甲酸盐在纳米AgBr／I粒子乳剂中的增感作用

分别以鱼明胶和骨明胶(惰胶)作为分散介质制备了两种不同形貌与粒径的纳米AgBr／I粒子乳剂．利用掺入作为正空穴捕获剂的甲酸盐，可以使本征感光度很低的纳米粒子乳剂的感光度有相当大的提高，显示甲酸盐具有很好的增感效果．对鱼明胶介质中制备的纳米AgBr／I粒子乳剂，甲酸盐掺杂方式不同其增感效果不一样．在乳剂颗粒中均匀掺杂增感效果最好，而趋向于近表面掺杂则增感效果降低，显示出甲酸盐掺杂的位置效应．籽晶掺杂后包壳的复合结构乳剂颗粒与均匀掺杂乳剂颗粒的增感效果近似．对鱼明胶介质中制备的掺杂甲酸盐的纳米AgBr／I粒子乳剂再进行硫增感或硫加金增感，乳剂感光度可进一步提高，表明甲酸盐掺杂与常规的硫增感或硫加金增感有很好的协同作用．     

溴化银乳剂中甲酸盐掺杂的位置效应研究

使用反馈式微机控制双注仪，在晶体生长过程的不同时刻，加入一定浓度的甲酸盐，制得了一系列甲酸根离子处于不同掺杂位置的立方溴化银微晶乳剂．对其感光性能的测试结果表明，(1)甲酸盐掺杂乳剂与未掺杂乳剂相比，感光度有显著提高；(2)甲酸根的掺杂位置越接近晶体表面，其感光度增益越大；(3)甲酸盐掺杂乳剂可同时与常规的硫加金化学增感和光谱增感进行协同增感；(4)光谱增感后的掺杂乳剂在延伸的光敏区内仍表现出明显的掺杂增感效应，但其增感倍率要低于乳剂在本征光敏区(蓝区)的增感倍率；(5)所有的掺杂乳剂，包括原始、硫加金和光谱增感的掺杂乳剂，它们的灰雾均保持在相当低的水平．     

溴化银乳剂中Ag2掺杂的位置效应研究

使用微机控制的双注仪，在晶体生长过程的不同时刻，加入一定浓度的二甲基胺硼烷（DMAB），制得了一系列Ag2处于不同掺杂位置的立方体溴化银微晶乳剂．对这些乳剂感光性能的研究表明：1）他掺杂乳剂与未掺杂乳剂相比，感光度有显著提高；2）心掺杂乳剂可同时与常规的硫加金化学增感和光谱增感进行协同增感；3）心掺杂接近微晶表面时乳剂感光度的增幅最大；4）在本实验条件下，掺杂乳剂的灰雾均保持在较低的水平。     

甲酸和草酸盐掺杂的AgBr乳剂对亲水型PTG材料感光性能的影响

研究了甲酸盐掺杂和草酸盐掺杂对AgBr乳剂和亲水型PTG材料感光性能的影响．实验结果表明，掺杂后的AgBr乳剂在PTG材料中作为光敏元显著提高了其相对感光度，而不引起灰雾的增加；掺杂增感与硫增感、金增感、硫加金增感在PTG材料中同样表现出协同增感效果，使PTG材料的感光度得到进一步的提高；掺杂后的AgBr乳剂在PTG材料中具有一个最佳使用量，即AgBr与硬脂酸银的摩尔比为1：4．     

甲酸盐掺杂立方八面体溴化银乳剂颗粒的增感效应研究

使用反馈式微机控制双注乳化仪，制备了甲酸根离子掺杂于颗粒次表面的立方八面体溴化银微晶乳剂，经计算此类颗粒上的（100）面与（111）面之比约为2：3，感光性能测试结果表明，甲酸根掺杂乳剂，无论是原始乳剂，还是经过化学增感，或染料光谱增感后的乳剂，其感光度都要明显高于相应的参考未掺杂乳剂（Sd／S0≈2），而灰雾水平则无明显增长。     

草酸盐掺杂八面体溴化银颗粒乳剂的增感效应研究

使用反馈式微机控制双注乳化仪,在晶体生长过程中一定时间内,加入一定量的草酸盐,制得了草酸根离子处于晶体颗粒次表面的八面体溴化银微晶乳剂。考察其实验过程和测试其感光性能,结果表明:(1)草酸根掺杂于次表面的八面体溴化银乳剂与未掺杂乳剂相比较,无论是原始乳剂,还是经过化学增感,或用染料进行光谱增感后的乳剂,感光度均有明显提高(Sd/S0≥1.8),且其灰雾水平都不高,即具有明显的增感效应;(2)草酸根掺杂的乳剂可以与常规的硫加金化学增感,以及染料光谱增感一同进行协同增感,把乳剂的感光度提高到更高的水平。(3)草酸根掺杂的八面体溴化银乳剂的感光度增益,明显高于草酸根掺杂立方体溴化银乳剂。     

