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.

scholarly journals Investigation of the Effects of Component Ratios on the Properties of Superhydrophobic Polyurethane/Fluorinated Acrylic Co-Polymer/SiO2 Nanocomposite Coatings

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 174
Author(s):  
Chong Ke ◽  
Zhongfa Li ◽  
Chenhua Zhang ◽  
Xinguo Wu ◽  
Zhiping Zhu ◽  
...  
Keyword(s):  
Contact Angle ◽  
Water Contact Angle ◽  
Abrasion Resistance ◽  
Light Transmittance ◽  
Practical Application ◽  
Water Contact ◽  
Glass Substrates ◽  
Superhydrophobic Coatings ◽  
One Step ◽  
Good Transparency

In this work, polyurethane/fluorinated acrylic co-polymer/silicon dioxide (PU/FAP/SiO2) hybrid superhydrophobic coatings were fabricated on glass substrates via a simple one-step coating process. The effects of each coating component on the coating properties were systematically investigated. The optimized coating exhibits a water contact angle (WCA) of 159° and a rolling angle of 3°. Meanwhile, the coating has an optical light transmittance of 88%, indicating the good transparency of the coating. Besides, the coating demonstrates an adequate level of abrasion resistance. After a total abrasion distance of 300 cm against a piece of 800 mesh sand paper, the sample still kept a water contact angle of about 110°, showing its high abrasion resistance. Therefore, the optimized coating has a great potential for practical application.

scholarly journals An Easy Route to Wettability Changes of Polyethylene Terephthalate–Silicon Oxide Substrate Films for High Barrier Applications, Surface-Modified with a Self-Assembled Monolayer of Fluoroalkylsilanes

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 257 ◽  
Author(s):  
Paola Scarfato ◽  
Nicola Schiavone ◽  
Gabriella Rossi ◽  
Loredana Incarnato
Keyword(s):  
Contact Angle ◽  
Polyethylene Terephthalate ◽  
Silicon Oxide ◽  
Film Surface ◽  
Water Vapor Permeability ◽  
Vapor Permeability ◽  
Self Assembled Monolayer ◽  
Water Contact ◽  
Oxide Substrate ◽  
Self Assembled

Inorganic–organic multilayer films consisting of polymers coated with thin inorganic oxidic layers (e.g., SiOx) ensure very high barrier performances against gas and vapor permeation, what makes them packaging materials suitable for sophisticated technical applications, including the encapsulation of photovoltaic devices or quantum dots, barrier films for optical displays, and transparent greenhouse screens. In these fields, surface coating or texturing of the multilayer protective films are effective technologies to improve their self-clean ability, thus reducing the required maintenance and ensuring longer durability and better performances. In this work, we used the self-assembled monolayer (SAM) technique to modify the surface and wetting properties of commercial polyethylene terephthalate-silicon oxide substrate (PET-SiOx) films developed for technical applications requiring a combined high barrier and transparency. The selected surface modifier was the 1H,1H,2H,2H-per-fluorodecyltrichlorosilane (FDTS). The reagent mixture composition was optimized for the lowest water and oil wettability, as well as the highest self-cleaning capacity and performance stability. In particular, for the used PET-SiOx film the best FDTS/film surface for both the lowest water and oil wettability was found to be equal to 26.5 mM/dm2, which changes the surface behavior from very hydrophilic (static water contact angle (CAw) = 21.5°) to hydrophobic (CAw = 101°), and gives a significant increment of the static oil contact angle (CAo) from 27° to 60°. Interestingly, the results demonstrated that the SAM reaction occurred also on the uncoated the PET side. After the SAM treatment, a small increase of the water vapor permeability is observed, probably due to a crack or defect onset of the SiOx coating of the SAM modified films. On this point, atomic force measurements demonstrated an increment of the SiOx coating layer roughness after the SAM treatment execution. Finally, the transparency changes of the SAM treated films, measured in the wavelength range 400–800 nm, were always small, so that the results were acceptable for the films’ use in applications where high transparency is required.

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.

Surface Properties of Superhydrophobic Coatings for Stone Protection

2009 ◽  
Vol 8 ◽  
pp. 23-33 ◽  
Author(s):  
P.N. Manoudis ◽  
I. Karapanagiotis ◽  
A. Tsakalof ◽  
I. Zuburtikudis ◽  
B. Kolinkeová ◽  
...  
Keyword(s):  
Contact Angle ◽  
Water Vapor Permeability ◽  
Sio2 Nanoparticles ◽  
Vapor Permeability ◽  
Capillary Absorption ◽  
Sem Images ◽  
Water Contact ◽  
Static Contact ◽  
Colorimetric Measurements ◽  
Glass Surfaces

Superhydrophobic films are produced by a simple and low cost method. Silica (SiO2) nanoparticles are dispersed in solutions of Rhodorsil 224, a commercial poly(alkyl siloxane) which is used for the protection of outdoor cultural heritage objects, and the suspensions are sprayed on glass surfaces. It is shown that the siloxane-nanoparticle composite films prepared from dispersions of high particle concentrations (≥ 0.5% w/v) exhibit superydrophobic properties (high static contact angle and small hysteresis) which can be rationalized by the Cassie-Baxter model, according to quantitative measurements obtained by SEM images. Siloxane-nanoparticle films are then deposited (sprayed) on “Opuka”, a fine-grained argillite which was used for the restoration of the castle of Prague. It is shown that the treated stone surfaces exhibit superydrophobic properties, similar to the treated glass surfaces. The efficacy of the superhydrophobic films to protect Opuka is evaluated by performing water contact angle, water capillary absorption, water vapor permeability and colorimetric measurements. It is shown that the use of nanoparticles in the protective coating has a positive effect on the results of the aforementioned tests, except for the colorimetric measurements.

