scholarly journals Evolution of the Surface Structure and Functional Properties of the Electroconducting Polymer Coatings onto Porous Films

Coatings ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 51
Author(s):  
Galina Kazimirovna Elyashevich ◽  
Dmitry Igorevich Gerasimov ◽  
Ivan Sergeevich Kuryndin ◽  
Viktor Konstantinovich Lavrentyev ◽  
Elena Yurievna Rosova ◽  
...  
Keyword(s):  
Polyvinylidene Fluoride ◽  
Oxidative Polymerization ◽  
Film Surface ◽  
Thermal Stabilization ◽  
Polymer Melt ◽  
Polymer Coatings ◽  
Porous Films ◽  
Porous Support ◽  
Conducting Coating ◽  
Porous Supports

Composite systems containing electroconducting polymer coatings (polyaniline and polypyrrole) applied to porous films of semicrystalline polymers (polyethylene, polypropylene, and polyvinylidene fluoride) have been prepared. Porous supports were obtained in the process based on polymer melt extrusion with subsequent annealing, uniaxial extensions, and thermal stabilization. Conducting coatings were formed by the oxidative polymerization of the monomers directly onto the porous supports. The structure (overall porosity, permeability, pore sizes, factor of orientation) and morphology (specific surface and character of the film surface) of the supports were characterized by sorptometry, filtration porosimetry, atomic force microscopy (AFM), and X-ray scattering techniques. It was observed that the porous supports have a strongly developed relief surface which is formed in the pore formation process. It was proven by scanning electron microscopy (SEM) that the porous supports have an oriented structure, and the surface of the composites is defined by the morphology inherent in the conducting component. It was shown that these composites (porous support/conducting coating) demonstrate electric conductivity both along the surface and between surfaces. It was demonstrated that the deposition of conducting coatings leads to an increase in the water wettability of the composites compared with pronounced hydrophobic supports. The composites are characterized by good adhesion between components due to a relief film surface as well as high mechanical strength and elasticity provided by the oriented character of the supports.

Characterization of the Surface Area and Porosity of Sol-Gel Films Using Saw Devices

1988 ◽  
Vol 121 ◽  
Author(s):  
Gregory C. Frye ◽  
Antonio J. Ricco ◽  
Stephen J. Martin ◽  
C. Jeffrey Brinker
Keyword(s):  
Pore Size ◽  
Surface Area ◽  
Adsorption Isotherms ◽  
Sol Gel ◽  
Film Surface ◽  
Nitrogen Adsorption ◽  
Porous Films ◽  
Pore Size Distributions ◽  
Test Film ◽  
Sol Gel Films

ABSTRACTA novel technique for accurately obtaining nitrogen adsorption isotherms on thin porous films has been developed. These isotherms are useful for characterizing the surface area and pore size distribution of porous samples. The sensitivity to adsorbed nitrogen is increased by several orders of magnitude over conventional techniques by forming the test film on the substrate of a surface acoustic wave (SAW) device. This device functions as a microbalance able to detect less than 100 pg/cm2 of film. Surface areas and pore size distributions calculated from adsorption isotherms obtained with this technique on silicate sol-gel films are compared to those for bulk samples prepared from similar sol-gel solutions.

Preparation and Self-Assembling of PLA-b-PNIPAM-b-PS Triblock Copolymer Thin Films

2021 ◽  
Vol 21 (4) ◽  
pp. 2174-2184
Author(s):  
Diansen Zhang ◽  
Yuzheng Xia ◽  
Hongliang Gong ◽  
Dong Zhang ◽  
Xiaonong Chen ◽  
...  
Keyword(s):  
Microphase Separation ◽  
Film Surface ◽  
Chemical Compositions ◽  
Stimuli Responsive ◽  
Porous Films ◽  
Force Microscopy ◽  
Self Assembling ◽  
Atomic Force ◽  
Reversible Addition ◽  
Self Assembled

