超临界流体辅助挤出微孔塑料的研究

介绍了超临界流体的基本性质;并就其在制备聚合物微孔塑料中的应用进行综述;主要介绍了连续挤出法制备微孔塑料。     

超临界流体技术在聚合物加工中的应用

简要介绍了超临界二氧化碳的性质及其在聚合物科学中的应用优势，结合目前国内外超临界流体技术在聚合物加工中应用的最新进展，重点介绍了超临界流体技术在聚合物结晶，发泡聚合物的制备，共混聚合物的加工和共混聚合物膜的相分离中的应用。     

超临界CO2流体工艺用于制备多孔分离膜的研究进展

介绍了超临界CO2流体用于微孔分离膜制备机理;分析了压力、聚合物浓度及温度等条件对膜孔结构的影响;论述了CO2对聚合物增塑作用的大小和CO2在聚合物材料中向外扩散的速率是最终影响膜孔结构形态的两个基本因素;综述了超临界CO2流体用于分离膜的制备的独特优势.     

超临界流体制备聚合物微孔材料技术研究进展

上世纪90年代，超临界流体(SCF)制备聚合物微孔材料实现了工业化，这种方法制备的微孔材料具有非常多的优点，被誉为是“21世纪的新型材料”。本文首先介绍了SCF的概念、性质，以及其在相关领域的应用情况。然后对采用SCF制备聚合物微孔材料的理论研究进展进行了介绍，主要讨论了在聚合物中的溶解行为、微孔的形成和长大机理以及聚合物／SCF体系的流变行为等三个方面的研究内容。本文还介绍了采用SCF制备聚合物微孔材料的应用研究进展，探讨了非连续方法和连续方法的发展过程，并重点对连续成型方法的设备进行了介绍。     

超临界流体技术制备生物可降解聚合物/药物纳米微粒研究进展

生物可降解聚合物/药物纳米微粒在药物靶向递送、有效成分封装和医疗诊断等领域具有突出的优势。超临界流体超细微粒制备技术具有绿色环保、制备方法种类多、粒径易调节和后续分离纯化容易等特点,得到了广泛的研究。为了得到满足使用要求的聚合物/药物纳米微粒,超临界流体制粒技术是有效的手段之一。论述了生物可降解聚合物纳米材料的特点和应用情况,简要介绍了超临界流体及特性,重点介绍了超临界溶液快速膨胀(RESS)、超临界抗溶剂沉淀(SAS)、超临界CO₂辅助雾化(SAA)和超临界流体乳液萃取(SFEE)的工艺特点、制备方法、基本原理和研究进展,并对超临界流体技术制备聚合物/药物纳米微粒的发展方向进行了展望。     

浅析超临界CO2在连续挤出微孔塑料中的应用

超临界流体（简称SCF）技术已广泛应用于分离、反应、材料加工、生物技术以及环境保护等领域，其中在材料加工中的应用包括塑料的分解回收，聚合物微粒制备，聚合物的增塑、改性及功能化等。而以SCF作发泡剂制备聚合物微孔材料也是SCF技术应用的一个重要方向。采用此方法制得的微孔塑料的冲击韧性、刚性及耐久性均比未发泡塑料及普通发泡塑料显著提高。     

超临界流体微孔发泡塑料的研究进展

将超临界流体技术与微孔发泡技术结合,阐述了制备微孔发泡塑料常用的几种方法(间歇成型法、连续挤出法及注射成型法),比较了几种方法各自的优缺点。同时,介绍了微孔发泡塑料的研究现状及发展趋势,最后分析了利用超临界流体作为发泡剂的优势及两种技术结合后所带来的成果及挑战。     

超临界流体技术在聚合物中的应用

介绍了超临界流体技术在聚合物中的应用，结合目前国内外超临界流体技术在聚合物加工中的最新进展，重点介绍了超临界流体在聚合物解聚、聚合物纯化、聚合物合成和聚合物发泡材料中的应用。     

超临界二氧化碳在工业上的应用

超临界二氧化碳具有其他超临界流体不可比拟的优势，因此，引起了研究者广泛的兴趣。本文简单的介绍了超临界二氧化碳的优点，如具有两极性、良好的流动性和扩散性等。综述了超临界二氧化碳在降低高分子聚合物粘度中的应用以及在制备微孔塑料中应用、原理和研究进展，超临界二氧化碳作为绿色的介质，将会有更广阔的应用价值。     

超临界流体在聚苯乙烯制备中的应用

综述了超临界流体在聚苯乙烯(PS)制备中的应用。超临界流体分级能方便地通过调节温度和压力对溶解度进行控制。获得相对分子质量分布较窄的PS级分;采用超临界流体可以连续稳定地制备纯度高和粒径分布均匀的微细PS;运用超临界溶液快速膨胀技术制得了微粒形态良好、粒径分布较窄的微米级PS微粒;采用超临界气体制备的微孔发泡PS复合材料具有较高的机械强度和性价比;PS超临界流体脱挥分具有能耗低、传质效率高的特点,而且不会引起聚合物的降解;使用超临界流体制备PS复合材料成为人们关注的研究热点。     

Establishing a three‐dimensional diagram with solubility parameter representing the general behavior of crystallization for amorphous poly(ethylene 2,6‐naphthalate)

