Cryostructuration as a tool for preparing highly porous polymer materials

2011 ◽  
Vol 2 (5) ◽  
pp. 1059 ◽  
Author(s):  
Harald Kirsebom ◽  
Bo Mattiasson
Keyword(s):  
Porous Polymer ◽  
Polymer Materials ◽  
Highly Porous

scholarly journals Ethanol steam reforming over Co Ru nanoparticles supported on highly porous polymer-based carbon material

2019 ◽  
Vol 128 ◽  
pp. 105717 ◽  
Author(s):  
Mikhail N. Efimov ◽  
Elena Yu. Mironova ◽  
Andrey A. Vasilev ◽  
Dmitriy G. Muratov ◽  
Aleksey A. Averin ◽  
...  
Keyword(s):  
Steam Reforming ◽  
Carbon Material ◽  
Porous Polymer ◽  
Ethanol Steam Reforming ◽  
Ru Nanoparticles ◽  
Highly Porous ◽  
Ethanol Steam

Large Deformation Behavior of Porous Polymer Materials With 3D Random Pore Structure: Experimental Investigation and FEM Modeling

2019 ◽  
Author(s):  
Kanako Emori ◽  
Tatsuma Miura ◽  
Akio Yonezu
Keyword(s):  
Plastic Deformation ◽  
Pore Structure ◽  
Creep Deformation ◽  
Deformation Behavior ◽  
Superposition Principle ◽  
Critical Role ◽  
Test Sample ◽  
Porous Polymer ◽  
Polymer Materials ◽  
Polymeric Membrane

Abstract This study investigates the deformation behavior of porous polymer materials with 3D random pore structure. The test sample has sub-micron-sized pores with an open cellular structure, which plays a critical role for water purification. The base polymer is PVDF (polyvinylidene difluoride). First, the surface and cross section of the sample are observed using FESEM to investigate the microstructure (cell size and geometry of the cell ligament, etc). Next, uni-axial tensile loading is carried out for polymeric membrane and it is found that the membranes underwent elasto-plastic deformation. In order to establish a numerical model, finite element metod (FEM) is employed. Using a software of Surface Evolver, 3D random pore structure is created in the representative volume element (RVE). The established computational model can predict both elastic deformation and plastic deformation. Furthermore, viscoplastic deformation behavior (i.e. time-dependent deformation and creep deformation) is investigated, experimentally and numerically. In particular, creep compliance is measured, and we investigate the effect of applied loading on creep deformation behavior. Using the time–temperature–stress superposition principle (TTSSP), we obtain a new master curve, which covers higher stress level, and successfully establish an FEM model of creep deformation of the test sample. The present model enables the prediction of the macroscopic and microscopic deformation behavior of the porous materials, by taking into account of 3D random pore structure.

scholarly journals Preparation of Porous Biodegradable Polymer and Its Nanocomposites by Supercritical CO2Foaming for Tissue Engineering

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Xia Liao ◽  
Haichen Zhang ◽  
Ting He
Keyword(s):  
Carbon Dioxide ◽  
Tissue Engineering ◽  
Polymer Nanocomposites ◽  
Biodegradable Polymer ◽  
Processing Parameters ◽  
Porous Polymer ◽  
Polymer Materials ◽  
Biodegradable Materials ◽  
High Level ◽  
Foaming Technology

Using supercritical carbon dioxide (scCO2) as an alternative to conventional methods in the preparation of porous biodegradable polymer and polymer/nanocomposites for tissue engineering has attracted increasing interest in recent years due to the absence of using organic solvents and the ability to incorporate thermosensitive biologicals without loss of bioactivity. Additionally, scCO2can exert a high level of control over porosity and morphology of scaffolds by tuning the processing parameters. This paper describes the newly achievements on the preparation of porous polymer materials using scCO2foaming technology with focus on the porous biodegradable materials and its nanocomposites relevant to tissue engineering.

