Browse
Submit Data
Databases
API
Help

Dataset Information

10 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Preparation of Bisphenol-A and Polydimethylsiloxane (PDMS) Block Copolycarbonates by Melt Polycondensation: Effects of PDMS Chain Length on Conversion and Miscibility.

ABSTRACT: This study aimed to improve polydimethylsiloxane (PDMS) conversion in the preparation of polycarbonate (PC)-polydimethylsiloxane (PDMS) copolymer through melt polycondensation. We examined the transesterification process of PDMS with diphenyl carbonate (DPC) and its copolymerization products with bisphenol-A (BPA) for different chain lengths of PDMS. The key factors affecting PDMS conversion were investigated. Results showed that long-chain PDMS required a higher critical transesterification level (38.6%) to improve miscibility with DPC. During polycondensation, side reactions were more prone to occur when the equilibrium transesterification level of long-chain PDMS was lower. PDMS conversion was also lower when more short-chain PDMS was fed. Increasing the chain length of PDMS also reduced PDMS conversion. Notably, increasing the amount of KOH can significantly improve PDMS conversion throughout the polycondensation stage by increasing the equilibrium transesterification level of long-chain PDMS, thereby inhibiting the occurrence of side reactions.

SUBMITTER: Zhou Z

PROVIDER: S-EPMC8401443 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Photolithographic surface micromachining of polydimethylsiloxane (PDMS).

Project description:A major technical hurdle in microfluidics is the difficulty in achieving high fidelity lithographic patterning on polydimethylsiloxane (PDMS). Here, we report a simple yet highly precise and repeatable PDMS surface micromachining method using direct photolithography followed by reactive ion etching (RIE). Our method to achieve surface patterning of PDMS applied an O(2) plasma treatment to PDMS to activate its surface to overcome the challenge of poor photoresist adhesion on PDMS for photolithography. Our photolithographic PDMS surface micromachining technique is compatible with conventional soft lithography techniques and other silicon-based surface and bulk micromachining methods. To illustrate the general application of our method, we demonstrated fabrication of large microfiltration membranes and free-standing beam structures in PDMS.

| S-EPMC4120064 | biostudies-literature

Disposable Polydimethylsiloxane (PDMS)-Coated Fused Silica Optical Fibers for Sampling Pheromones of Moths.

Project description:In the past decades, the sex pheromone composition in female moths has been analyzed by different methods, ranging from volatile collections to gland extractions, which all have some disadvantage: volatile collections can generally only be conducted on (small) groups of females to detect the minor pheromone compounds, whereas gland extractions are destructive. Direct-contact SPME overcomes some of these disadvantages, but is expensive, the SPME fiber coating can be damaged due to repeated usage, and samples need to be analyzed relatively quickly after sampling. In this study, we assessed the suitability of cheap and disposable fused silica optical fibers coated with 100 ?m polydimethylsiloxane (PDMS) by sampling the pheromone of two noctuid moths, Heliothis virescens and Heliothis subflexa. By rubbing the disposable PDMS fibers over the pheromone glands of females that had called for at least 15 minutes and subsequently extracting the PDMS fibers in hexane, we collected all known pheromone compounds, and we found a strong positive correlation for most pheromone compounds between the disposable PDMS fiber rubs and the corresponding gland extracts of the same females. When comparing this method to volatile collections and the corresponding gland extracts, we generally found comparable percentages between the three techniques, with some differences that likely stem from the chemical properties of the individual pheromone compounds. Hexane extraction of cheap, disposable, PDMS coated fused silica optical fibers allows for sampling large quantities of individual females in a short time, eliminates the need for immediate sample analysis, and enables to use the same sample for multiple chemical analyses.

| S-EPMC4988701 | biostudies-literature

Cascade aza-Michael Addition-Cyclizations; Toward Renewable and Multifunctional Carboxylic Acids for Melt-Polycondensation.

