聚二甲基硅氧烷

Abstract(#br)Poly(dimethylsiloxane–urethane) (PDMS–PU) nanocomposite membranes with various concentrations of polyhedral oligomeric silsesquioxanes (POSS) were synthesised and the influence of POSS molecules on gas transport properties was studied. In this, two different types of POSS nanoparticles such as CyPOSS and POSS-H were incorporated and their effect on permeation properties was studied. Nanocomposite membranes were characterized using DSC, AFM, XRD and contact angle measurements.

Abstract(#br)Mixed matrix membranes were prepared by incorporating ZSM-5 zeolite particles into polydimethylsiloxane. A uniform dispersion of the zeolite in the membrane was obtained. The membranes were characterized with scanning electron microscopy, and the effects of zeolite loading on membrane performance were evaluated. It was found that 80\u003cce:hsp sp=\"0.25\"/\u003ewt.% ZSM-5 loading was optimal for selectivity.

Abstract(#br)The permeation tubes were fabricated using polydimethylsiloxane (PDMS) and their permeation behaviour of water vapour was investigated under different experimental conditions. Experimental results showed that the permeation rate through PDMS wall was largely dependent on tube material and temperature. Permeation rate of water through PDMS shows approximately 100 times higher than that of tetrafluoroethylene–hexafluoropropylene copolymer. High concentration of standard water vapour can be made due to their superior permeation rate.

Abstract(#br)We present leakage-free valves and an efficient fixed-volume mixer fabricated using a four-layer soft lithography technique in polydimethylsiloxane (PDMS). Mixing is achieved with a 95% efficiency in a few seconds by creating circular flow patterns inside a simple rectangular chamber. Pressurized air is used to actuate control chambers for active valving and mixing. In our device, neither the mold nor the microfluidic channel requires complex designs.

Abstract(#br)Synthesis and properties of semi-interpenetrating polymer networks (semi-IPNs) based on polydimethylsiloxane (PDMS)/poly(ethylene glycol) (PEG)-modified chitosan were studied. 1–20\u003cce:hsp sp=\"0.25\"/\u003ewt% of PDMS or PEG was interpenetrated into chitosan hydrogels having 10\u003cce:hsp sp=\"0.25\"/\u003ewt% of hexamethylene-1,6-di-(aminocarboxysulfonate) (HDA) as a water-soluble crosslinker.

ˆﰀ缘枠ﰅ缘

Abstract(#br)We present a microfluidic chip for cell handling applications fabricated in polydimethylsiloxane (PDMS). The chip was designed to accumulate cells inside a reaction chamber where they can be manipulated under attendance of a liquid reagent (PEG–polyethylene glycol) for cell fusion. To enable the cell handling a fluid management system was developed which includes pneumatically actuated microfluidic valves integrated into the chip. Various valve geometries were simulated in ANSYS and characterized in a series of tests to identify a feasible valve concept.

Abstract(#br)This study describes a hydrogenation method for degrading polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) in supercritical carbon dioxide catalyzed by palladium nanoparticles stabilized in polydimethylsiloxane (Pd/PDMS). The process of synthesizing metal nanoparticles embedded in PDMS polymers involves the preparation of a homogenous mixture of metal salt, silicone elastomer, and a curing agent, followed by hydrogen reduction.

Abstract(#br)A novel and very simple microextraction approach for pre-concentration and direct solid phase spectrophotometric measurement has been developed for the determination of chromogenic analytes. The model analyte to assess this approach was the chromophore malachite green (MG). The analyte was extracted from water samples onto a small rotating disk made of Teflon containing a sorbent phase of polydimethylsiloxane (PDMS) on one of its surfaces. We refer to the extraction procedure as rotating disk sorptive extraction (RDSE).

Abstract(#br)The in vivo cellular microenvironment is regulated by a complex interplay of soluble factors and signaling molecules secreted by cells and it plays a critical role in the growth and development of normal and diseased tissues. In vitro systems that can recapitulate the microenvironment at the cellular level are needed to investigate the influence of autocrine signaling and extracellular matrix effects on tissue homeostasis, regeneration, disease development and progression.