scholarly journals Preparation and Characterization of a Novel Poly(vinylidene fluoride-co-hexafluoropropylene)/Poly(ethersulfone) Blend Membrane Fabricated Using an Innovative Method of Mixing Electrospinning and Phase Inversion

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 790
Author(s):  
Norhan Nady ◽  
Noha Salem ◽  
Sherif. H. Kandil
Keyword(s):  
Contact Angle ◽  
Water Vapor ◽  
Phase Inversion ◽  
Vinylidene Fluoride ◽  
Water Vapor Permeability ◽  
Vapor Permeability ◽  
Water Contact ◽  
Static Water Contact Angle ◽  
Poly Vinylidene Fluoride ◽  
Static Water

In this work, a novel polymeric membrane was innovated in terms of composition and preparation techniques. A blend of poly(vinylidene fluoride-co-hexafluoropropylene) (PcH) and poly(ethersulfone) (PES) (18 wt.% total polymer concentration) was prepared using a N-methylpyrrolidone (NMP) and N, N-Dimethylformamide (DMF) solvents mixture, while Lithium chloride (0.05–0.5 wt.%) was used as an additive. The electrospinning and phase inversion techniques were used together to obtain a novel membrane structure. The prepared membranes were characterized using scanning electron microscope imaging, energy dispersive X-Ray, differential scanning calorimeter, thermogravimetric analysis, and Fourier transfer infrared spectroscopy-attenuated total reflectance analyses. Moreover, the static water contact angle, membrane thickness, porosity, surface roughness as well as water vapor permeability were determined. ImageJ software was used to estimate the average fiber diameter. Additionally, the effect of the change of PcH concentration and coagulation bath temperature on the properties of the fabricated membrane was studied. The novel developed membrane has shown a good efficiency in terms of properties and features, as a membrane suitable for membrane distillation (MD); a high porosity (84.4% ± 0.6), hydrophobic surface (136.39° ± 3.1 static water contact angle), and a water vapor permeability of around 4.37 × 10−5 g·m/m2·day·Pa were obtained. The prepared membrane can be compared to the MD membranes commercially available in terms of properties and economic value.

scholarly journals Synthesis of Silphenylene-Containing Siloxane Resins Exhibiting Strong Hydrophobicity and High Water Vapor Barriers

Coatings ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 481
Author(s):  
Chen ◽  
Yi ◽  
Wu ◽  
Tan ◽  
Xu ◽  
...  
Keyword(s):  
Contact Angle ◽  
Water Vapor ◽  
Water Contact Angle ◽  
Water Vapor Permeability ◽  
Barrier Properties ◽  
High Water ◽  
Vapor Permeability ◽  
One Pot ◽  
Water Contact ◽  
Thermal Stabilities

The novel phenylenedisilane, 1,4-bis(dimethoxyphenylsilyl)benzene (BDMPD), was successfully synthesized via the reaction between trimethoxyphenylsilane (TMPS) and a Grignard reagent originating from 1,4-dibromobenzene. In comparison to common Grignard reactions, this process was a facile one-pot method. 1H NMR spectroscopy, FT-IR measurements, and elemental analysis confirmed the predicted structure of BDMPD. In addition, vinyl-terminated polysiloxanes containing silphenylene units (VPSSP), which were hydrolytically copolymerized from BDMPD, TMPS, and divinyltetramethyldisiloxane, exhibited excellent thermal stabilities (T10%: 502 °C, Rw%: 76.86 beyond 700 °C) and suitable refractive indices (1.542). Furthermore, water contact angle and water vapor permeability tests confirmed that the fully cured siloxane resins containing VPSSP-based silphenylene units exhibited strong hydrophobicity (water contact angle: 119°) and superior water vapor barrier properties, thereby indicating their potential to serve as strong waterproof coatings for moisture-proof applications or as adhesives for use in immersed equipment.

scholarly journals Upcycling of Vine Shoots: Production of Fillers for PHBV-Based Biocomposite Applications

2020 ◽  
Author(s):  
Grégoire David ◽  
Laurent Heux ◽  
Stéphanie Pradeau ◽  
Nathalie Gontard ◽  
Hélène Angellier-Coussy
Keyword(s):  
Water Vapor ◽  
Gas Phase ◽  
Mechanical Performance ◽  
Low Cost ◽  
Water Vapor Permeability ◽  
Contact Angles ◽  
Vapor Permeability ◽  
Water Contact ◽  
Median Diameter ◽  
Cost Of Materials

Abstract This paper aims at investigating the potential of vine shoots (ViSh) upcycling as fillers in novel poly(3-hydroxybutyrate-3-hydroxyvalerate) (PHBV) based biocomposites. ViSh particles of around 50 µm (apparent median diameter) were obtained combining dry grinding processes, and mixed with PHBV using melt extrusion. Thermal stability and elongation at break of biocomposites were reduced with increasing contents of ViSh particles (10, 20 and 30 wt%), while Young’s modulus and water vapor permeability were increased. It was shown that a surface gas-phase esterification allowed to significantly increase the hydrophobicity of ViSh particles (increase of water contact angles from 59° to 114°), leading to a reduction of 27% in the water vapor permeability of the biocomposite filled with 30 wt% of ViSh. The overall mechanical performance was not impacted by gas-phase esterification, demonstrating that the interfacial adhesion between the virgin ViSh particles and the PHBV matrix was already good and that such filler surface treatment was not required in that case. It was concluded that ViSh particles can be interestingly used as low cost fillers in PHBV-based biocomposites to decrease the overall cost of materials.