Wave Polymerization During Vapor Deposition of Porous Parylene-N Dielectric Films

1999 ◽  
Vol 565 ◽  
Author(s):  
James Erjavec ◽  
John Sikita ◽  
Stephen P. Beaudoin ◽  
Gregory B. Raupp
Keyword(s):  
Reaction Front ◽  
Wave Process ◽  
Liquid Nitrogen Temperature ◽  
Porous Polymer ◽  
Polymerization Process ◽  
Dielectric Films ◽  
Chamber Pressure ◽  
Porous Films ◽  
Deposition Rates ◽  
Highly Porous

AbstractParylene-N films vapor deposited near liquid nitrogen temperature (77 K) undergo a unique ‘wave’ polymerization process in which a rapidly moving reaction front is apparent as the film changes from translucent to optically opaque. This moving reaction front produces a highly porous polymer film. The porosity of these films is approximately 80%. By capturing the wave process on video we have quantified the moving ‘wave’ velocity, which averages 11 cm/s. Timeaveraged deposition rates of the resulting opaque, porous films are more than 8 μm/min. This rate is more than two orders of magnitude greater than the measured deposition rates of nonporous films that are deposited at higher temperatures, at otherwise fixed conditions of monomer delivery rate and deposition chamber pressure.

Organic Porous Polymer Materials: Design, Preparation, and Applications

2017 ◽  
pp. 71-150
Author(s):  
Liangxiao Tan ◽  
Kewei Wang ◽  
Qingyin Li ◽  
Yuwan Yang ◽  
Yunfei Liu ◽  
...  
Keyword(s):  
Materials Design ◽  
Porous Polymer ◽  
Polymer Materials

scholarly journals Analysis of Void Growth and Coalescence in Porous Polymer Materials. Coalescence in Polymer Materials

2013 ◽  
Vol 3 (3) ◽  
pp. 452-460
Author(s):  
S. A. Reffas ◽  
M. Elmeguenni ◽  
M. Benguediab
Keyword(s):  
Volumetric Strain ◽  
Polymeric Materials ◽  
Porous Polymer ◽  
Polymer Materials ◽  
Geometrical Shape ◽  
Engineering Applications ◽  
Initial Size ◽  
Advanced Stages ◽  
New Methodologies ◽  
Void Growth And Coalescence

The use of polymeric materials in engineering applications is growing more and more all over the world. This issue requests new methodologies of analysis in order to assess the material’s capability to withstand complex loads. The use of polyacetal in engineering applications has increased rapidly in the last decade. In order to evaluate the behavior, the damage and coalescence of this type of polymer, a numerical method based on damage which occurs following several stages (nucleation of cavities, their growth and coalescence in more advanced stages of deformation) is proposed in this work. A particular attention is given on the stress-strain and the volumetric strain evolution under different triaxiality and for three initial void shapes. Its application to polyacetal allows approving this approach for technical polymers. Finally, this method allow us to compare the obtained results of basic calculations at different triaxiality and to discuss their possible influence on the initial size and the geometrical shape of the porosity on the material failure.

scholarly journals Drying kinetics and acoustic properties of soft porous polymer materials

2020 ◽  
Author(s):  
R. Kumar ◽  
Y. Jin ◽  
S. Marre ◽  
O. Poncelet ◽  
T. Brunet ◽  
...  
Keyword(s):  
Drying Kinetics ◽  
Porous Polymer ◽  
Polymer Materials ◽  
Acoustic Properties

scholarly journals Process Development of CO2-Assisted Polymer Compression for High Productivity: Improving Equipment and the Challenge of Numbering-Up

Technologies ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 39 ◽  
Author(s):  
Takafumi Aizawa
Keyword(s):  
Pressure Vessel ◽  
Process Development ◽  
Flow Line ◽  
Porous Polymer ◽  
Sample Introduction ◽  
Polymer Materials ◽  
High Productivity ◽  
High Pressure Co2 ◽  
Increase Productivity ◽  
Co2 Flow

The CO2-assisted polymer compression method is used herein to prepare porous polymer materials by bonding laminated polymer fiber sheets using a piston in the presence of CO2. In this work, the CO2 flow line connections were moved from the pressure vessel to the piston to increase productivity, which makes the pressure vessel free-moving and the processing time of sample introduction and removal seemingly zero. In addition, a numbering-up method suitable for CO2-assisted polymer compression is proposed and verified based on the variability of the products. The variability of the product was evaluated using porosity, which is one of the most important properties of a porous material. It is found that the CO2 exhaust process, specific to this method, that uses high-pressure CO2, causes product variation, which can be successfully suppressed by optimizing the CO2 exhaust process.

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