环氧树脂微粒化水基化体系

本文系统介绍了环氧树脂微粒化水基化体系的特点及用途，制备方法和反映体系特性的一些重要参数。     

Spherical Polyolefin Particles from Olefin Polymerization in the Confined Geometry of Porous Hollow Silica Particles

Porous hollow silica particles (HSPs) are presented as new templates to control the product morphology in metallocene‐catalyzed olefin polymerization. By selectively immobilizing catalysts inside the micrometer‐sized porous hollow silica particles, the high hydraulic forces resulting from polymer growth within the confined geometries of the HSPs cause its supporting shell to break up from the inside. As the shape of the support is replicated during olefin polymerization, perfectly spherical product particles with very narrow size distribution can be achieved by using HSPs exhibiting a monomodal size distribution. Furthermore, the size of the obtained product particles can be controlled not only by the polymerization time but also by the size of the support material.

     

TiO2微粒功能化多孔Al2O3膜的光电化学研究

用恒电位法制备了多孔Al2O3薄膜,通过在Al2O3薄膜孔内水蒸汽水解钛酸异丙酯生成了锐钛矿型TiO2微粒,制备出了Al2O3与TiO2微粒的复合薄膜．用XRD,SEM,光电化学方法进行了研究．实验表明：该复合薄膜具有光电转换特性,在光催化、光电化学太阳能转换中具有应用价值．     

Sintered and 3D-Printed Bulks of MgB2-Based Materials with Antimicrobial Properties

Pristine high-density bulk disks of MgB₂ with added hexagonal BN (10 wt.%) were prepared using spark plasma sintering. The BN-added samples are machinable by chipping them into desired geometries. Complex shapes of different sizes can also be obtained by the 3D printing of polylactic acid filaments embedded with MgB₂ powder particles (10 wt.%). Our present work aims to assess antimicrobial activity quantified as viable cells (CFU/mL) vs. time of sintered and 3D-printed materials. In vitro antimicrobial tests were performed against the bacterial strains Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 25923, Enterococcus faecium DSM 13590, and Enterococcus faecalis ATCC 29212; and the yeast strain Candida parapsilosis ATCC 22019. The antimicrobial effects were found to depend on the tested samples and microbes, with E. faecium being the most resistant and E. coli the most susceptible.     

高分子多孔微球产品的制备及其在类病毒颗粒分离纯化中的应用

高分子多孔微球在医药领域的分离纯化中应用广泛,是重要的化工产品。高分子多孔微球的形成是一个复杂的过程,利用聚合物与有机溶剂致孔剂的相分离,可得到小于100 nm孔径的多孔微球;而水和疏水性聚合物之间相分离程度远大于有机溶剂与聚合物间的相分离程度,因此可获得大于100 nm孔径的多孔微球。针对不同应用领域选择不同的方法,设计并制备出合理的微球结构,对多孔微球的实际应用十分关键。本综述介绍了纳孔、介孔、大孔微球产品的制备方法悬浮聚合和种子聚合法,重点介绍本课题组制备超大孔微球的方法--反胶团溶胀法和W/O/W复乳法,上述两种方法解决了常规方法难以制备大孔径微球产品的问题,拓展了多孔微球在类病毒颗粒等大尺寸蛋白分离纯化领域的应用。在此基础上,以HB-VLPs为模型对比了不同孔径微球对类病毒颗粒吸附量、回收率、结构、以及纯化效果的差异,揭示超大孔微球产品在类病毒颗粒分离纯化中的优势。     

Blocking Ability and Flow Characteristics of Nitrogen Foam Stabilized with Clay Particles in Porous Media

Particles-stabilized foams have received more attention in recent years due to their specific characteristics and advantages in contrast to conventional foams which were stabilized with surfactants. However, the rheology of particles-stabilized foam in consolidated cores was rarely studied. To investigate the feasibility of the particles-stabilized foam application in enhanced oil recovery, the blocking ability and flowing characteristics of foam stabilized with clay particles were investigated by using experimental cores. To do this, the foam resistance factor was studied as an index in this article. The effects of foam quality (gas velocity divided by total velocity), injection rate of foam, and the permeability of cores on the blocking ability of foams were investigated. Results showed that the blocking ability reached the peak value at the foam quality of 0.74. This indicated effective blocking ability as conventional foams performed in porous media. Moreover, the foams block the channels more effectively in high permeability cores, compared with low permeability ones. Finally, foams displayed shear-thinning property in porous media as injection rate increased.      

