聚甘油脂肪酸酯W/O/W多重乳液的稳定性研究

以聚甘油-2-二油酸酯、十聚甘油单月桂酸酯分别替代Span-80、Tween-80作为W/O、O/W乳化剂，以液体石蜡作为油相制备W/O/W多重乳液；以乳液的分层率作为乳液稳定程度的标准，探讨了乳化剂种类、乳化剂质量分数及油水体积比对W/O/W多重乳状液体系稳定性的影响。借用旋转流变仪对乳液流变性能进行测定，探讨脂肪醇（C_(m )H_(2m+1)OH,m=12,14,16,18和20）、高聚物（黄原胶、羟乙基纤维素、小核菌胶）对W/O/W多重乳液流变性质的影响。结果表明稳定的W/O/W多重乳液较优组成，初级乳液（W/O）：聚甘油-2-二油酸酯质量分数为10%,V（液体石蜡）∶V（水）=?2∶1;W/O/W多重乳液：十聚甘油单月桂酸酯质量分数为6%,V（初级乳液）∶V（水）=9∶10，脂肪醇（十六醇）质量分数为2%，高聚物（黄原胶）质量分数为0.15%。     

含聚合型乳化剂反相乳液体系的稳定性研究

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。     

AM/AMPS/SSS三元反相乳液聚合体系稳定性研究

以丙烯酰胺(AM)为主单体、2-甲基-2-丙烯酰胺基丙磺酸(AMPS)、对苯乙烯磺酸钠(SSS)为抗温抗盐单体,以白油为连续相,Span 80/Tween 80为复合乳化剂,制得了AM/AMPS/SSS三元反相乳液聚合体系,考察了HLB值、乳化剂浓度、油水比、pH值、搅拌时间、搅拌速度对乳液稳定性的影响。结果表明,乳化剂含量为6%～7%(体系总量),HLB值为5.89,体系pH=8,油水体积比为1.8∶1,搅拌时间30～40 min,搅拌速度为500 r/min时得到稳定的反相乳液体系,适合进行三元反相乳液聚合。     

撞击流-旋转填料床制备丙烯酰胺反相乳液及其稳定性研究

以撞击流-旋转填料床为乳化设备,煤油为有机介质,山梨醇酐油酸酯(Span 80)和烷基酚聚氧乙烯醚(OP-10)为复配乳化剂制备了丙烯酰胺反相乳液,研究了超重力因子、撞击速度、油水体积比、乳化剂质量分数、复配乳化剂HLB值以及丙烯酰胺单体质量分数对乳液稳定性的影响,并与搅拌式乳化装置进行了对比研究。结果表明:在超重力因子为65.32,撞击速度为12.58 m/s,V(油相)∶V(水相)=1∶1,乳化剂质量占乳液总质量的5%,复配乳化剂HLB值为6.0,丙烯酰胺单体质量占单体水溶液总质量的15%的条件下,所制备乳液平均粒径为664 nm,稳定性系数达0.973;对比研究发现,采用撞击流-旋转填料床制备的乳液稳定性好,粒径小,分散均匀,乳化时间短,为连续化制乳过程。     

环保型船用艉轴油乳化稳定性的研究

为了考察乳化剂和助乳化剂对环保型船用艉轴油乳化稳定性的影响,分别以乳状液的储存时间、离心析水量和乳液的平均粒径及其粒径分布作为乳状液稳定性的评价指标,研究了乳化剂种类、HLB值、乳化剂质量分数、助乳化剂种类以及助乳化剂质量分数对环保型艉轴油乳化稳定性的影响。结果表明:在环保型船用艉轴油体系中,乳化剂Span 80和Tween 80复配效果最好,且最佳HLB值为6。添加助乳化剂Hypermer B246能进一步增强乳状液的稳定性。提高乳化剂和助乳化剂的质量分数均可增加乳状液的储存时间,降低乳状液的离心析水量和平均粒径,从而提高乳状液的稳定性。     

人工胶乳法制备氯化橡胶的研究

研究了一种制备氯化橡胶的人工胶乳新方法。采用氯苯作为溶剂,溶解天然橡胶后,加入一定量乳化剂和水,制备人工胶乳体系,然后通氯气进行反应,并通过乙醇醇析得到产品。考察了HLB值,乳化剂种类、用量和油水比对乳液体系稳定性的影响,考察了不同体系的氯化反应过程和乙醇脱溶剂过程。实验结果表明,合适的反应条件为:HLB=14,w(Span80+Tween80)=0.4%,油水比为1∶7.5或w(Span80+LAS)=0.3%,油水比为1∶3,在常压,60°C下,反应时间10~12 h。     

O/W型抗紫外纳米乳液的制备及其性能研究

选用非离子型表面活性剂Span-80和Tween-40为乳化剂,以环己烷为油相,采用反相乳化法,制备具有抗紫外效果的高分散纳米乳液。通过测定乳液的平均粒径和稳定性能,研究了乳化剂的组成,分散相体积分数,乳化剂用量和乳化温度等因素对乳液体系稳定性的影响,探索该乳液制备的最佳条件。结果表明,以Span80和Tween40按质量比1∶1作为乳化剂,乳化剂用量为4%,分散相体积分数10%,乳化温度为55℃,10 000 r/min下乳化10 min,可获得平均粒径在150 nm以下的乳液,且具有较好的稳定性及抗紫外线性能。     

