防雾抗菌聚乙烯薄膜的制备及性能

目的 制备一种具有抗菌和防雾效果的改性薄膜.方法 防雾添加剂选择聚甘油脂肪酸酯(PGFE)和实验室自制的母粒(YS),抗菌剂选择丙酸钙(CP)和脱氢乙酸钠(以下称为DHA-S),将抗菌剂、防雾剂及PE粒子混合造粒,然后在流延机上流延得到防雾抗菌聚乙烯(PE)活性包装薄膜,并通过正交实验优化薄膜的制备配方.结果 与纯PE薄膜相比(抗张强度为8.64 MPa;质量分数为88.46％;断裂伸长率纵向为551.72％,横向为589.86％),添加YS(均以质量分数表示)(3％),PGFE(3％),DHA-S(1％)和CP(1％)的薄膜具有较好的防雾性、抗张强度(14.58 MPa)以及对试验菌较好的抗菌性能,但是薄膜透光率(82.68％)、断裂伸长率(纵向272.20％,横向140.20％)和阻隔性较差.结论 经过防雾剂和抗菌剂改性的聚乙烯薄膜,因其抗菌和防雾效果较好,以及其物理性能良好,可以作为食品包装材料使用.     

Interactions of Fullerene‐Polyglycerol Sulfates at Viral and Cellular Interfaces

Understanding the mechanism of interactions of nanomaterials at biointerfaces is a crucial issue to develop new antimicrobial vectors. In this work, a series of water‐soluble fullerene‐polyglycerol sulfates (FPS) with different fullerene/polymer weight ratios and varying numbers of polyglycerol sulfate branches are synthesized, characterized, and their interactions with two distinct surfaces displaying proteins involved in target cell recognition are investigated. The combination of polyanionic branches with a solvent exposed variable hydrophobic core in FPS proves to be superior to analogs possessing only one of these features in preventing interaction of vesicular stomatitis virus coat glycoprotein (VSV‐G) with baby hamster kidney cells serving as a model of host cell. Interference with L‐selectin‐ligand binding is dominated by the negative charge, which is studied by two assays: a competitive surface plasmon resonance (SPR)‐based inhibition assay and the leukocyte cell (NALM‐6) rolling on ligands under flow conditions. Due to possible intrinsic hydrophobic and electrostatic effects of synthesized compounds, pico‐ to nanomolar half maximal inhibitory concentrations (IC₅₀) are achieved. With their highly antiviral and anti‐inflammatory properties, together with good biocompatibility, FPS are promising candidates for the future development towards biomedical applications.     

Preferential Tumor Accumulation of Polyglycerol Functionalized Nanodiamond Conjugated with Cyanine Dye Leading to Near‐Infrared Fluorescence In Vivo Tumor Imaging

Preferential accumulation of nanoparticles in a tumor is realized commonly by combined effects of active and passive targeting. However, passive targeting based on an enhanced permeation and retention (EPR) effect is not sufficient to observe clear tumor fluorescence images in most of the in vivo experiments using tumor‐bearing mice. Herein, polyglycerol‐functionalized nanodiamonds (ND‐PG) conjugated with cyanine dye (Cy7) are synthesized and it is found that the resulting ND‐PG‐Cy7 is preferentially accumulated in the tumor, giving clear fluorescence in in vivo and ex vivo fluorescence images. One of the plausible reasons is the longer in vivo blood circulation time of ND‐PG‐Cy7 (half‐life: 58 h determined by the pharmacokinetic analysis) than that of other nanoparticles (half‐life: <20 h in most of the previous reports). In a typical example, the fluorescence intensity of tumors increases due to continuous tumor accumulation of ND‐PG‐Cy7, even more than one week postinjection. This may be owing to the stealth effect of PG that was reported previously, avoiding recognition and excretion by reticuloendothelial cells, which are abundant in liver and spleen. In fact, the fluorescence intensities from the liver and spleen is similar to those from other organs, while the tumor exhibits much stronger fluorescence in the ex vivo image.     

