PDMS

Abstract(#br)This paper describes rapid, simple, and cost-effective treatments for producing biocompatible and long-term hydrophilic polydimethylsiloxane (PDMS) surfaces identified in an experimental study investigating 39 treatments in all. The wetting of the surfaces was monitored during six months. Changes in surface morphology and chemical composition were also analyzed. Some of the treatments are presented here for the first time, while for earlier presented treatments the selection of investigated parameters was wider and the observation period for the surface wetting longer.

Abstract(#br)Very thin polydimethylsiloxane (PDMS)-layer with a mean thickness of 3–5\u003cce:hsp sp=\"0.25\"/\u003enm was formed on Cu particles by using thermal evaporation of PDMS at 200\u003cce:hsp sp=\"0.25\"/\u003e°C under nitrogen atmosphere. Using X-ray photoelectron spectroscopy and FT-IR, it was shown that the dimethylsiloxane framework was sustained after evaporation of PDMS and its deposition on Cu particles.

Abstract(#br)Adhesion tests were performed on single macroscopic pillars as model systems for artificial gecko surfaces. Polydimethylsiloxane macropillars with 400\u003cce:hsp sp=\"0.25\"/\u003eμm diameter and aspect ratios ranging from 1 to 5 were fabricated. The tip geometries were modified to achieve spherical, flat and mushroom shaped tips. Unlike spherical tips, flat tip pillars exhibited a strong angle dependency of the pull-off force. For mushroom shaped tips the pull-off force was tilt angle dependent only for low preload, where no complete tip contact was formed.

Abstract(#br)This study demonstrates the high performance of GaAs solar cells with dual-layer CdS quantum dots (QDs) carried by flexible polydimethylsiloxane (PDMS) film. Several parameters were enhanced, including the short circuit current, fill factor, and power conversion efficiency, which were measured under white light illumination similar to the solar spectrum. The flexible PDMS film was fabricated using the spin-coating technique, and was then used to embed dual-layer CdS QDs. Different concentrations of QDs were applied in this design to test the optimal combination.

Abstract(#br)The transport properties of gases in polydimethylsiloxane (PDMS)/zeolite A mixed matrix membranes (MMMs) were determined based on pure gas permeation experiments. MMMs were prepared by incorporating zeolite 4A nanoparticles into a PDMS matrix using a new procedure. The permeation rates of C 3 H 8 , CH 4 , CO 2 , and H 2 were evaluated through a dense homogeneous pure PDMS membrane and PDMS/4A MMMs to assess the viability of these membranes for natural gas sweetening and hydrogen purification. SEM investigations showed good adhesion of the polymer to the zeolite in MMMs.

Abstract(#br)The present study explores the fundamental science of estimating sorption of gases in membranes comprised of inorganic porous fillers within a polymer matrix with a novel semi-empirical correlation. The sorption properties of H 2 , C 3 H 8 , CO 2 and CH 4 were determined in polydimethylsiloxane (PDMS)/zeolite 4A mixed matrix membranes (MMMs) to assess the viability of these membranes for hydrogen purification and natural gas sweetening. Zeolite filling in MMMs results an increase in solubility over neat PDMS membrane.

Abstract(#br)Hematogenous metastasis involves a glycoprotein mediated adhesion cascade of tumor cells with E-selectin on the endothelial layer of the blood vessels. Cell–cell interactions play a major role in cancer metastasis and invasiveness. Intercellular communication between two cancer cells or between a cancer cell with a stromal cell in the microenvironment such as fibroblasts or inflammatory cells play an important role in metastatic invasion. Culturing tumor cells as 3D spheroids can recapitulate these physiologically relevant cell–cell interactions.

Abstract(#br)Gas permeability through synthesized polydimethylsiloxane (PDMS)/zeolite 4A mixed matrix membranes (MMMs) were investigated with the aid of artificial neural network (ANN) approach. Kinetic diameter and critical temperature of permeating components (e.g. H 2 , CH 4 , CO 2 and C 3 H 8 ), zeolite content and upstream pressure as input variables and gas permeability as output were inspected. Collected data of the experimental operation was used to ANN training and optimum numbers of hidden layers and neurons were obtained by trial-error method.

Abstract(#br)Polydimethylsiloxane (PDMS) based microdevices have bought revolutionary change in the chemical analysis. Suitable mechanical properties of PDMS make it amenable for soft lithography and certain optical properties like transparency in Near InfraRed (NIR) make it a yet unexplored option for use as a window material in Fourier Transform InfraRed (FTIR) Spectrometers. We investigate the utility of PDMS as a transmittance cell kit in FTIR Spectrometer replacing the CaF 2 windows.

Abstract(#br)In Organic Solvent Nanofiltration (OSN), the exact effect of pressure (0.1–5\u003cce:hsp sp=\"0.25\"/\u003eMPa range) on the membrane, mass transfer and membrane selectivity is still unclear despite the many investigations that have been reported in the last decade. The same questions continue to be raised: Does pressure contribute to both convective and diffusive flux? Does pressure induce polymer compaction?