Project description:Although the aza-Michael addition reaction on various unsaturated (di-)carboxylic acids and esters of, for example, itaconic acid, is well-known, the consecutive cyclization reaction has not received much attention in literature. The products of this aza-Michael cascade reaction, being mono- or di-carboxylic acid or ester functionalized N-alkyl-pyrrolidone structures, prove interesting for melt-polycondensation reactions as they exhibit excellent stability at elevated temperatures. In other words, this reaction is a toolbox for the generation of renewable monomers and, in turn, polymers with tunable physiological properties. Therefore, this work provides an overview of the state-of-the-art of the cascade aza-Michael addition-cyclization reactions on biobased unsaturated acids and esters, and their use in polymerization reactions. Furthermore, we extend this overview with the cascade aza-Michael addition-cyclization reaction of trans-trimethyl aconitate with di-amines to form a tetra-functional N-alkyl-bis-(pyrrolidone dimethylcarboxylate), which exhibits excellent thermal stability and could effectively be used as monomer in polycondensation reactions. Importantly, the aza-Michael addition reaction between primary amines and trans-trimethyl aconitate can be considered a click-reaction; it proceeds quantitatively within minutes under ambient conditions and follows the principles of green chemistry.

| S-EPMC6868100 | biostudies-literature

Comprehensive constitutive modeling and analysis of multi-elastic polydimethylsiloxane (PDMS) for wearable device simulations.

Project description:Within the field of wearable devices, polydimethylsiloxane (PDMS) has long been one of the most prominent materials utilized. It is therefore unsurprising that demands for its usage has now extended beyond experimental works into computational simulations, particularly those involving finite element method (FEM). To replicate the mechanical properties of PDMS in FEM, an accurate constitutive model is required, preferably one that encompasses wide ranges of PDMS elasticity. In this study, we determine Mooney-Rivlin 5 parameters as the best hyperelastic model fitted against PDMS experimental data, and proceed to construct a parameter correlation plot combining PDMS of different elasticities together. Experimental validation using PDMS samples fabricated via 3D-printed molds is then performed using parameters extracted from this plot, showing good agreement between simulation and experimental result. In addition, to reflect model applicability, simulations related to basic mechanical deformations involved in flexible devices (compression, stretching, bending and twisting) are performed and analyzed. Further analysis is also performed to investigate the effect of combining different experimental datasets as input into the model. We expect our work to be potentially helpful to be applied as both framework and database for wearable device engineers and researchers who are experimenting with varying PDMS concentrations and modulus.

| S-EPMC10611765 | biostudies-literature

Fabrication of Bendable Circuits on a Polydimethylsiloxane (PDMS) Surface by Inkjet Printing Semi-Wrapped Structures.

Project description:In this work, an effective method was developed to fabricate bendable circuits on a polydimethylsiloxane (PDMS) surface by inkjet printing semi-wrapped structures. It is demonstrated that the precured PDMS liquid film could influence the depositing morphology of coalesced silver precursor inkjet droplets. Accordingly, continuous and uniform lines with a semi-wrapped structure were fabricated on the PDMS surface. When the printed silver precursor was reduced to Ag nanoparticles, the fabricated conductive film exhibited good transparency and high bendability. This work presented a facile way to fabricate flexible patterns on a PDMS surface without any complicated modification or special equipment. Meanwhile, an in situ hydrazine reduction of Ag has been reported using the vapor phase method in the fabricating process.

| S-EPMC5502917 | biostudies-literature

Low cost fabrication and assembly process for re-usable 3D polydimethylsiloxane (PDMS) microfluidic networks.

Project description:A method to easily manufacture and assemble a polydimethylsiloxane (PDMS) based microfluidic device is described. The method uses low cost materials and re-usable laser cut polymethyl methacrylate (PMMA) parts. In addition, the thickness of PDMS layers can be controlled and both PDMS layer surfaces are flat, which allows for multi-layer PDMS structures to be assembled. The use of mechanical clamping to seal the structure allows for easy cleaning and re-use of the manufactured part as it can be taken apart at any time. In this way, selected layers can be re-used or replaced. The process described can be easily adopted and utilised without the need for any costly clean room facilities or equipment such as oxygen bonders, making it ideal for laboratories, universities, and classrooms exploring microfluidics applications.

| S-EPMC3364837 | biostudies-other

Surface stiffness, hydration, polydimethylsiloxane (PDMS), hyaluronic acid, biofilm and bacterial mobility, protein patterns.

Project description:By a global proteomic approach and phenotypic assays, we investigated the impact of surface stiffness on E. coli biofilm formation capacity. A global proteomic approach was used in order to identify the most abundant proteins for the comparison between E. coli adhesion in PDMS 9 kPa and 574kPa, (polydimethylsiloxane,), and between HA 44Pa and 2kPa (hyaluronic acid gels).

