Influence of Two Salicylate Components on the Particle Size of an Oil-in-Water Emulsion with Nonionic Surfactants

Abstract

This paper reports a study undertaken using techniques of static and dynamic light scattering to investigate the influence of sodium salicylate and methyl salicylate on droplet size of oil-in-water emulsions. The rates of changes were measured by determining the size and distribution of the oil droplet in the material. All emulsions showed a bimodal size distribution; the mean diameters and polydispersity were calculated from intensity. These data were analyzed with nonlinear regressions and bootstrap methodology. An amount of methyl salicylate component induced a decrease of mean diameter and standard deviation. On the contrary, sodium salicylate entailed the growth of all droplet populations and coalescence for the highest concentration.     

CCD技术在光散射法测量微粒直径分布中的应用

本文提出了以线阵CCD光电探测阵列作为接收器,并以悬浮法测量固体粉末或混浊液中悬浮粒子大小及分布的激光粒度仪的设计方案;设计了径向散射光强分布的多周期间隔采样的CCD数据采集系统。使用研制的样机完成了多项实验,取得满意的结果。     

沉降颗粒激光反射像点粒度测量中的图像数字处理方法初探

本文介绍了一种通过对沉降颗粒激光反射像点运动图像的数字处理，获得颗粒沉降位移而得出Stokes粒径的粒度测量方法。该粒度测量方法是利用颗粒图像匹配算法，提取颗粒的特征图像区域，并以此颗粒图像为匹配模板的的颗粒跟踪技术。同时对该方法所采用的相关分析技术做了说明.     

表面活性剂浓度对乳胶基质平均粒径的影响和机理分析

乳胶基质内相液滴的平均粒径大小直接反映了可燃剂和氧化剂的混合均匀程度,是影响乳化炸药爆炸性能和稳定性能的重要因素。主要研究了油相中表面活性剂浓度对乳胶基质内相液滴平均粒径的影响。使用5种含有不同表面活性剂浓度的外相材料制备乳胶基质,并且使用激光粒度仪测试了所有样品的平均粒径。实验结果表明:油相材料中表面活性剂的浓度越大,则制备出的乳胶基质平均粒径越小。然后通过表面张力的理论分析和外相动力粘度的实验测试,进而分析出增加表面活性剂降低乳胶基质的平均粒径的机理:表面活性剂的增加导致了外相材料的动力粘度的增大,进而使乳胶基质平均粒径变小,和表面张力无关。     

X射线小角散射测定粒度分布的一种数据处理解析程序

本文提出了一种确定材料中微不均匀区大小分布 X 射线小角散射数据处理的解析方法。用 n 个分立的粒度分布解对应的散射强度叠加来逼近实验强度。以尝试法修正结果使误差达到最小。用铁红釉试样作为实例,对液相分离球滴粒度分布作了测定,结果表明该方法简便实用。     

Influence of Particle Size on the Distributions of Liposomes to Atherosclerotic Lesions in Mice

ABSTRACT

In order to confirm the efficacy of liposomes as a drug carrier for atherosclerotic therapy, the influence of particle size on the distribution of liposomes to atherosclerotic lesions in mice was investigated. In brief, liposomes of three different particle sizes (500, 200, and 70 nm) were prepared, and the uptake of liposomes by the macrophages and foam cells in vitro and the biodistributions of liposomes administered intravenously to atherogenic mice in vivo were examined. The uptake by the macrophages and foam cells increased with the increase in particle size. Although the elimination rate from the blood circulation and the hepatic and splenic distribution increased with the increase in particle size in atherogenic mice, the aortic distribution was independent of the particle size. The aortic distribution of 200 nm liposomes was the highest in comparison with the other sizes. Surprisingly, the aortic distribution of liposomes in vivo did not correspond with the uptake by macrophages and foam cells in vitro. These results suggest that there is an optimal size for the distribution of liposomes to atherosclerotic lesions.     

The Influence of Drug Solubility and Particle Size on the Pellet Formulation in a Rotoprocessor

ABSTRACT

Pellets containing drugs of different properties were prepared in a Rotoprocessor in order to study changes in the formulation process and resulting pellet characteristics. Diltiazem hydrochloride, diclofenac sodium, and theophylline were chosen as model drugs. Pellet size distribution, sphericity, density, hardness, friability, and repose angle were determined using standard methods. The amount of water as a wetting agent necessary for successful pellet formulation was observed for each sample and changed depending on drug solubility, concentration, and particle size. The pelletization of freely soluble diltiazem hydrochloride required 24.8–23.1% of the wetting agent and its amount decreased as the drug concentration increased. The demand for water in the formulation of theophylline pellets was 31.0–34.4% and it increased with increasing drug concentration. The pellet samples containing both drugs were easy to prepare. However, the cohesion of micronized diclofenac sodium particles negatively influenced both the pellet size distribution and the formulation process itself. When the drug concentration exceeded 40%, it was not possible to produce pellets of an appropriate size and the process was not reproducible.     

