspheres using uniform microbubbles as templates

A simple method was developed that uses microbubbles as templates to fabricate hollow microspheres covered with a biodegradable polymer. By stably keeping microbubbles with the diameter of about 2 µm inside a solvent droplet dissolving a biodegradable polymer and then slowly drying the solvent, hollow microspheres that had an average inner diameter of about 2 µm and a shell thickness of about 500 nm were obtained. This simple method was successfully used to easily fabricate uniform hollow microspheres covered with poly-lactic acid (PLA) by using uniform 2-µm-diameter bubbles as templates.     

O/W/O多重乳液法制备毫米级氧化铝空心球

采用O/W/O多重乳液法, 以液体石蜡为内核, 氧化铝溶胶为外壳层组成的复合液滴作为前驱体, 制备毫米级氧化铝空心球, 研究了装置几何结构对前驱体的形成和固化过程对空心球结构的影响。结果表明, 内部油相通过直流通道直接注射到水相液滴内部时, 形成的复合液滴具有均一核壳结构, 壁厚和直径在30~80 μm和800~2200 μm可控。液滴置于水平方向旋转固化, 保持转速在20~60 r/min, 所得凝胶球可以保持完整的球形度和核壳结构。1200℃高温煅烧制备出的氧化铝空心微球维持高的球形度和空心结构, 表面粗糙度大约22 nm, 壁厚达到几十微米, 直径达到毫米级, 主要晶型为稳定的α-Al₂O₃。     

Polyurethane foam containing microencapsulated phase-change materials with styrene–divinybenzene co-polymer shells

Polyurethane (PU) foam containing phase change materials is a kind of new heat-insulating material which can store and release heat energy. The microencapsulated n-octadecane (MicroPCMs) with a styrene (St)–divinybenzene (DVB) co-polymer shell was synthesized by means of suspension-like polymerization. The surface morphology, diameter, enthalpy, and thermal stability were investigated by using scanning electronic microscope (SEM), differential scanning calorimeter (DSC), and TGA. The average diameter of the microcapsules is about 80 μm. The enthalpy of the microcapsule is about 126 J/g. PU foams containing MicroPCMs were fabricated by adding the MicroPCMs in reactants. MicroPCMs are evenly inserted inside the foam and the enthalpy of the foam rises with the increase of the content of microcapsules. The enthalpy is about 24 J/g for the foam containing 26.8 wt% MicroPCMs.     

多壁碳纳米管/聚偏氟乙烯共混中空纤维膜的制备及表征

采用非溶剂致相分离(NIPS)法,添加羧基化多壁碳纳米管(MWCNTs-COOH)制备聚偏氟乙烯(PVDF)中空纤维超滤膜,研究了MWCNTs-COOH的添加量、管径对超滤膜性能的影响。通过扫描电镜、傅里叶红外光谱仪、X射线衍射仪分别研究了膜的形态、结构、晶型变化。结果表明,在MWCNTs-COOH质量分数为0.03%,管径为20~30nm时,中空纤维膜纯水通量、对牛血清蛋白(BSA)截留率、亲水性、抗污染性能达到最大。膜的拉伸强度、断裂伸长率相比纯PVDF膜显著提高,随MWCNTs-COOH添加量增加,先增大后减小且在0.03%达到最大;但随管径增大而减小。结果显示,质量分数0.03%,管径为20~30nm的MWCNTs-COOH制备出的中空纤维膜性能最优。     

Fabrication of polystyrene hollow spheres in W/O/W multiple emulsions

One mild multiple emulsions was used for the fabrication of hollow polystyrene (PS) spheres. Polystyrene was dissolved in a volatile organic solvent to form the O phase, then an aqueous phase containing a surfactant was transferred into above phase to form an oil-in-water (W_in/O) emulsion, followed by addition of W_in/O emulsion in the external W_out phase, and solvent evaporation. Final product with diameter of 150 μm, surface roughness of 30 nm, and sphericity of 98.0% was obtained. The possible influences on the formation of PS hollow sphere were also discussed.     

空心微球/环氧树脂复合泡沫塑料的抗压性能与破坏机制

以环氧树脂为基体, 不同粒径空心玻璃微球为填充体, 制备了轻质高强复合泡沫塑料。通过单轴准静态压缩试验研究了空心微球的粒径大小对复合泡沫塑料的抗压性能的影响, 并采用SEM对复合泡沫塑料的微观结构进行观测。通过随机空间分布法建立了空心玻璃微球/环氧树脂复合泡沫塑料的实体模型, 并且使用有限元分析软件对复合泡沫塑料在1 kPa载荷下的应力分布进行了分析。结果表明, 在相同体积含量下, 当空心微球的粒径从30 μm增大到120 μm时, 复合泡沫塑料的抗压强度无明显变化。有限元分析的结果表明, 在复合泡沫塑料中主要承载部分为空心微球, 空心微球上的应力大于树脂基体上的应力。最大应力分布在空心微球的内壁, 结合SEM图像可推测, 空心微球在破裂之前受到充分的挤压, 并且从内壁产生裂纹。     

Bubbles in solvent microextraction: the influence of intentionally introduced bubbles on extraction efficiency

Significant improvements to microdrop extractions of triazine pesticides are realized by the intentional incorporation of an air bubble into the solvent microdroplet used in this microextraction technique. The increase is attributed partly to greater droplet surface area resulting from the air bubble being incorporated into the solvent droplet as opposed to it sitting thereon and partly to thin film phenomena. The method is useful at nanogram/liter levels (LOD 0.002-0.012 μg/L, LOQ 0.007-0.039 μg/L), is precise (7-12% at 10 μg/L concentration level), and is validated against certified reference materials containing 0.5 and 5.0 μg/L analyte. It tolerates water and fruit juice as matrixes without serious matrix effects. This new development brings a simple, inexpensive, and efficient preconcentration technique to bear which rivals solid phase microextraction methods.     

中国夏季硫酸盐气溶胶间接辐射强迫的数值模拟

运用发展的区域系统集成模式RIEMS,结合Slingo参数化方案,研究了中国夏季硫酸盐气溶胶对云特性(云滴有效半径)的影响及其所产生的间接辐射效应。模拟的云滴尺度分布基本合理,数值在0～10μm之间,但与卫星数据MODIS相比偏小。硫酸盐气溶胶间接辐射强迫7月平均值为-2.58W/m2,空间变化在-10～-1W/m2之间,最大值出现在东北长白山地区,陆地上的负强迫大于海洋。间接辐射强迫与气溶胶浓度分布和云水分布有密切的关系。