Fast and simple fabrication of SiO2/poly(vinylidene fluoride) coated cotton fabrics with asymmetric wettability via a facile spray-coating route

2018 ◽  
Vol 89 (6) ◽  
pp. 1013-1026 ◽  
Author(s):  
Rongrong Yu ◽  
Mingwei Tian ◽  
Lijun Qu ◽  
Shifeng Zhu ◽  
Jianhua Ran ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Contact Angle ◽  
Water Contact Angle ◽  
Vinylidene Fluoride ◽  
Spray Coating ◽  
Cotton Fabrics ◽  
Water Repellent ◽  
Water Contact ◽  
Repellent Property ◽  
Poly Vinylidene Fluoride

Cotton fabrics with hydrophilic-to-hydrophobic asymmetric surfaces are attractive as potential utilizable structures for functional garments. The spray-coating route could be deemed as a fast and simple way to achieve asymmetric surfaces. In this paper, SiO2 nanoparticles with size ∼ 205 nm were synthesized via the modified sol-gel method, and then modified with poly(vinylidene fluoride) (PVDF) to form a hydrophobic surface. The SiO2 nanoparticles modified with PVDF were uniformly deposited on the outer surface of cotton fabric aided with the robust air flow force from the sprayer. The morphology and chemical structures were characterized by scanning electron microscopy, mapping, atomic force microscopy, X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy. The results indicated that SiO2 nanoparticles were evenly deposited on the surface of cotton fibers and stable interfacial interaction occurred between SiO2 and PVDF molecular chains. The existence of SiO2 could increase the roughness of the fabric surface, which could enhance the water-repellent property of the coated fabrics. Furthermore, the water-repellent property and thermal insulation properties were evaluated via the water contact angle and thermal conductivity tests, respectively, and the results showed that 20 wt.% SiO2/PVDF fabric achieved a desirable level of contact angle, 136.6°, which was the largest water contact angle among all the samples, and the lowest thermal conductivity of 0.033 W/mK, resulting from the existence of SiO2 nanoparticles. Such a fast and simple spray-coating strategy could be widely introduced into asymmetric fabric modification, and such asymmetric fabrics with reasonable water-repellent and thermal insulating outer surfaces could act as candidates in the field of functional garments.

scholarly journals Development of Superhydrophobic Polyester (Polyethylene terephthalate) Fabric for Multiple Applications

2020 ◽  
Vol 2 (2) ◽  
Author(s):  
Subhas Ghosh ◽  
Roopkatha Pallye
Keyword(s):  
Contact Angle ◽  
Water Contact Angle ◽  
Polyester Fabric ◽  
Ftir Analysis ◽  
Water Contact ◽  
Abrasion Test ◽  
Static Water Contact Angle ◽  
Static Water ◽  
Polyester Textile ◽  
Textile Fabric

This study intended to develop a healthy and environmentally friendly super-hydrophobic PET polyester textile fabric using a specific Fluoro Silane finish (SHF). A novel SHF was prepared and applied on a polyester fabric using a pad-dry-cure method. The finished fabric was evaluated for the degree of hydrophobicity, durability and stain repellence. The finished fabric exhibited static water contact angle greater than 170o and received 90 AATCC (4 ISO) rating that is recognized as super-hydrophobicity and this property was maintained even after a 50,000-cycle abrasion test. FTIR analysis identified the characteristic peaks related to Si-O-Si and C-F asymmetric stretching bands of the finish on the fabric indicating a robust attachment on the fabric. Finished fabric did not show any change in appearance or tactile characteristics of the fabric. 

Antigen detection with thermosensitive hydrophilicity of poly(N-isopropylacrylamide)-grafted poly(vinyl chloride) fibrous mats

2018 ◽  
Vol 6 (21) ◽  
pp. 3486-3496 ◽  
Author(s):  
Jian-Wei Guo ◽  
Zhen-Yu Lin ◽  
Bohr-Ran Huang ◽  
Chien-Hsing Lu ◽  
Jem-Kun Chen
Keyword(s):  
Contact Angle ◽  
Vinyl Chloride ◽  
Water Contact Angle ◽  
Antigen Detection ◽  
Stimuli Responsive ◽  
Water Contact ◽  
Static Water Contact Angle ◽  
Poly Vinyl Chloride ◽  
Static Water

The static water contact angle of stimuli-responsive fibrous mats is used as a convenient index for rapid antigen detection.

