聚合物

Abstract(#br)In nanoindentation tests for soft polymers, the elastic modulus estimated from the Hertz model varies with applied force, implying the effect of adhesion work needs to be considered in contact theory. In this article, a hybrid method of combining the Hertz model and the Johnson–Kendall–Roberts (JKR) model is presented, to analytically explain the descending phenomenon of the modulus estimation by considering adhesive effects.

Abstract(#br)We will describe the use of an alternative polymer which is suitable for use in microfluidic applications which require the use of harsh chemicals or aggressive solvents. Currently microfluidics systems are mainly manufactured in polydimethylsiloxane (PDMS) due to its ease of use, and the ability to produce monolithic microfluidic valves directly into the same material as the microfluidic chip.

Abstract(#br)Interaction between differentiating neural stem cells and the extracellular environment guides the establishment of cell polarity during nervous system development. Developing neurons read the physical properties of the local substrate in a contact-dependent manner and retrieve essential guidance cues. To restore damage brain area by tissue engineering, the biomaterial scaffold has to mimic this microenvironment to allow organized tissue regeneration.

Abstract(#br)In effort to investigate the influence of the micro/nano-patterning or surface texturing on the nanotribological properties of patterned surfaces, the patterned polydimethylsiloxane (PDMS) surfaces with pillars were fabricated by replica molding technique. The surface morphologies of patterned PDMS surfaces with varying pillar sizes and spacing between pillars were characterized by atomic force microscope (AFM) and scanning electron microscope (SEM). The AFM/FFM was used to acquire the friction force images of micro/nano-patterned surfaces using a colloidal probe.

Abstract(#br)In this study, nanomechanical properties of a variety of polymeric materials was investigated by means of AFM. In particular, selecting different AFM probes, poly(methyl methacrylate) (PMMA), polydimethylsiloxane (PDMS) bulk samples, sol–gel hybrid thin films and hydrated hyaluronic acid hydrogels were indented in air to determine the elastic modulus. The force–distance curves and the indentation data were found to be greatly affected by the cantilever stiffness and by tip geometry.

Abstract(#br)All-solution-processed, easily-made, flexible multi-walled carbon nanotube (MWCNT)/polydimethylsiloxane (PDMS)-based electrodes were fabricated and used for electrochemical DNA sensors. These electrodes could serve as a recognition layer for DNA, without any surface modification, through π–π interactions between the MWCNTs and DNA, greatly simplifying the fabrication process for DNA sensors.

Abstract(#br)This work investigated the application of vacuum ultraviolet (VUV) irradiation to the bonding of various substrates, including glass, polycarbonate (PC), cyclic olefin polymer (COP), polydimethylsiloxane (PDMS) and polymethyl methacrylate (PMMA). This method has the advantage of being able to bond various substrates without the application of heat or adhesives, and therefore may be very useful in the fabrication of micro/nanoscale structures composed of polymers.

Abstract(#br)The phase equilibria and saturated fluid properties of CO 2 + PDMS (polydimethylsiloxane) systems were measured to investigate suitability for future hydrodynamic experiments. Two PDMS fluids graded at 100 cSt (M w = 14 300, M z = 22 000, Đ M = 1.59) and 200 cSt (M w = 18 400, M z = 53 000, Đ M = 4.72) were selected. Saturation pressure, and hence phase transition pressure, was determined for 1–70 wt% PDMS in CO 2 at 313–353 K using the variable volume view cell method (SynVisVar).

文摘( # br )从非极性液体混合物中分离水(脱水)是一个具有挑战性的问题，但在石油工业和动力冷却剂等领域却是一个重要的问题。我们描述了一种基于聚二甲基硅氧烷( PDMS )的大容量亲水性海绵的制备方法和性能。通过在前驱体PDMS液体中加入1 -辛醇并加入氯化锌粉末模板，然后在115℃下加热固化，然后洗脱模板得到海绵。所制备的PDMS海绵的吸水性能达到约1600 %，比通常所说的脱水吸附剂高2倍。这些高容量可能被用作石油、碳氢化合物和其他非极性液体的脱水剂。

文摘( # br )通过亲水丙烯酰胺单体和疏水PDMS-IPDI-HEMA大分子单体在水溶液中的胶束共聚合反应，设计并制备了一种具有可调透氧性的新型聚二甲基硅氧烷( PDMS )水凝胶。对制备的水凝胶的形貌、化学成分和透氧性( Dk )进行了研究，并验证了其透氧性随着PDMS - IPDI - HEMA含量的增加而逐渐增加。因此，本工作为用环境友好的方法生产一类不使用有机溶剂的含有PDMS的水凝胶开辟了新的途径。