累积量算法在PCS中的颗粒粒径反演

介绍了应用光子相关光谱法测量纳米颗粒粒径的基本理论,该理论利用了悬浮于介质中的散射体的布朗运动所引起的散射光强涨落现象.详细分析了利用累积量算法反演光子相关光谱法测量中的颗粒粒径.针对已经标定的PMMA颗粒,利用累积量算法进行反演,对反演结果进行分析.累积量算法比较简单,计算快速,计算结果重复性好,对单分散颗粒系以及窄分布的颗粒系能给出较准确的平均粒径以及与颗粒粒径分布有关的一些参数.     

X射线小角散射法对纳米氧化锆粒度分布的研究

采用小角X射线散射法，在普通的X射线衍射仪上实现纳米级氧化锆粒度分布的表征；并按照国标（GB／T13221-2004）的标准，使用SAXS程序计算出纳米氧化锆的粒度分布范围在1-36nm之间。与纳米氧化锆的TEM图像相比较，对比结果表明该方法测得的纳米氧化锆粒度可靠。     

Influence of the Size of Micronized Active Pharmaceutical Ingredient on the Aerodynamic Particle Size and Stability of a Metered Dose Inhaler

Pharmaceutical inhalers are often used to treat pulmonary diseases. Only active pharmaceutical ingredient (API) particles from these inhalers that are less than approximately 5 µm are likely to reach the lung and be efficacious. This study was designed to investigate the impact of micronized API particle size on the aerodynamic particle size distribution (PSD) profile and the particle size stability of a suspension metered dose inhaler (MDI) containing propellant HFA‐227 (1,1,1,2,3,3,3 heptafluoropropane) and a corticosteroid. The median API particle size ranged from 1.1 µm to 1.8 µm (97% to 70% of particles <?3 µm, respectively). This study showed that increasing the particle size of the API used to manufacture a suspension MDI product increased the aerodynamic PSD of the MDI product. Furthermore, upon storage of the MDI product under temperature cycling conditions, samples containing larger‐size API particles were less stable with respect to their aerodynamic PSD than those with smaller‐size API particles. It was found that size‐dependent particle growth and/or aggregation of the suspended API may be occurring as a result of temperature cycling. In conclusion, this study has shown that the particle size of the raw API impacts the properties and stability of the emitted aerosol spray. Based on the findings from this study, it is recommended that the API particle size be carefully controlled in order to meet specifications set for the finished MDI product.     

复合分散剂对超细碳酸钙粒度测定的影响

采用激光粒度法测定了碳酸钙微粉的粒度．研究了遮光比、分散剂种类、分散剂用量、碳酸钙微粉在水中的质量分数碳酸钙微粉粒度测定的影响,得出最佳测定条件为：添加的复合分散剂为六偏磷酸钠与正丁醇,比例为10：3,遮光比为8-12时,测得的碳酸钙粒度分布与电子显微镜测得的粒度相吻合。     

水泥粒度分布对水泥性能影响的研究进展

从两个方面总结了水泥粒度分布对水泥性能影响的研究进展,一方面总结了反映水泥颗粒群整体情况的特征参数比表面积S、特征粒径x′和均匀性指数n对水泥性能的影响;另一方面总结了不同粒径区间水泥颗粒的性能。介绍了描述水泥粒度分布的RRB方程和Fuller曲线,综述了理论上粒度分布对水泥性能的影响情况,认为水泥的粒度分布是与其性能有明确定量关系的细度参数,是水泥粉磨细度控制的最终目标。     

固相颗粒粒径对浆体流变特性影响的实验研究

为研究固相颗粒粒径大小对冰浆类固液两相流流变特性的影响,本文选用三种平均粒径分别为0.31、0.43和0.51 mm的聚乙烯颗粒(密度约为0.922 g/cm3)作为固相,改变混合浆体的流速及固相质量分数,测量浆体在水平圆管内流动的压降值,根据剪切应力与剪切速率的关系,确定了分段拟合流变方程的方法,分析了固相颗粒粒径大...     