草酸根掺杂立方体溴化银乳剂颗粒的增感效应研究

使用反馈式微机控制双注乳化仪，在晶体生长过程中一定时间内，加入一定量的草酸盐，制得了草酸根离子处于晶体颗粒次表面的立方体溴化银微晶乳剂．对其实验过程的考察和感光性能的测试结果表明，（1）草酸根掺杂于次表面的溴化银乳剂与未掺杂乳剂相比较，无论是原始乳剂，还是经过化学增感，或用染料进行光谱增感后的乳剂，感光度都有明显提高（Sd／S0≥1．5），有明显的增感效应；（2）无论是原始乳剂，还是经过化学增感，或光谱增感后的乳剂，草酸根掺杂立方体溴化银乳剂颗粒的灰雾水平都不高；（3）草酸根掺杂立方体溴化银颗粒与甲酸根掺杂的溴化银乳剂相比，产生的增感效应相差不大；（4）与甲酸根掺杂立方体溴化银颗粒相比，草酸根掺杂立方体溴化银颗粒的制备方法明显较前者要简单得多，颗粒形状也优于前者．     

甲酸根掺杂立方体溴碘化银微晶乳剂的增感效应研究

使用反馈式微机控制双注仪,在晶体生长不同时期,依次加入不同量碘盐和一定量甲酸盐,制得了两个系列的溴碘化银乳剂:一系列为碘含量分别为乳剂颗粒总银量的0、2×10-2、3×10-2、4×10-2和5×10-2I-mol/Ag mol的溴碘化银颗粒乳剂;另一系列为碘含量与上述系列乳剂相同,并掺杂有1×10-4mol/Ag mol甲酸根的溴碘化银颗粒乳剂.对其感光性能的测试结果表明,经过化学敏化和光谱增感后,甲酸根掺杂的溴碘化银乳剂较未掺杂甲酸根的乳剂,感光度显著提高,在一定量的I-掺杂范围内(0—4×10-2I-mol/Ag mol),灰雾没有明显增加.     

AgBrⅠ核壳乳剂的还原敏化与硫加金敏化的协同增感效应

使用微机控制的双注仪和二次乳化方法制备了一系列在AgBrⅠ核内进行不同程度还原增感的溴碘化银／溴化银核壳乳剂．对这些乳剂感光性能的研究表明：1)颗粒内部经还原敏化或Ag2掺杂的乳剂表现出明显的增感效应，颗粒内碘离子的存在并不影响Ag2的增感作用；2)在对乳剂进行了颗粒表面的硫加金增感以后，在一定的DMAB用量下，观察到显著的颗粒内部还原增感和表面硫加金增感的协同增感效应，使乳剂的感光度有了成倍的增长．以上协同增感效应的结果再次说明，颗粒内部的还原敏化中心与颗粒表面的硫加金敏化中心具有两种不同的增感机理，前者捕获空穴，后者捕获电子，两者都有利于提高潜影的形成效率。     

草酸根掺杂板状溴碘化银颗粒乳剂的增感效应研究

使用反馈式微机控制双注乳化仪,在晶体生长过程中一定时间内,加入一定量的草酸盐,制得了草酸根离子处于晶体颗粒次表面的板状溴碘化银微晶乳剂.对其实验过程的考察和感光性能的测试结果表明:1)草酸根掺杂于次表面的溴碘化银乳剂与未掺杂乳剂相比较,经过化学增感后,或光谱增感后的乳剂,其感光度有明显提高(Sd/S0≥1.5),即具有明显的增感效应;2)无论是经过化学增感,还是经光谱增感后的乳剂,草酸根掺杂溴碘化银颗粒乳剂的灰雾水平都不高.     

智能响应型Pickering乳液的制备及在物质分离中的应用进展

Pickering乳液是指由微纳米固体粒子代替传统表面活性剂作为乳化剂而稳定的乳液,具有较强的稳定性和超高油/水界面,能够为多相界面反应和物质传输提供高效稳定的场所。Pickering乳液的乳滴结构和性质与固体颗粒的尺寸形貌及表面性质密不可分,通过调控固体颗粒本身或表面的性质可以赋予Pickering乳液特定的响应性功能,拓宽其应用领域。本文对近年来不同响应型（磁性、CO₂、pH、光、温度等响应型）的Pickering乳液的主要研究成果进行了综述,重点介绍了Pickering乳液的稳定性原理、响应型Pickering乳液的制备方法和结构调控策略,以及近年来Pickering乳液在物质分离提取中的应用研究进展,最后对智能响应型Pickering乳液应用研究的发展趋势进行了展望。     

Effects of Nanoparticles on Film Properties of Waterborne Acrylic Emulsions

Waterborne acrylic emulsion was obtained by using methyl methacrylate, ethyl and butyl acrylate monomers. Emulsions containing nanoparticles were prepared by blending the stable dispersions containing SiO₂ or MMT nanoparticles. The films were prepared from emulsions and coating tests were applied. The physical properties of prepared emulsions are better than the commercial emulsions. The addition of the nanoparticles especially SiO₂ have positive effect on the resistance to environmental conditions of emulsions. Waterborne acrylic emulsions containing nanoparticles prepared in this study can be used in the manufacturing of the semi-lustrous emulsion type nano paint with low cost, high performance and environmentally friendly.     