In Vitro Tests of FDM 3D-Printed Diclofenac Sodium-Containing Implants

One of the most promising emerging innovations in personalized medication is based on 3D printing technology. For use as authorized medications, 3D-printed products require different in vitro tests, including dissolution and biocompatibility investigations. Our objective was to manufacture implantable drug delivery systems using fused deposition modeling, and in vitro tests were performed for the assessment of these products. Polylactic acid, antibacterial polylactic acid, polyethylene terephthalate glycol, and poly(methyl methacrylate) filaments were selected, and samples with 16, 19, or 22 mm diameters and 0%, 5%, 10%, or 15% infill percentages were produced. The dissolution test was performed by a USP dissolution apparatus 1. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide dye (MTT)-based prolonged cytotoxicity test was performed on Caco-2 cells to certify the cytocompatibility properties. The implantable drug delivery systems were characterized by thermogravimetric and heatflow assay, contact angle measurement, scanning electron microscopy, microcomputed tomography, and Raman spectroscopy. Based on our results, it can be stated that the samples are considered nontoxic. The dissolution profiles are influenced by the material properties of the polymers, the diameter, and the infill percentage. Our results confirm the potential of fused deposition modeling (FDM) 3D printing for the manufacturing of different implantable drug delivery systems in personalized medicine and may be applied during surgical interventions.     

P(St-EAE-MAA)共聚物多孔微球的合成

利用无皂种子乳液聚合法合成了以聚苯乙烯(St)为骨架、丙烯酸乙酯(EA)和甲基丙烯酸(MAA)为共聚单体的P(St-EA-MAA)共聚物乳液;乳液经碱酸分步处理法制得共聚物多孔微球.考查了MAA用量和碱酸处理温度对微球形态的影响.     

Fabrication of Porous Polyimide Membrane with Through-Hole via Multiple Solvent Displacement Method

Porous polyimide (PI) membranes are widely used in separation processes because of their excellent thermal and mechanical properties. However, the applications of porous PI membranes are limited in the nanofiltration range. In this study, porous PI membranes with through-holes have been successfully fabricated by the novel multiple solvent displacement method. This new method requires only a porous polyamic acid (PAA) membrane, which was prepared by immersing PAA film in N-methylpyrrolidoneebk; (NMP) prior to immersing it in a mixed solvent consisting of NMP and a poor solvent, followed by immersion only in poor solvent. The pore size, morphology, porosity, and air permeability demonstrated that the fabricated PI membranes had a uniformly porous structure with through-holes over their surface. This new method enabled control of pore size (3–11 μm) by selecting a suitable poor solvent. This multiple solvent displacement method is highly versatile and promising for the fabrication of porous PI membranes.     

A New Metal-Organic Framework: Product of Solvothermal Synthesis in 3D-Printed Autoclaves

Russian Journal of Coordination Chemistry - A new metal-organic framework {Zn4(BDC)3(OAc)2(DMF)4} (BDC = terephthalate anion) was synthesized under solvothermal conditions in a 3D-printed...     

TiO2微粒功能化多孔Al2O3膜的光电化学研究

用恒电位法制备了多孔Al₂O₃薄膜, 通过在Al₂O₃薄膜孔内水蒸汽水解钛酸异丙酯生成了锐钛矿型TiO₂微粒, 制备出了Al₂O₃与TiO₂微粒的复合薄膜. 用XRD, SEM, 光电化学方法进行了研究. 实验表明: 该复合薄膜具有光电转换特性, 在光催化、光电化学太阳能转换中具有应用价值.     

Effect of Temperature on the Electrorheological Behavior of Porous Chitosan Particles in Polydimethylsiloxane

Doklady Physical Chemistry - The rheological behavior of a 1 wt % suspension of highly porous chitosan particles in polydimethylsiloxane in a high electric field has been studied as a function of...     

Simultaneous Identification of Spectral Properties and Sizes of Multiple Particles in Solution with Subnanometer Resolution

We report an unsurpassed solution characterization technique based on analytical ultracentrifugation, which demonstrates exceptional potential for resolving particle sizes in solution with sub‐nm resolution. We achieve this improvement in resolution by simultaneously measuring UV/Vis spectra while hydrodynamically separating individual components in the mixture. By equipping an analytical ultracentrifuge with a novel multi‐wavelength detector, we are adding a new spectral discovery dimension to traditional hydrodynamic characterization, and amplify the information obtained by orders of magnitude. We demonstrate the power of this technique by characterizing unpurified CdTe nanoparticle samples, avoiding tedious and often impossible purification and fractionation of nanoparticles into apparently monodisperse fractions. With this approach, we have for the first time identified the pure spectral properties and band‐gap positions of discrete species present in the CdTe mixture.     

多组分多出口稀土串级萃取静态优化设计研究(I)静态设计算法

研究了多组分、多出口稀土串级萃取体系静态优化设计过程的精确计算方法. 首先推导出串级萃取体系最重要的物料平衡和萃取平衡关系, 其次根据分离要求等条件确定了各出口的相对流量, 利用萃取平衡和物料平衡关系进行静态递推, 并在求解过程中根据物料平衡关系引入了校正参数, 通过对递推结果的迭代校正, 最终得到收敛的计算结果, 解决了静态设计算法的关键问题. 这一方法为多组分多出口稀土串级萃取过程的静态优化设计提供了精确算法.     