scholarly journals Nanocomposite Film Based on Cellulose Acetate and Lignin-Rich Rice Straw Nanofibers

Materials ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 595 ◽  
Author(s):  
Mohammad Hassan ◽  
Linn Berglund ◽  
Ragab Abou-Zeid ◽  
Enas Hassan ◽  
Wafaa Abou-Elseoud ◽  
...  
Keyword(s):  
Contact Angle ◽  
Cellulose Acetate ◽  
Rice Straw ◽  
Water Vapor Permeability ◽  
Light Transmittance ◽  
Vapor Permeability ◽  
Water Contact ◽  
Transparent Films ◽  
Force Microscopy ◽  
Good Transparency

Nanofibers isolated from unbleached neutral sulfite rice straw pulp were used to prepare transparent films without the need to modify the isolated rice straw nanofibers (RSNF). RSNF with loading from 1.25 to 10 wt.% were mixed with cellulose acetate (CA) solution in acetone and films were formed by casting. The films were characterized regarding their transparency and light transmittance, microstructure, mechanical properties, crystallinity, water contact angle, porosity, water vapor permeability, and thermal properties. The results showed good dispersion of RSNF in CA matrix and films with good transparency and homogeneity could be prepared at RSNF loadings of less than 5%. As shown from contact angle and atomic force microscopy (AFM) measurements, the RSNF resulted in increased hydrophilic nature and roughness of the films. No significant improvement in tensile strength and Young’s modulus was recorded as a result of adding RSNF to CA. Addition of the RSNF did not significantly affect the porosity, crystallinity and melting temperature of CA, but slightly increased its glass transition temperature.

On Antireflective Coatings with Stable Hydrophobicity for Solar Tube

2013 ◽  
Vol 423-426 ◽  
pp. 443-447 ◽  
Author(s):  
Wen Wen Dou ◽  
Yu Chao Niu ◽  
Xiang Ju Liu ◽  
Xiao Li Wang ◽  
Yong Xu
Keyword(s):  
Contact Angle ◽  
Low Temperature ◽  
Water Contact Angle ◽  
Prolonged Exposure ◽  
Sol Gel ◽  
High Porosity ◽  
Antireflective Coatings ◽  
Water Contact ◽  
Static Water Contact Angle ◽  
Static Water

Antireflective coatings with stable hydrophobicity for solar tube were prepared via sol-gel method and hexamethyldisilazane (HMDS) treatment. The coatings have a high porosity, groove-like surface morphology and a big static water contact angle. As a result, the coatings exhibit high transmittance even in high humidity environments. The transmittance peak can reach up to 99.02% which increased by 7% compared with the substrate and the wavelength band increased by more than 5% is from 438nm to 1000nm. After prolonged exposure to strong ultraviolet (UV) irradiation, the static water contact angle of the HMDS treated antireflective coatings decreased very small from 102o to 98o. In addition, the low-temperature tests showed the contact angle did not decline even at-50°C. The results suggest that the coatings prepared in present paper have stable hydrophobic and antireflective performance in the environment of strong UV radiation and low temperature.

Antibacterial and biological properties of coconut oil loaded poly(ε-caprolactone)/gelatin electrospun membranes

2021 ◽  
pp. 152808372199159 ◽  
Author(s):  
Parian S Mohamadi ◽  
Ahmad Hivechi ◽  
Hajir Bahrami ◽  
Nahid hemmatinegad ◽  
Peiman B Milan
Keyword(s):  
Antibacterial Activity ◽  
Water Vapor ◽  
Coconut Oil ◽  
Water Vapor Permeability ◽  
Biological Properties ◽  
Morphological Properties ◽  
Vapor Permeability ◽  
Crosslinking Reaction ◽  
Water Contact ◽  
Bio Oil

Coconut oil (CO) is a naturally derived bio-oil which exhibits specific characteristics such as biocompatibility and antibacterial activity. In this work, the biological properties of poly(caprolactone)/gelatin (PCL/Gel) nanofibers are improved using CO encapsulation. This bio-oil was added to the PCL/Gel polymer solution with different concentrations (5–40%). Nanofibers were crosslinked using glutaraldehyde vapor. Different types of characterization techniques such as SEM, FTIR, DSC, tensile measurements, water contact angle, and water vapor permeability were used to study the chemical, physical, thermal, and morphological properties of resultant nanofibers. Results showed an average diameter of 300–370 nm for as-spun nanofibers, which increased to 360–470 nm after the crosslinking reaction. The presence of CO was confirmed using FTIR and DSC experiments. Moreover, results indicated that the presence of CO increases the hydrophilicity and water vapor permeability of nanofibers, which are desirable for their final application. Biological tests, such as antibacterial activity, cell viability, and cell morphology tests were performed to evaluate the possible application of the produced nanofibers for wound healing applications. Results indicated that the crosslinked PCL/Gel nanofibers containing 20% CO exhibited the highest cell compatibility and antibacterial activity against gram-positive (S. aureus) and gram-negative ( E. coli) bacteria.

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