Polylactide-b-poly(N-isopropylacrylamide)-b-polystyrene (PLA-b-PNIPAM-b-PS) triblock copolymers (tri-BCPs) with various chemical compositions (block ratio) were prepared from the combination of ring-opening polymerization and reversible addition-fragmentation chain transfer polymerization. Subsequently, the self-assembling behaviors of these tri-BCP films obtained from spin-coating were investigated by annealing them under different solvent atmosphere. We found that these films could self-assemble into various morphologies due to the microphase separation of incompatible copolymer blocks. Atomic force microscopy confirmed the perpendicular cylindrical morphology self-assembled from PLA4.5k-b-PNIPAM5.2k-b-PS22.4k tri-BCP film under mixed solvent atmosphere of toluene/acetone (7:3, v/v). Self-assembled PLA cylinders are evenly distributed among the PS matrix and perpendicular to the film surface, with PNIPAM component taking place at the PLA/PS interphase. Furthermore, by etching the degradable PLA component, porous PS film decorated with PNIPAM “brushes” hoisting channels were generated. This work provides a facile method and detailed protocol for fabricating stimuli-responsive porous films which are promising for thermoresponsive “smart” separation technologies.

Porous membranes based on poly(ether imide)-graft-poly(vinyl acetate) as a scaffold for cell growth

2017 ◽  
Vol 33 (2) ◽  
pp. 178-194 ◽  
Author(s):  
Bin Liu ◽  
Jiangying Kuang ◽  
Leishan Shao ◽  
Xinyuan Che ◽  
Fei Wang ◽  
...  
Keyword(s):  
Cell Growth ◽  
Vinyl Acetate ◽  
Photoelectron Spectroscopy ◽  
Weight Ratio ◽  
Film Surface ◽  
Porous Film ◽  
Surface Topology ◽  
Proton Nuclear Magnetic Resonance ◽  
Porous Films ◽  
Breath Figure

A series of poly(ether imide)-graft-poly(vinyl acetate) copolymers with different molecular weights were synthesized successfully and characterized using Fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy, proton nuclear magnetic resonance, gel permeation chromatography, differential scanning calorimeter, thermogravimetric analysis, and X-ray photoelectron spectroscopy analyses. These copolymers were used to fabricate honeycomb-structured porous films using the breath figure templating technique. The surface topology and composition of the highly ordered pattern film were further characterized using a scanning electron microscopy. The results indicated that the poly(ether imide)-graft-poly(vinyl acetate) graft molecular weight ratio influenced the breath figure film surface topology. A model was proposed to elucidate the stabilization process of the poly(ether imide)-graft-poly(vinyl acetate)-aggregated architecture on the water droplet–based templates. In addition, cell viability has been investigated via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide test, and the cell morphology on the honeycomb-structured poly(ether imide)-graft-poly(vinyl acetate) porous film has been evaluated using a fluorescence microscope. This porous film is shown to be suitable as a matrix for cell growth.

Preparation of Continuous Mesoporous Films on Porous and Dense Substrates

1996 ◽  
Vol 431 ◽  
Author(s):  
J. Liu ◽  
J. R. Bontha ◽  
A. Y. Kim ◽  
S. Baskaran
Keyword(s):  
Surfactant Solution ◽  
Silicate Solution ◽  
Diffusion Cell ◽  
Transparent Film ◽  
Mesoporous Films ◽  
Porous Support ◽  
Surfactant Solutions ◽  
Mesoporous Film ◽  
Cell Reactor ◽  
Porous Supports

AbstractHigh quality, continuous mesoporous films are prepared on both porous and dense substrates. An interfacial reaction mechanism is used to grow mesoporous films within the pores of porous supports using a diffusion cell reactor. The porous support was placed between two compartments containing a silicate solution in one compartment and a surfactant solution in the other. The silicate and surfactant solutions diffused into the support to form a mesoporous film at the liquid-liquid interface. This method produces a transparent film free from large defects. Spincoating technique is also used to prepare mesoporous films on dense substrates. These films have uniform thickness and show well-defined interference depending on the film thickness.