O/W型抗紫外纳米乳液的制备及其性能研究

选用非离子型表面活性剂Span-80和Tween-40为乳化剂,以环己烷为油相,采用反相乳化法,制备具有抗紫外效果的高分散纳米乳液。通过测定乳液的平均粒径和稳定性能,研究了乳化剂的组成,分散相体积分数,乳化剂用量和乳化温度等因素对乳液体系稳定性的影响,探索该乳液制备的最佳条件。结果表明,以Span80和Tween40按质量比1∶1作为乳化剂,乳化剂用量为4%,分散相体积分数10%,乳化温度为55℃,10 000 r/min下乳化10 min,可获得平均粒径在150 nm以下的乳液,且具有较好的稳定性及抗紫外线性能。     

超声制备甲醇柴油乳液及其稳定性研究

采用Tween 80,Span 80,Tween 20,油酸和十二烷基磺酸钠复配作为乳化剂,利用高速分散器和超声波装置作为预乳化和深度乳化装置制备甲醇柴油乳液。研究了超声参数(声强和作用时间)、乳化剂及甲醇用量等对甲醇柴油乳液稳定性的影响,得出适宜的操作条件为:复配乳化剂HLB值为5.1,复配乳化剂质量分数为3%,甲醇体积分数为15%,预乳化时间为5 min,转速为5×2 800 r/min,超声乳化时间为15 min,超声作用功率为352 W。     

油包水包油型多重结构乳状液稳定性的影响因素研究

运用两步乳化法制备油包水包油(O/W/O)型多重结构乳状液,研究了乳化剂种类、乳化剂用量、相体积比和添加剂等因素对O/W/O多重结构乳状液的形成和稳定的影响。实验结果表明,O/W脂肪醇聚氧乙烯醚-21EO (S21)、聚氧乙烯-聚氧丙烯嵌段共聚物(F127)以及W/O环甲基硅氧烷(及)PEG/PPG-18/18聚二甲基硅氧烷(DC5225)的最佳质量分数均为5%;当内油相的Si-451质量分数为15%、水相的Si451质量分数为30%时是形成多重结构乳液的最佳质量分数;质量分数为2%的单甘酯(GMS)对多重结构的形成和稳定起着重要的作用;1,3-丁二醇的加入有效地提高了多重结构稳定性。     

石蜡油w／o／w型多重乳液的制备及其对维生素C的包裹

以多重乳液相对体积为衡量标准,探讨了石蜡油、乳化剂、以及第一相质量分数对石蜡油w／o／w型多重乳液稳定性的影响。结果表明制备石蜡油w／o／w型多重乳液的较佳条件为：第一相中石蜡油和乳化剂Span80质量分数分别为40％和8％,第一相质量分数为65％,乳化剂Tween80质量分数为1％。采用透析-紫外分光光度法研究了该多重乳液对维生素c的包裹能力,结果表明：多重乳液可以有效包裹维生素C,包裹率达98．55％,且能缓慢释放被包裹的维生素C。     

玉米油W1/O/W2型多重乳状液稳定性的研究

高脂食品严重危害着人类健康,这引起人们对低脂食品的的不断追求,因此脂肪替代品的开发越来越受到人们重视。本试验以玉米油和生物高聚物为主要原料通过两步乳化法制备W1/O/W2多重乳状液作为脂肪替代品(FS),以离心稳定性为衡量标准,用显微镜直接观察,探讨了初复乳乳化工艺、各相相对体积比对玉米油W1/O/W2型多重乳状液体系稳定性的影响。结果表明:1.影响玉米油多重乳状液稳定性的主要因素有:复乳的乳化工艺,内水相与油相体积之比等。2.两步乳化工艺中第二步乳化工艺对复乳稳定性影响较大,其规律是随着乳化强度的提高,粒径减小,稳定性呈上升趋势,适宜的乳化条件为7200 r.min.1,13 min,而第一步乳化工艺对复乳稳定性几乎没有影响。3.内水相与油相、初乳与外水相均是影响复乳稳定性的主要因素,前者主要是依靠改变初乳黏度来影响复乳稳定性,后者主要是乳滴间范德华力与电排斥力共同作用的结果,适宜的体积比分别为1:4和1:1。     

The effect of shear and oil/water ratio on the required hydrophile-lipophile balance for emulsification

Required hydrophile-lipophile balance (HLB) values were examined in terms of the nature of kerosene-water, both oil-in-water (O/W) and water-in-oil (W/O), emulsions formed using Span 80/Tween 80 surfactant blends. Both the nature of the emulsification method and the oil/water ratio were critical in determining the resulting emulsion type. Both high- and low-shear conditions were investigated. Under high shear, low internal phase emulsions formed using the surfactant mixtures that corresponded to the required HLB values for emulsification involving kerosene (6 for W/O and 14 for O/W). However, at low shear, high internal phase (concentrated) emulsions resulted. Furthermore, depending on the oil/water ratio, some of the high internal phase emulsions were opposite to the type expected, given the HLB of the surfactant blend used. From these results, it appears that the emulsification technique (applied shear and oil/water ratio) used can be of greater importance in determining the final emulsion type than the HLB values of the surfactants themselves.     