Comparison of fuel properties and emission characteristics of two- and three-phase emulsions prepared by ultrasonically vibrating and mechanically homogenizing emulsification methods

Emulsions have long been considered as an alternative fuel for combustion equipment in order to achieve better fuel economy and pollution reduction. While a mechanical homogenizing method is frequently used to prepare emulsions, the use of an ultrasonic emulsification method to do so is still rather limited, and is mostly applied to two-phase emulsions only. Hence, two-phase W/O and three-phase O/W/O emulsions, prepared by a mechanical homogenizer and an ultrasonic vibrator, respectively, were prepared and used as engine fuel. The emulsion properties, engine performance, and engine emission characteristics between these two emulsification methods were measured and compared. The potential of the ultrasonic emulsification method was also evaluated. The experimental results show that the emulsions prepared by the ultrasonic vibrator appeared to have more favorable emulsification characteristics such as smaller dispersed water droplets that were distributed more uniformly in the continuous oil phase, lower separation rate of water droplets from the continuous phase of diesel fuel and thus a lower separating rate of the dispersed water droplets from the emulsion, larger emulsion stability, and larger emulsion viscosity than the emulsions produced using a mechanical homogenizer. In addition, a larger content of water was emulsified when the emulsion was prepared using the ultrasonic vibrator than the mechanical homogenizer. The emulsions prepared by the ultrasonic vibrator also had a lower fuel consumption rate, lower bsfc, and significantly lower CO emission while at the same time having a larger black smoke opacity. When comparing the two-phase W/O and the three-phase O/W/O emulsions prepared by either the ultrasonic vibrator or the mechanical homogenizer, the two-phase W/O emulsions appeared to have a lower fuel consumption rate, bsfc, CO, and a lower black smoke opacity than the three-phase O/W/O emulsions, regardless of whether they were prepared by ultrasonic vibrator or mechanical homogenizer.     

Spray-Dried Redispersible Emulsion to Improve Oral Bioavailability of Itraconazole

Dry emulsions are powdery, lipid-based formulations from which an o/w-emulsion can be easily reconstituted in vivo or when exposed to water. The objective of this work was to prepare and characterize dry emulsion of itraconazole (ITZ) to improve its solubility and bioavailability. Dry emulsions were prepared by spray-drying liquid o/w-emulsions containing carriers like maltodextrin, sucrose, and lactose. Propylene glycol monocaprylate was selected as oil phase, and surfactant blends of vitamin E tocopherol polyethylene glycol succinate and triblock PEO–PPO–PEO copolymer as emulsifying agents. Several oil:water and carrier:water ratios were tested. An optimum formulation was selected using 3² full factorial design. The droplet size, rheological behavior, and drug release from o/w-emulsion before and after reconstitution and the micromeritic properties of spray-dried product were investigated. Maltodextrin was used as a carrier for preparing dry emulsions. The optimized dry emulsion was characterized using DSC, SEM, PXRD, and in vivo study. The SEM analysis showed that dry emulsion consisted of well-separated particles with smooth surfaces. The DSC and XRD study showed that ITZ in the dry emulsion is in the molecular dispersion state. Globule size analysis showed that dry emulsion had good reconstitution properties. The emulsions were found to be thermodynamically stable when subjected to cyclical freeze–thaw cycles and centrifugation tests. The average globule size of emulsions ranged from 0.994 to 1.668 μm. A 71.35 % increase in C _max and 114.78 % increase in AUC was evident for ITZ dry emulsion as compared to plain ITZ.     