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.

scholarly journals Improving the Performance of Feather Keratin/Polyvinyl Alcohol/Tris(hydroxymethyl)Aminomethane Nanocomposite Films by Incorporating Graphene Oxide or Graphene

Nanomaterials ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 327 ◽  
Author(s):  
Shufang Wu ◽  
Xunjun Chen ◽  
Tiehu Li ◽  
Yingde Cui ◽  
Minghao Yi ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Polyvinyl Alcohol ◽  
Water Vapor Permeability ◽  
Nanocomposite Films ◽  
Light Transmittance ◽  
Vapor Permeability ◽  
Blend Films ◽  
Feather Keratin ◽  
Degradation Temperature ◽  
Bionanocomposite Films

In this study, feather keratin/polyvinyl alcohol/tris(hydroxymethyl)aminomethane (FK/PVA/Tris) bionanocomposite films containing graphene oxide (GO) (0.5, 1, 2, and 3 wt%) or graphene (0.5, 1, 2, and 3 wt%) were prepared using a solvent casting method. The scanning electron microscopy results indicated that the dispersion of GO throughout the film matrix was better than that of graphene. The successful formation of new hydrogen bonds between the film matrix and GO was confirmed through the use of Fourier-transform infrared spectroscopy. The tensile strength, elastic modulus, and initial degradation temperature of the films increased, whereas the total soluble mass, water vapor permeability, oxygen permeability, and light transmittance decreased following GO or graphene incorporation. In summary, nanoblending is an effective method to promote the application of FK/PVA/Tris-based blend films in the packaging field.

scholarly journals Preparation and Properties of Corn Starch/Chitin Composite Films Cross-Linked by Maleic Anhydride

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1606
Author(s):  
Peng Yin ◽  
Jinglong Liu ◽  
Wen Zhou ◽  
Panxin Li
Keyword(s):  
Maleic Anhydride ◽  
Corn Starch ◽  
Composite Films ◽  
Water Vapor Permeability ◽  
Contact Angles ◽  
Vapor Permeability ◽  
Water Contact ◽  
Elongation At Break ◽  
Shrimp Shell ◽  
Starch Films

To improve the functional properties of starch-based films, chitin (CH) was prepared from shrimp shell powder and incorporated into corn starch (CS) matrix. Before blending, maleic anhydride (MA) was introduced as a cross-linker. Composite CS/MA-CH films were obtained by casting-evaporation approach. Mechanical property estimation showed that addition of 0–7 wt % MA-CH improved the tensile strength of starch films from 3.89 MPa to 9.32 MPa. Elongation at break of the films decreased with the addition of MA-CH, but the decrease was obviously reduced than previous studies. Morphology analysis revealed that MA-CH homogeneously dispersed in starch matrix and no cracks were found in the CS/MA-CH films. Incorporation of MA-CH decreased the water vapor permeability of starch films. The water uptake of the films was reduced when the dosage of MA-CH was below 5 wt %. Water contact angles of the starch films increased from 22° to 86° with 9 wt % MA-CH incorporation. Besides, the composite films showed better inhibition effect against Escherichia coli and Staphylococcus aureus than pure starch films.

scholarly journals Improving Thermal, Mechanical, and Barrier Properties of Feather Keratin/Polyvinyl Alcohol/Tris(hydroxymethyl)aminomethane Nanocomposite Films by Incorporating Sodium Montmorillonite and TiO2

Nanomaterials ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 298 ◽  
Author(s):  
Shufang Wu ◽  
Xunjun Chen ◽  
Minghao Yi ◽  
Jianfang Ge ◽  
Guoqiang Yin ◽  
...  
Keyword(s):  
Polyvinyl Alcohol ◽  
Three Dimensional ◽  
Water Vapor Permeability ◽  
Barrier Properties ◽  
Nanocomposite Films ◽  
Light Transmittance ◽  
Vapor Permeability ◽  
Hydroxyl Groups ◽  
Sodium Montmorillonite ◽  
Feather Keratin

In this study, feather keratin/polyvinyl alcohol/tris(hydroxymethyl)aminomethane (FK/PVA/Tris) bionanocomposite films containing two types of nanoparticles, namely one-dimensional sodium montmorillonite (MMT) clay platelets (0.5, 1, 3, and 5 wt%) and three-dimensional TiO2 nanospheres (0.5, 1, 3, and 5 wt%), are prepared using solvent casting method. X-ray diffraction studies confirm the completely exfoliated structure of FK/PVA/Tris/MMT nanocomposites. The successful formation of new hydrogen bonds between the hydroxyl groups of the film matrix and the nanofillers is confirmed by Fourier transform infrared spectroscopy. The tensile strength, elongation at break, and initial degradation temperature of the films are enhanced after MMT and TiO2 incorporation. The water vapor permeability, oxygen permeability, and light transmittance decrease with increase in TiO2 and MMT contents. In summary, nanoblending is an effective method to promote the application of FK/PVA/Tris blend films in the packaging field.

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