Computer Simulation of the Structure of Porous Electrodes with an Immobilized Enzyme and Nanosized Support Particles

The efficiency of the operation of a porous electrode with an immobilized enzyme is defined, in particular, by a lucky structure of its active layer, which can contain nanosized particles of the support. The composites of such a kind are prepared with the aid of methods of colloidal chemistry. The aim of this particular investigation is to perform a computer simulation of processes of coagulation of particles of the support and their possible heterocoagulation with molecules of the enzyme. Algorithms of the formation of nanocomposite structures in solution are suggested. Calculations show that the concentration of the enzyme molecules in the nanocomposite structures cannot exceed a certain critical value. On the other hand, at a fixed value of the concentration of the enzyme molecules, the concentration of the support particles must not fall below a certain threshold quantity, which provides for the passing of current through the active layer. In order for all the enzyme molecules, rather than for a fraction of these, in the composite to take part in the process of bioelectrocatalysis, the concentration of support particles must be increased even higher, to an optimum value.__________Translated from Elektrokhimiya, Vol. 41, No. 6, 2005, pp. 738–747.Original Russian Text Copyright © 2005 by Chirkov, Rostokin.     

高羧基含量无皂多孔聚合物乳胶粒的研究

功能性聚合物乳液的性能与其功能基的含量密切相关. 采用完全无皂种子乳液聚合技术合成了具有不同羧基含量并且粒径分布均一的交联型聚甲基丙烯酸甲酯-丙烯酸乙酯因为甲基丙烯酸 [P(MMA-EA-MAA)]乳胶粒, 然后通过碱后处理, 制备出了高羧基含量的无皂多孔P(MMA-EA-MAA)乳胶粒. 系统研究了MAA对聚合反应、胶粒特性及胶粒多孔结构形态的影响. 结果表明: 在交联剂二乙烯基苯用量一定(0.3 g)的条件下, 随着MAA用量从4.0 mol%增加到 10.0 mol%, 聚合物交联程度(P_x)从28.26%迅速增大至90.95%, 当其用量超过10.0 mol%后P_x增大趋势变缓; 随着MAA用量的增加, 处理后胶粒体积膨胀百分率(ΔV)逐渐增大, 在MAA用量为12.0 mol%时ΔV达到42.1%的最大值, 当MAA用量增大到14.0 mol%时, 尽管P_x高达95.44%, 胶粒仍具有完好的孔状结构.     

特殊形貌SrCO3粒子的简易合成

在纯水介质中通过简单调节SrCO3浓度合成了均一的橄榄状SrCO3粒子和由针状 SrCO3粒子向两端辐射而成的束状聚集体。聚甲基丙烯酸钠（PMAA）的存在有着使 SrCO3粒子形貌由束状聚集体逐渐变得两端钝化且膨胀的趋势，在适当条件下可得 到较为均一的花生状、球状和树枝状SrCO3粒子。     

特殊形貌SrCO_3粒子的简易合成

在纯水介质中通过简单调节SrCO3浓度合成出了均一的橄榄状SrCO3粒子和由针状SrCO3粒子向两端辐射而成的束状聚集体.聚甲基丙烯酸钠(PMAA)的存在有着使SrCO3粒子形貌由束状聚集体逐渐变得两端钝化且膨胀的趋势,在适当条件下可得到较为均一的花生状、球状和树枝状SrCO3粒子     

Synthesis of Latex Particles with Surface Functional Groups and Their Applications for the Fabrication of Porous Materials

In this study, monodisperse latex particles with specific surface functional groups were synthesized by emulsifier-free emulsion polymerization. Amidine or carboxylated polystyrene nanospheres with narrow size distribution were prepared by emulsion polymerization using AIBA (α,α′-zodiisobutyramidine dihydrochloride) as amine-containing initiator or acrylic acid as carboxyl-containing comonomer, respectively. Factors affecting the particle size and distribution were systemically studied by changing the amount of initiator or monomer, the polymerization temperature, and the stirring speed of emulsion polymerization reactor. Monodisperse polymethylmethacrylate beads were also synthesized by soapless emulsion polymerization using methacrylic acid or aminoethylmethacrylate hydrogen hydrochloride as comonomer for the surface functionalization of the particles. As applications of the latex beads, the polymeric particles were adopted as templating materials for the fabrication of macroporous titania film and meso-macroporous silica particles by colloidal templating method.     

X‐Ray Tomography Imaging of Porous Polyolefin Particles in an Electron Microscope

Advanced models of penetrant transport and reaction in spatially 3D porous polyolefin particles reconstructed from X‐ray µCT images require proper determination of particle morphology. Moreover, polyolefins exhibit a relatively low absorptivity for X‐rays, therefore their investigation using µCT can be difficult. In this paper, a low‐resolution µCT built into an SEM is used to examine how the µCT resolution and several user‐selected parameters associated with the scanning/reconstruction affect the resulting particle morphology. Using samples with known morphology and independent imaging techniques, the performance of the µCT device is critically assessed. Finally, a method suitable for the reliable reconstruction of polyolefin particles using low‐resolution µCT is proposed.