Synthesis of poly(glycerol methacrylate) and its application to dimensional stabilization of wood

The dimensional stabilization of wood is investigated using poly(glycerol methacrylate) (PGMA) prepared from polyglycerol and glycidyl methacrylate instead of the well‐known poly(ethylene glycol). PGMA allows waterborne treatment of wood, which after polymerization leads to the formation of a wood polymer composite with improved dimensional stability. Microscopic observations and a picture analysis permit the location of PGMA in the wood cell walls and explains the dimensional stabilization by its bulking effect. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 743–749, 2003     

Synthesis,Reductive Cleavage,and Cellular Interaction Studies of Biodegradable,Polyglycerol Nanogels

In this paper we describe disulfide containing, polyglycerol nanogels as a new class of biodegradable materials. These nanoparticles are prepared in inverse miniemulsion via an acid catalyzed ring‐opening polyaddition of disulfide containing polyols and polyepoxides. Varying conditions allow us to tune particle size and disulfide content within the polymer network; particles can be prepared with narrow polydispersities and diameters in the range from 25 to 350 nm. Particle degradation under reductive intracellular conditions is studied by various analytical techniques. Gel permeation chromatography indicates that final degradation products have relatively low molecular weights (≤ 5 kDa). In addition, studies in cell culture show these nanoscale materials to be highly biocompatible. Dye‐labelled nanogels are shown by optical microscopy techniques to readily internalize into cells by endocytotic mechanisms. This study highlights the great potential of these particles to function as sophisticated nanotransporters that deliver cargo to a certain tissue or cell target and then biodegrade into smaller fragments which would be cleared from the body by the kidney. (with ≈ 30 kDa molecular weight cut off)     

Ether-Based Muds Show Promise for Replacing Some Oil-Based Muds

Two different polyethers were evaluated for their potential use in drilling fluids as a base fluid for synthetic ether-based mud, which is one type of synthetic-based drilling fluid that are used when drilling for oil and gas by a rotary method and they have several technological and environmental advantages over oil-based mud. Polyglycerol or polytriethanolamine, which derive from the condensation reaction of glycerol or triethanolamine was used as a base fluid in the formulation of ether-based mud in comparison with oil based mud. The evaluation includes the study of rheology, filtration properties, electrical stability, and thermal stability for oil-based mud and synthetic ether-based mud, which are formulated of polyglycerol or polytriethanolamine. The result show that the tested synthetic ether-based mud are more viscous at low temperature, thin more with increasing temperature, and have high thermal stability than oil-based mud. Biodegradation of the mud formulated with polyglycerol or polytriethanolamine was also studied.     

The effects of adding water and polyglycerol polyricinoleate on the texture,appearance, and sensory qualities of compound milk chocolate

Water and polyglycerol polyricinoleate (PGPR) contents were varied to investigate the effects of these parameters on the textural properties, surface color, and sensory qualities of compound chocolates. The content levels of water and PGPR were manipulated between 3–10 and 0.3–3.3%, respectively (content expressed as % by weight of finished product). Simultaneous variations in water and PGPR levels, especially in high ratios, resulted in a drastic reduction in the hardness values (p<0.001), darker color (p<0.01), and an unusual taste (p<0.05) but the effect of water addition was more pronounced than PGPR. It was observed that compound chocolates with 3% water content were not dissimilar from the control with respect to all properties. In the samples of the same water content, the effect of PGPR addition was nearly insignificant. For these confectionaries, the best proportion of ingredients for producing water‐containing compound chocolate was considered the one which has the least negative effects on bloom surface area and the texture. Practical applications: Manufacturing water‐containing imitation chocolates represent a general approach for adding all water‐base materials to chocolate such as cream, yogurt, milk, etc. or water‐soluble substances like trace elements and vitamins. Conventional chocolates become soft at above 28°C, and lose shape retention at above 32°C. Water addition provides a heat‐resistance compound chocolate with shape retention at a temperature above 40°C, being not sticky to the direct touch. However, there has been very limited information about water addition's effects on the chocolate structure. In order to be able to predict the structural variations, it is important to study how water affects the physical properties of the chocolates.     

固体碱催化合成中碳链脂肪酸聚甘油酯

以聚甘油、樟树籽仁油脂肪酸为原料,固体碱KOH/Al2O3为催化剂,催化酯化合成中碳链脂肪酸聚甘油酯.采用单因素试验研究反应温度、反应时间、聚甘油与中碳链脂肪酸质量比、催化剂用量对酯化率的影响,通过正交试验优化中碳链脂肪酸聚甘油酯的合成工艺.最优合成工艺条件为反应温度220℃、反应时间2.5h、聚甘油与中碳链脂肪酸质量比2∶1、催化剂用量4.5％,该条件下酯化率为87.5％,所得中碳链脂肪酸聚甘油酯的酸值(KOH)、皂化值(KOH)、碘值(Ⅰ)、熔点分别为1.86 mg/g、148.4 mg/g、2.9 g/100 g、47.3℃.