scholarly journals Influences of pH and EDTA Additive on the Structure of Ni Films Electrodeposited by Using Bubble Templates as Electrocatalysts for Hydrogen Evolution Reaction

Membranes ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 165
Author(s):  
Xiangtao Yu ◽  
Jun Yang ◽  
Xiangyu Ren ◽  
Zhuyin Sui
Keyword(s):  
Coordination Number ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Ph Value ◽  
Film Surface ◽  
Catalytic Performance ◽  
Side Reactions ◽  
Surface Acting ◽  
Porous Films ◽  
Solution Ph

The structure of Ni films is essential to their electrocatalytic performance for hydrogen evolution reaction (HER). The pH value and EDTA (ethylene diamine tetraacetic acid) additive are important factors for the structure control of electrodeposited metal films due to their adjustment of metal electrocrystallization and hydrogen evolution side reactions. The structures of Ni films from 3D (three-dimensional) porous to compact and flat structure are electrodeposited by adjusting solution pH values or adding EDTA. It is found that when pH value increases from 7.7 to 8.1, 3D porous films change to compact films with many protrusions. Further increasing the pH value or adding 0.1 M EDTA causes compact and flat films without protrusions to appear. When pH ≤ 7.7, hydrogen bubbles with large break-off diameter are easily adsorbed on film surface acting as porous structure templates, and the electroactive ion species, Ni2+ and Ni(NH3)n2+ complexes with low coordination number (n ≤ 3), possess high reduction overpotential, which is beneficial to forming protrusions and smaller particles. So, porous Ni films are electrodeposited. In solutions with pH ≥ 8.1 or 0.1 M EDTA, Ni(NH3)n2+ complexes with high coordination number (6 ≥ n ≥ 3) and hexadentate chelate are formed. Due to the improved wettability, bubbles with a small break-off diameter rapidly detach the film surface resulting in strong stirring. The reduction overpotential is reduced, leading to the formation of larger particles. Therefore, the solution leveling ability increases, and it is difficult to form protrusions, thus it forms a compact and flat film. The 3D porous film exhibits excellent catalytic performance for HER due to the large catalytic activity area.

scholarly journals Production Technology and Damping Properties of Aerated Polymer Coatings

2021 ◽  
Vol 20 (5) ◽  
pp. 375-382
Author(s):  
V. K. Sheleg ◽  
Ma Min ◽  
M. A. Belotserkovsky
Keyword(s):  
Polymer Melt ◽  
Polymer Coatings ◽  
Flame Spraying ◽  
Damping Properties ◽  
Melt Flow Rate ◽  
Concurrent Flow ◽  
Liquid Polymers ◽  
High Pressure Polyethylene ◽  
Induction Type ◽  
Kinematic Diagram

The process of obtaining aerated (filled with air bubbles) polymer coatings has been developed and investigated by the method of flame spraying with an assessment of their ability to damp vibrations. A technology for the controlled formation of aerated polymer coatings has been developed while using the capabilities of the ОИМ (OIM) 050 polymer thermal atomizer design which consists in providing a concurrent air flow between the flame torch and the jet of powder material. The experiments have been carried out with such thermoplastic polymers as polyethylene terephthalate, high pressure polyethylene, ultra high molecular weight polyethylene, polyamide. It has been found that the aeration coefficient grows almost in direct proportion with an increase in the amount of air in the concurrent flow for all investigated polymer coatings. It is noted that the aeration process is influenced by the rheological properties of liquid polymers, or rather, the value of the polymer melt flow rate. The limiting values of air in the concurrent flow have been determined, which make it possible not to reduce the adhesion of polymer coatings to steel substrates by less than 6 MPa and not to decrease their hardness by more than 25–30 %. Studies of the damping properties of samples with polymer coatings have been carried out on a stand, the kinematic diagram of which is based on loading the free end of a cantilever sample, abrupt removal of the load and registration of free damped oscillations by an induction-type contactless sensor connected to a computer. It is shown that the use of aeration when forming noise-absorbing coatings on steel samples can increase their logarithmic damping decrement by 18–26 %.