Supercritical fluids having different solubility parameters were obtained by changing the parameters of supercritical CO₂ and adding a cosolvent (methanol). The crystallization behavior of amorphous poly(ethylene 2,6‐naphthalate) (PEN) in these supercritical fluids covering a wide range of solubility parameter was investigated using wide‐angle X‐ray diffraction and differential scanning calorimetry. A three‐dimensional diagram of crystallization versus temperature, pressure and solubility parameter (i.e. solvent concentration) was established to represent the general behavior of crystallization for amorphous PEN. Supercritical fluids with a higher overall solubility parameter plasticized the PEN chains more effectively and thus provided moderate conditions to induce the crystallization of amorphous PEN. Copyright © 2007 Society of Chemical Industry     

超临界流体技术在环保领域中的应用

综述了超临界流体中的化学反应、超临界流体萃取、超临界流体色谱在废弃物处理、清洁生产和环境分析等方面的应用。     

Heterogeneous Catalysis in Supercritical Media: 1. Carbon Dioxide

Over the past few years, supercritical fluids have received considerable interest as reaction media. Supercritical fluids combine properties of gases and liquids. Densities are lower than in the liquid phase, but significantly higher than in the gas phase. This makes supercritical fluids excellent solvents for a variety of substances. The good dissolution capacity exists only in or near the supercritical range. Reaction products can be separated, for instance, simply by decreasing temperature and pressure. This may be used to intensify the process as complex separation processes, like distillation, are avoided.     

生物材料制备新方法--超临界流体技术

虽然超临界流体技术的应用领域越来越广,但是在生物材料研究开发领域中的应用只是近几年的事。结合作者已开展的研究工作,阐述了超临界流体在生物材料加工、缓释控释药物制备、组织工程支架材料的成型以及异种骨移植前处理等方面的一些运用,对超临界流体技术在生物材料中的运用提出了一些新看法。     

Prediction of Diffusion Coefficients of Liquid and Solid Solutes in Supercritical Solvents

1 INTRODUCTIONSupercritical fluids have found new and increasing applications in the past decade.Theirunique properties of low viscosity,high diffusivity and adjustable solvency have favored theiremployment as solvents in chemical reactions and extraction processes.Proper evaluation ofthe technical feasibility for supercritical fluids in these processes would involve the hydrody-namic and mass-transfer parameters,the estimation of which calls for reliable molecular dif-fusion coefficients of various solutes in the supercritical fluid of interest.Therefore,it follows     

Novel Process Options for Application of Zeolites in Supercritical Fluids and Ionic Liquids

Supercritical fluids and ionic liquids offer attractive opportunities for modifying and applying zeolites as adsorbents and catalysts. After a brief introduction to the most important properties of these solvents, examples of zeolite applications in supercritical fluids and ionic liquids from the recent literature are discussed. Particular emphasis is put on the influence of reaction media on the processes occurring in the zeolitic pore systems, e.g., during shape‐selective conversions in zeolite catalysts. The present potential and future challenges for the application of zeolites in supercritical fluids and ionic liquids are identified. Most attractive process options arise from a combined use of both ionic liquids and supercritical fluids in integrated reaction schemes.     

超临界流体技术及其在生物工程中的应用

介绍了在生物工程有着广泛的应用前景的多种超临界流体技术，包括提取生物活性物质的超临界流体萃取，超临界条件二氧化碳中制备手性药物制备和淀粉水解制取葡萄糖的非水酶催化反应，超临界水条件下纤维素水解制备葡萄糖，超临界流体中的细胞破碎，制备缓释药物和色说载体的超临界流体溶液快速膨胀和气体抗溶剂结晶和沉淀技术。     

微发泡弹性体材料的研究进展

微发泡弹性体材料是一种重要的高分子材料，它有其独特的微孔结构能够满足多方面的需要，因此也成为近来一段时间研究的热点。本文综述了其微孔成型机理及其制备微发泡弹性体材料的几个重要的方面即发泡剂的选择、发泡助剂的选择及交联过程和发泡过程的匹配，通过恰当的控制这几个方面，可以制得性能良好的微发泡弹性体材料。     

Fabrication of polyamide 12T micro-cellular foams with ultra-high compressive strength via in situ polytetrafluoroethylene fibrillation using supercritical carbon dioxide foaming

The development of micro-cellular foams with ultra-high compressive strength and high volume expansion ratio (VER) is a challenging task. Herein, polyamide 12T (PA12T) micro-cellular foams with ultra-high compressive strength were fabricated via in situ polytetrafluoroethylene (PTFE) fibrillation using supercritical CO₂ foaming technology and a chain extender. The resulting branched structure showed considerably improved viscoelasticity and foaming performance, thus improving the cell morphology of the PA12T foam and exhibiting high VER. The PTFE fibrillation network induced melt strength enhancement, crystallization nucleation, and cell nucleation. The branched PA12T foam with 1.5 wt% PTFE exhibited the smallest cell diameter (15 μm) and highest cell density (3 × 10⁹ cells/cm³). The compressive strength of the foam (0.50 MPa under 5% strain) was 70% higher than that of pure PA12T. This research offers an effective method for producing high-VER PA12T foams with adjustable micro-cellular structures and excellent mechanical properties.     

A general relation for identifying the liquid like and vapour like regions of supercritical fluids

Supercritical fluids exhibit liquid like behaviour close to a reduced pressure and reduced temperature of 1.0. The density of a supercritical fluid in this region is similar to that of liquids. Many practical applications use the sharp change from liquid like properties to vapour like properties for a variety of uses. There is no correlation in the literature that gives the general locus of the region that separates vapour like and liquid like regions of super critical fluids. In this article, we present a generalized correlation based on the acentric factor, and calculations obtained using NIST REFPROP.