Influence of Particle Size and Heating Rate on Decomposition of BC Dry Chemical Fire Extinguishing Powders

Pyrolysis of BC dry chemical fire extinguishing powders which are useful for Class “B” and Class “C” fires was conducted on a thermogravimetric analyzer with sample loading of 10–25 mg under dynamic air atmosphere. The effect of particle sizes (medium value 48.99, 27.24, 4.93 µm) and heating rates (10, 15, and 20°C min^?1) were examined. The pyrolysis kinetics of the samples was analyzed using a distribution activation energy model. It was found that the decomposition temperature decreased and the pyrolysis rate increased after the samples were milled. The agglomeration of particles during production did not have an appreciable influence on the pyrolysis process of the samples in our experimental conditions. The activation energy value was 77.13?219.78 kJ · mol^?1, 58.18?288.67 kJ · mol^?1, and 44.59?209.17 kJ · mol^?1 for the powder of particle size 48.99, 27.24, 4.93 µm. We should use micro powder in fire extinguishing.     

籽晶粒径分布对高效多晶硅晶体生长的影响

采用不同粒径分布的单晶籽晶进行高效多晶硅铸锭,结果表明单晶籽晶的粒径分布对引晶效果影响显著.籽晶粒径在1～4mm范围时,引晶效果最佳;粒径大于4mm时,硅熔体流延现象的存在导致长晶初期晶体中位错密度偏高,少子寿命降低;粒径小于1 mm时,细小的形核点也会影响晶体中的位错密度和少子寿命.对应电池片效率的结果也验证了该结论.     

粉体粒度分布分维与流动性及滑石对流动性影响

通过粉体粒度分布分形维表征粒度分布和粉体流动性,并研究滑石粉对不同分形维粉体的流动性的影响.结果表明,粉体粒度分布分形维能很好的表征粉体的流动性能;流动助剂滑石粉掺入质量分数小于2%时,粒度分布分形维越小的粉体,其流动性改善越显著;当掺入质量分数为3%～5%时,各不同粒度分布分形维值粉体流动性变化平缓.     

不同化学助剂对水性印刷油墨颗粒粒径的影响

目的 纸基包装材料多采用水性油墨印刷,在此类废纸回用过程中通过增加水性油墨颗粒的粒径,可以有效避免或减轻由于其粒径过小而造成的在纤维上的二次沉积与吸附,也可增加水性油墨废水处理过程中小颗粒水性油墨的去除效果。方法 模拟废纸碎浆体系中小颗粒水性油墨在不同助剂及不同pH条件下粒径的改变情况,从而得到不同助剂的使用效果。结果 添加一定量的无机助剂CaCl2、有机助剂CTAB或改变体系的pH值,均能增加无纤维时的水性油墨颗粒粒径;但纤维存在时CTAB并不能起到预期效果。结论 当体系pH值为5、CaCl2浓度为0.20 mol/L、CTAB浓度为0.12 mmol/L时,水性油墨颗粒的粒径相对较大,分别为3.8, 1.0, 0.5 μm;但当有纤维存在时,添加CaCl2的效果降低,最佳浓度是0.30 mol/L,粒径为2.7 μm;CTAB在纤维存在时并不能促进水性油墨的絮聚,反而会造成纸浆光学性能的降低。     

不同核结构复合胶乳的制备及压敏特性

采用半连续乳液聚合法制备了三种不同核结构的复合乳液:P(BA-co-AA)、PMMA/P(BA-co-AA)和MPS-SiO2/P(BA-co-AA)复合胶乳,乳液聚合反应转化率高,乳胶粒最终粒径控制得基本相同.将此三种乳液涂布在PET薄膜上,测定了核结构对压敏胶粘接性能(如初粘、180°剥离和耐剪切等)的影响.热失重分析、动态机械热分析表征了热性能和动态力学性能.结果表明,丙烯酸酯聚合物中加入纳米二氧化硅有助于改善其耐热性能,而压敏胶的耐剪切性能显著提高.     

原料颗粒度对BaTiO_3陶瓷晶粒大小及PTC效应的影响

通过研究原料颗粒度对 BaTiO_3 PTC 陶瓷晶粒大小的影响,提出并讨论了 BaCO_3和 TiO_2的固相反应模型。在生成 BaTiO_3的固相反应中,首先在 BaCO_3和 TiO_2颗粒之间生成少量 BaTiO_(?),隔离了 BaCO_(?)和 TiO_2的接触,从而阻止反应进行,但离子的扩散可使反应继续进行。在扩散过程中,Ba~(2+)的扩散为主,Ti~(4+)的扩散被抑制而可忽略。根据模型,生成的 BaTiO_3颗粒大小主要由 TiO_2原料的颗粒度决定,与 BaCO_3关系较小。所以 BaTiO_3陶瓷的晶粒大小及其 PTC 效应受 BaCO_3颗粒度的影响较小;在生产中为控制陶瓷晶粒大小,选择 TiO_2原料颗粒度是十分重要的,而 BaCO_3则次之。