Efficient Encapsulation of a Water-Soluble Molecule into Lipid Vesicles Using W/O/W Multiple Emulsions via Solvent Evaporation

We developed a novel method for preparing lipid vesicles with high entrapment efficiency and controlled size using water‐in‐oil‐in‐water (W/O/W) multiple emulsions as vesicle templates. Preparation consists of three steps. First, a water‐in‐oil (W/O) emulsion containing to‐be‐entrapped hydrophilic molecules in the water phase and vesicle‐forming lipids in the oil phase was formulated by sonication. Second, this W/O emulsion was introduced into a microchannel emulsification device to prepare a W/O/W multiple emulsion. In this step, sodium caseinate was used as the external emulsifier. Finally, organic solvent in the oil phase was removed by simple evaporation under ambient conditions to afford lipid vesicles. The diameter of the prepared vesicles reflected the water droplet size of the primary W/O emulsions, indicating that vesicle size could be controlled by the primary W/O emulsification process. Furthermore, high entrapment yields for hydrophilic molecules (exceeding 80 % for calcein) were obtained. The resulting vesicles had a multilamellar vesicular structure, as confirmed by transmission electron microscopy.     

Novel evaluation method for the water- in- oil (W/O) emulsion stability by Turbidity Ratio Measurements

The turbidity ratio method of evaluating the stabilities of water-in-oil emulsions has been established with two wavelengths (450 and 850 nm) by taking the intensity ratio of two beams. The slopes of turbidity ratio of several water-in-oil emulsions with time were calculated to evaluate the emulsion stabilities at different HLB (Hydrophilie-Lipophile Balance), the amounts of emulsifiers, and water contents. The results of the turbidity ratio technique were consistent with the amount of phase separation of emulsions incubated for 30 days at room temperature. From the turbidity ratio measurements, we determined that the required HLB of diesel oil was about 6.0, and that the stability of emulsion increased with the amount of emulsifier. The increasing amount of the water showed a negative effect on emulsion stability. Finally, this method provides a useful tool for the quick evaluation of the required HLB and the condition of emulsification throughout this study.     

Mechanical Entrainment in W/O/W Emulsion Liquid Membrane

Abstract

An experimental study of mechanical entrainment in W/O/W emulsions is conducted. W/O/W emulsions are stirred for various stirring times under the conditions that mechanical entrainment solely occurs, and changes in volume of the W/O emulsions and size distribution of the internal water droplets are measured. The rate of change in number of the water droplets entrained is found to be proportional to the volume fraction of W/O emulsions. Based on this result, a new model for mechanical entrainment is developed. The calculated change in W/O emulsion volume with time agrees with the observed ones except in the region near phase inversion. Then, phase inversion is discussed.     

用聚合型乳化剂制备反相乳液的研究

以丙烯酸钠水溶液为水相,煤油为油相,Span80甲基丙烯酸酯(Span80 MA)聚合型乳化剂、Span80和Twen80为复配乳化剂,制备反相乳液。计算聚合型乳化剂(Span80MA)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规律。结果显示:HLB(Span80MA)=4.0;形成稳定的反相乳液理想条件为:Span80MA∶Span80∶Twen80=0.7∶0.5∶0.2;乳化剂浓度为7%;φ=50%;单体浓度为2.0～3.0 mol/L。     

A novel method for preparing oil-in-water-in-oil type multiple emulsions using organophilic montmorillonite clay mineral

A stable formula using oil-in-water-in-oil (O/W/O) type multiple emulsions was investigated. The components consisted of hydrophilic nonionic surfactant (HCO-60), organophilic montmorillonite, and lipophilic nonionic surfactant (DIS-14). O/W/O emulsions were prepared by a double-step procedure in which an O/W emulsion was prepared in the first step, and then the O/W emulsion was “re-emulsified” in an oil phase with organophilic montmorillonite. The diameter of the innermost oil droplets decreased with increasing HCO-60 content (0.1–3%), while the viscosity showed a maximum at 1% of HCO-60, indicating that the yiel of re-emulsification is highest at this condition. Viscosity of the O/W/O emulsion increased with increasing organophilic montmorillonite and DIS-14. According to the results of a phase ratio study, viscosity and stability of the O/W/O emulsion decreased at high weight fraction of inner oil phase (0.4–0.5), indicating that the excess amount of inner oil phase is absorbed by the outer oil phase. These results revealed that the weight fraction of inner oil phase should be kept below 0.3 for a stable O/W/O emulsion. A similar study on the weight fraction of O/W phase [фO/W)/O] suggested that the O/W/O emulsion is stable at ϕ(O/W)/O=0.65–0.70.