2023-03-11 | PXD035233 | Pride

Bismuth Quantum Dot (Bi QD)/Polydimethylsiloxane (PDMS) Nanocomposites with Self-Cleaning and Antibacterial Activity for Dental Applications.

Project description:In the oral microenvironment, bacteria colonies are easily aggregated on the tooth-restoration surface, in the manner of a biofilm, which usually consists of heterogeneous structures containing clusters of a variety of bacteria embedded in an extracellular matrix, leading to serious recurrent caries. In this contribution, zero-dimensional (0D) bismuth (Bi) quantum dots (QDs) synthesized by a facile solvothermal method were directly employed to fabricate a Bi QD/polydimethylsiloxane (PDMS)-modified tooth by simple curing treatment. The result demonstrates that the as-fabricated Bi QD/PDMS-modified tooth at 37 °C for 120 min not only showed significantly improved hydrophobic performance with a water contact angle of 103° and 115° on the tooth root and tooth crown, respectively, compared to that (~20° on the tooth root, and ~5° on the tooth crown) of the pristine tooth, but also exhibited excellent antibacterial activity against S. mutans, superior biocompatibility, and biosafety. In addition, due to the highly photothermal effect of Bi QDs, the antibacterial activity of the as-fabricated Bi QD/PDMS-modified tooth could be further enhanced under illumination, even at a very low power density (12 mW cm-2). Due to the facile fabrication, excellent hydrophobicity, superior antibacterial activity, and biocompatibility and biosafety of the Bi QD/PDMS-modified tooth, it is envisioned that the Bi QD/PDMS-modified tooth with a fascinating self-cleaning and antibacterial performance can pave the way to new designs of versatile multifunctional nanocomposites to prevent secondary caries in the application of dental restoration.

| S-EPMC9656007 | biostudies-literature

Hot melt extruded amorphous solid dispersion of posaconazole with improved bioavailability: investigating drug-polymer miscibility with advanced characterisation.

Project description:Invasive antifungal infections are reasons for morbidity and mortality in immunogenic patients worldwide. Posaconazole is a most promising antifungal agent against all types of invasive infections with high % of cure rate. The marketed suspension formulation has low bioavailability and is needed to be taken with food. In this paper, PCZ hot melt extruded amorphous solid dispersion (SD) with immediate release and improved bioavailability was prepared using Soluplus (Sol) as primary carrier for solubilization. Surfactants such as PEG 400, Lutrol F27, Lutrol F68, and TPGS are also used in combination with Soluplus to improve the physicochemical performance of the formulation when it comes in contact with GI (gastrointestinal) fluid. Drug-polymer miscibility of SD was investigated using advanced techniques. In the in vivo study, the AUC(0-72) and C(max) of PCZ/Soluplus were 11.5 and 11.74 time higher than those of pure PCZ. The formulation of the extrudate SD had an AUC(0-72) and C(max) higher than those with the commercial capsule (Noxafil). Molecular dynamic (MD) simulation studies were carried out using in silico molecular modelling to understand the drug-polymer intermolecular behaviour. The results of this research ensure enhanced dissolution and bioavailability of the solid dispersion of PCZ prepared by HME compared with the PCZ suspension.

| S-EPMC4131112 | biostudies-literature

Preparation and Performance of AgNWs/PDMS Film-Based Flexible Strain Sensor.

Project description:Flexible strain sensors are widely used in the fields of personal electronic equipment and health monitoring to promote the rapid development of modern social science and technology. In this paper, silver nanowires (AgNWs) prepared via the polyol reduction method were used to construct a flexible strain sensor. The AgNWs/PDMS film was obtained by transfer printing using AgNWs as a conductive layer and polydimethylsiloxane (PDMS) as a flexible substrate. The morphology of AgNWs was characterized by SEM and TEM. The aspect ratio of the AgNWs was more than 700. The strain sensitivity factor of the sensor was 2.8757, with a good linear relationship between the resistance and the strain. Moreover, the strain sensor showed good response results in human activity monitoring and the LED lamp response test, which provides a new idea for the construction of flexible wearable devices.

| S-EPMC9862830 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data