Through Permeability of Polyvinylidene Fluoride Piezoactive Porous Films

2018 ◽  
Vol 60 (6) ◽  
pp. 734-741 ◽  
Author(s):  
G. K. Elyashevich ◽  
I. S. Kuryndin ◽  
V. K. Lavrentyev ◽  
I. Yu. Dmitriev
Keyword(s):  
Polyvinylidene Fluoride ◽  
Porous Films

scholarly journals Induced Hydrophilicity and In Vitro Preliminary Osteoblast Response of Polyvinylidene Fluoride (PVDF) Coatings Obtained via MAPLE Deposition and Subsequent Thermal Treatment

Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 582
Author(s):  
Luminita Nicoleta Dumitrescu ◽  
Patricia Neacsu ◽  
Madalina G. Necula ◽  
Anca Bonciu ◽  
Valentina Marascu ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermal Treatment ◽  
Polyvinylidene Fluoride ◽  
Cellular Response ◽  
Control Sample ◽  
Chemical Properties ◽  
Polymer Coatings ◽  
Deposition Parameters

Recent advancements in biomedicine have focused on designing novel and stable interfaces that can drive a specific cellular response toward the requirements of medical devices or implants. Among these, in recent years, electroactive polymers (i.e., polyvinylidene fluoride or PVDF) have caught the attention within the biomedical applications sector, due to their insolubility, stability in biological media, in vitro and in vivo non-toxicity, or even piezoelectric properties. However, the main disadvantage of PVDF-based bio-interfaces is related to the absence of the functional groups on the fluoropolymer and their hydrophobic character leading to a deficiency of cell adhesion and proliferation. This work was aimed at obtaining hydrophilic functional PVDF polymer coatings by using, for the first time, the one-step, matrix-assisted pulsed evaporation (MAPLE) method, testing the need of a post-deposition thermal treatment and analyzing their preliminary capacity to support MC3T3-E1 pre-osteoblast cell survival. As osteoblast cells are known to prefer rough surfaces, MAPLE deposition parameters were studied for obtaining coatings with roughness of tens to hundreds of nm, while maintaining the chemical properties similar to those of the pristine material. The in vitro studies indicated that all surfaces supported the survival of viable osteoblasts with active metabolisms, similar to the “control” sample, with no major differences regarding the thermally treated materials; this eliminates the need to use a secondary step for obtaining hydrophilic PVDF coatings. The physical-chemical characteristics of the thin films, along with the in vitro analyses, suggest that MAPLE is an adequate technique for fabricating PVDF thin films for further bio-applications.

scholarly journals Структура и фазовый состав пленок, полученных методом лазерного спекания из поливинилиденфторида различных марок

2021 ◽  
Vol 47 (23) ◽  
pp. 15
Author(s):  
Е.Ю. Тарасова ◽  
И.И. Журавлева ◽  
И.А. Бакулин ◽  
С.И. Кузнецов ◽  
А.С. Панин
Keyword(s):  
Laser Treatment ◽  
Polyvinylidene Fluoride ◽  
Oxidative Degradation ◽  
Polymer Melt ◽  
Melt Flow Index ◽  
Flow Index ◽  
Laser Exposure ◽  
Β Phase ◽  
Treatment Conditions ◽  
Porosity Coefficient

The processes of laser synthesis of films with a thickness of 80-230 µm from polyvinylidene fluoride of various grades are studied. It is established that the range of synthesis modes does not depend on the grades of PVDF. The content of the piezo active β-phase decreases after laser treatment, but the complete transformation of β→α does not occur. The process of thermos-oxidative degradation after laser treatment is not observed. Under the same treatment conditions, the higher the open porosity coefficient, the lower the polymer melt flow index (MFI). Depending on the MFI of the initial polymer, the selection of laser exposure modes can control the porosity of the films in the range of 26-68 %.

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