Study of contact angle, wettability and water vapor permeability in carboxymethylcellulose (CMC) based film with murta leaves (Ugni molinae Turcz) extract

2012 ◽  
Vol 109 (3) ◽  
pp. 424-429 ◽  
Author(s):  
Cristian Ramírez ◽  
Iciar Gallegos ◽  
Mónica Ihl ◽  
Valerio Bifani
Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 790
Author(s):  
Norhan Nady ◽  
Noha Salem ◽  
Sherif. H. Kandil

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.


Coatings ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 481
Author(s):  
Chen ◽  
Yi ◽  
Wu ◽  
Tan ◽  
Xu ◽  
...  

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.


2019 ◽  
pp. 152808371987127
Author(s):  
Meisam Salmani Sangtabi ◽  
Mehdi Kamali Dolatabadi ◽  
Mohsen Gorji ◽  
Ali Akbar Gharehaghaji ◽  
Abosaeed Rashidi

This study aimed to examine the fabrication of bi-constituent nanofibrous membranes and investigation of their moisture management behavior in various environmental conditions. In doing so, polyurethane with a hydrophobic nature and superior mechanical behavior and poly(2-acrylamido-2-methylpropane sulfonic acid) (PAMPS) with a hydrophilic nature were utilized. Different hybrid electrospun nanofibrous membranes were aligned based on different layer arrangements and composition ratios. Then, the impacts of the solid fraction of polymers, sequence of stacking, and environmental conditions on water vapor permeability, contact angle, and acidic water permeation were measured and discussed. Tracing the water vapor permeability behavior in samples was carried out through measuring the amount of permeation hourly and proposing some regression models. Bi-modal nanofibrous membranes were successfully fabricated using PAMPS and polyurethane with an average fiber diameter of 543.5 and 216.7 nm, respectively. As the volume fraction of PAMPS increased, the porosities of the samples remained unchanged, the number of pores increased, and the pore size decreased (the average pore diameter was 299.97 nm for the PAMPS sample and 492.35 nm for the polyurethane sample). Despite the better water vapor permeability of the polyurethane membranes than that of the PAMPS membranes, in the first 12 h of the water vapor permeability test, the trend was completely reverse. The results also revealed that in the relative humidity of 55%, the polyurethane layer had the highest water vapor permeability among all samples. The results of the acidic water permeation and contact angle tests showed that the hybrid electrospun nanofibrous membranes exhibit better wicking and wetting properties.


2014 ◽  
Vol 971-973 ◽  
pp. 81-84
Author(s):  
Yan Wu ◽  
Chun Sheng Chen ◽  
Yu Yue Qin ◽  
Jian Xin Cao

A novel antimicrobial poly (lactide) (PLA) film incorporated with clove essential oil (0, 2%, 4%, and 6% (w/v)) was developed. The mechanical property, water vapor permeability, color, contact angle, and antimicrobial activity of the films were investigated. The flexibility of films was improved by incorporation with clove. The water vapor permeability slightly increased with clove content. PLA film containing clove showed better antimicrobial activity compared to pure PLA film. The results suggested that PLA/clove blends could be a novel composite film for food packaging applications.


LWT ◽  
2007 ◽  
Vol 40 (8) ◽  
pp. 1473-1481 ◽  
Author(s):  
Valerio Bifani ◽  
Cristian Ramírez ◽  
Mónica Ihl ◽  
Mónica Rubilar ◽  
Alejandra García ◽  
...  

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jinshu Liu ◽  
Xiaoyan Ma ◽  
Wenzhao Shi ◽  
Jianwei Xing ◽  
Chaoqun Ma ◽  
...  

Abstract Baicalin, an active flavonoid ingredient of Scutellaria baicalensis Georgi, was extracted by heat reflux extraction and showed the same significance UV absorption property with standard baicalin. Active films were prepared from polyvinyl alcohol (PVA) containing baicalin extract by casting method. The effect of baicalin extracts on the UV-blocking, optical, antioxidant property, water vapor permeability, swelling and mechanical properties of the films were studied. UV–vis transmittance spectra showed that PVA films incorporated with baicalin extract blocked ultraviolet light range from 280–400 nm even with low concentration of baicalin (0.5 wt%) and maintain the high transparency in visible spectrum. The outstanding UV-blocking properties of PVA films incorporated with baicalin extract were also confirmed by Rhodamine B degradation. Baicalin conferred antioxidant properties to PVA films as determined by DPPH radical scavenging activity. Due to the interaction between hydroxy groups of baicalin and PVA molecule, water vapor permeability, swelling and elongation at break of the films were decreased accompanied with the increasing in tensile strength and Young’s modulus. FTIR reveal that the interaction between PVA molecules was significant changed by the introduction of baicalin. These results suggest that PVA film incorporated with baicalin extract can be used for the development of functional protective film.


Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 602
Author(s):  
Carmen Rodica Pop ◽  
Teodora Emilia Coldea ◽  
Liana Claudia Salanţă ◽  
Alina Lăcrămioara Nistor ◽  
Andrei Borşa ◽  
...  

Kefiran is an exopolysaccharide classified as a heteropolysaccharide comprising glucose and galactose in equimolar quantities, and it is classified as a water-soluble glucogalactan. This work aimed to investigate the effect of different extraction conditions of kefiran on the structural and physical properties of the edible films obtained. Fourier-transform infrared spectroscopy and scanning electron microscopy were performed, together with a determinations of moisture content, solubility, water vapor permeability and degree of swelling. The kefiran films presented values of the water vapor permeability between 0.93 and 4.38 × 10−11 g/m.s.Pa. These results can be attributed to the development of a more compact structure, where glycerol had no power to increase the free volume and the water vapor diffusion through their structure. The possible conformational changes in the kefiran film structure, due to the interspersing of the plasticizers and water molecules that they absorb, could be the reason for producing flexible kefiran films in the case of using glycerol as a plasticizer at 7.5% w/w. Moreover, it was observed that the extraction conditions are a significant factor in the properties of these films and their food technology applications.


Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3090
Author(s):  
Anita Ptiček Siročić ◽  
Ana Rešček ◽  
Zvonimir Katančić ◽  
Zlata Hrnjak-Murgić

The studied samples were prepared from polyethylene (PE) polymer which was coated with modified polycaprolactone (PCL) film in order to obtain bilayer films. Thin PCL film was modified with casein/aluminum oxide compound to enhance vapor permeability as well as mechanical and thermal properties of PE/PCL films. Casein/aluminum oxide modifiers were used in order to achieve some functional properties of polymer film that can be used in various applications, e.g., reduction of water vapor permeability (WVTR) and good mechanical and thermal properties. Significant improvement was observed in mechanical properties, especially in tensile strength as well as in water vapor values. Samples prepared with aluminum oxide particles indicated significantly lower values up to 60%, and samples that were prepared with casein and 5% Al2O3 showed the lowest WVTR value.


Author(s):  
Grégoire David ◽  
Laurent Heux ◽  
Stéphanie Pradeau ◽  
Nathalie Gontard ◽  
Hélène Angellier-Coussy

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.


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