Rheology and stability of phospholipid-stabilized emulsions

Lecithin in cosmetic emulsions produces a unique “skin feel,” which can be related to its rheological properties. In this study, water-in-oil (w/o) and oil-in-water (o/w) emulsions were made from a cosmetic-grade caprylic/capric triglyceride with deoiled lecithin and hydroxylated lecithin. Synthetic surfactants commonly used in commercial cosmetic products were used as controls. Optical light microscope investigation showed significant differences in the structures of the w/o and o/w emulsions made with the lecithins. Freeze/thaw tests were conducted to evaluate emulsion stability. The o/w emulsion (oil/water = 20:80) was stable with 3% hydroxylated lecithin at room temperature. However, 4% hydroxylated lecithin was needed for stabilizing the emulsion with an oil-to-water ratio of 20:80 or 30:70 through the freeze/thaw treatments. With 4% deoiled lecithin, the w/o emulsion showed a water-holding capacity up to 80%, which was also stable through two freeze/thaw cycles. All emulsions in this study exhibited pseudoplastic flow, in which a minimum shearing stress, a yield value, was required before flow became linear. In general, the emulsion viscosity increased as lecithin content increased. Changing the oil-to-water ratio also affected the emulsion viscosity. The deoiled lecithin-based w/o emulsions had higher yield values than hydroxylated lecithin-based o/w emulsions. Therefore, more force was needed to spread the w/o emulsions. In addition, because w/o emulsions had more viscous continuous phases and a greater volume of internal phases, the w/o emulsions were more viscous than the o/w emulsions.     

交联聚合物微粒改性乳液聚合物工艺研究

采用乳液聚合法合成了成膜性很好的聚合物乳液和交联聚合物微粒 (CMP)乳液 ,并将二者共混 ,研究了CMP对聚合物乳液的成膜性及膜性能的影响 ,试验表明CMP对合成的乳液聚合物涂膜有增强作用 ,但其改性工艺仍需改进。对CMP的合成稳定性、成膜性和膜强度以及功能单体对CMP的改性性能也进行了讨论     

聚丙烯酸酯／纳米SiO_2复合压敏胶乳液的性能及影响因素

采用原位乳液聚合法成功制备了高性能的聚丙烯酸酯／纳米SiO2有机-无机复合压敏胶乳液。TEM 及粘接性能测试的结果表明:纳米SiO2能有效地被分散到纳米量级并以此量级与原位生成的聚丙烯酸酯复合,纳米SiO2的引入能同时提高乳液的内聚力和剥离强度。考察了纳米SiO2含量、硬单体和功能单体的用量及乳化剂的加入方式等对复合乳液压敏性能的影响。所得复合乳液放置3个月后仍有理想的压敏性能,存贮稳定性良好。     

Emulsification characteristics of three- and two-phase emulsions prepared by the ultrasonic emulsification method

Diesel engines exhausting gaseous emission and particulate matter have long been regarded as one of the major air pollution sources, particularly in metropolitan areas, and have been a source of serious public concern for a long time. The emulsification method is one of the potentially effective techniques to reduce emission pollution from diesel engines. Ultrasonic waves are a kind of sound waves with a frequency larger than 20 kHz, and they cannot be detected by the human ear. The phenomena of cavitation and hot spots produced by the rather violent action of ultrasonic waves can cause rapid chemical and physical reactions. This allows immiscible liquids to be well stirred with each other by means of ultrasonics. An ultrasonically vibrating machine that provides ultrasonic waves of a 40-kHz frequency was employed to prepare two- and three- phase emulsions in this experimental study. The fuel properties and the emulsion stability of the diesel emulsions were measured and analyzed. Experimental results show that the ultrasonic emulsification method successfully prepared two- and three-phase emulsions with tiny dispersed-phase droplets that are very evenly distributed in the outer oil or water phase. The ultrasonic processing time, quantity and HLB of the emulsifying agent were noted to have determinative influences on the formation of the emulsion and the fuel properties. A longer ultrasonic processing time caused less un-emulsified diesel fuel, smaller sizes and a more even distribution of dispersed-phase droplets in the outer oil phase and larger emulsion viscosity. However, a longer ultrasonic processing time also produced a larger temperature rise in the emulsion, leading to the deterioration of the emulsion stability. The O/W emulsion was found to have the lowest percentage of separation and thus the highest emulsion stability among the O/W/O, O/W and W/O emulsions. In addition, in comparison with the W/O emulsion, the O/W emulsion was shown to have a smaller size and a more even distribution of the dispersed-phase droplets. It also had a lesser rise in emulsion temperature when the ultrasonic processing time increased. The control of the ultrasonic processing time is important to successfully prepare the three-phase O/W/O emulsion. Too long a vibration time at the second-stage of emulsification is shown to cause the dispersed-phase pellets to contract and congregate with the inner-phase droplets. The three-phase emulsion structure then finally disappears and transforms into a two-phase emulsion. The addition of 2% by volume of the emulsifier mixture of Span80 and Tween80 with a HLB = 8, as suggested by this study for the preparation of stable two- and three-phase emulsions, were observed to have the lowest percentage of separation of the W/O and O/W/O emulsions. For preparing a stable O/W emulsion, the proportion of the emulsifier could be as low as 1.5% by volume. The percentage of separation of the O/W/O emulsion was lower and less influenced by the change in emulsion temperature than was the W/O emulsion with the same water content. However, the O/W/O emulsion was found to have a larger viscosity and a more significant variation of its viscosity, depending on the ultrasonic processing time, than the W/O emulsion.