scholarly journals Obtainment and Characterization of Hydrophilic Polysulfone Membranes by N-Vinylimidazole Grafting Induced by Gamma Irradiation

Polymers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1284
Author(s):  
Elizabeth Vázquez ◽  
Claudia Muro ◽  
Javier Illescas ◽  
Guillermina Burillo ◽  
Omar Hernández ◽  
...  
Keyword(s):  
Contact Angle ◽  
Gamma Irradiation ◽  
Membrane Surface ◽  
Absorbed Dose ◽  
Scanning Calorimetry ◽  
Membrane Degradation ◽  
Sem Images ◽  
Experimental Conditions ◽  
Water Contact ◽  
Swelling Degree

Polysulfone (PSU) film and N-vinylimidazole (VIM) were used to obtain grafted membranes with high hydrophilic capacity. The grafting process was performed by gamma irradiation under two experiments: (1) different irradiation doses (100–400 kGy) and VIM 50% solution; (2) different concentration of grafted VIM (30–70%) and 300 kGy of irradiation dose. Characteristics of the grafted membranes were determined by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), contact angle, swelling degree, desalination test, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Both experiments indicated that the absorbed dose 300 kGy and the VIM concentration, at 50% v/v, were effective to obtain PSU grafted membranes with 14.3% of grafting yield. Nevertheless, experimental conditions, 400 kGy, VIM 50% and 300 kGy, VIM 60–70% promoted possible membrane degradation and VIM homopolymerization on the membrane surface, which was observed by SEM images; meanwhile, 100–200 kGy and VIM 30–50% produced minimal grafting (2 ± 0.5%). Hydrophilic surface of the grafted PSU membranes by 300 kGy and VIM 50% v/v were corroborated by the water contact angle, swelling degree and desalination test, showing a decrease from 90.7° ± 0.3 (PSU film) to 64.3° ± 0.5; an increment of swelling degree of 25 ± 1%, and a rejection-permeation capacity of 75 ± 2%. In addition, the thermal behavior of grafted PSU membranes registered an increment in the degradation of 20%, due to the presence of VIM. However, the normal temperature of the membrane operation did not affect this result; meanwhile, the glass transition temperature (Tg) of the grafted PSU membrane was found at 185.4 ± 0.5 °C, which indicated an increment of 15 ± 1%.

scholarly journals Incorporation of Lipids into Wheat Bran Cellulose/Wheat Gluten Composite Film Improves Its Water Resistance Properties

Membranes ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 18
Author(s):  
Guanghui Shen ◽  
Guoxian Yu ◽  
Hejun Wu ◽  
Shanshan Li ◽  
Xiaoyan Hou ◽  
...  
Keyword(s):  
Composite Film ◽  
Wheat Bran ◽  
Food Packaging ◽  
Water Resistance ◽  
Wheat Gluten ◽  
Vapor Permeability ◽  
Scanning Calorimetry ◽  
Sem Images ◽  
Water Contact ◽  
Cross Sectional

This work evaluated the improvement effects of lipids incorporation on water resistance of composite biodegradable film prepared with wheat bran cellulose/wheat gluten (WBC/WG) using an alkaline–ethanol film forming system. Four types of lipids, paraffin wax (PW), beeswax (BW), paraffin oil (PO), and oleic acid (OA), were tested. We found that PW, BW, and PO incorporation at 5–20% improved water vapor permeability (WVP) and surface hydrophobicity of prepared films. Particularly, incorporation of 15% BW could best improve the water resistance properties of the film, with the lowest WVP of 0.76 × 10−12 g/cm·s·Pa and largest water contact angle (WCA) of 86.18°. Incorporation of OA led to the decline in moisture barrier properties. SEM images revealed that different lipids incorporation changed the morphology and of the composite film, and cross-sectional morphology indicated BW-incorporated film obtained more uniform and compact structures compared to other films. Moreover, Fourier transform infrared spectra indicated that the incorporation of PW or BW enhanced the molecular interactions between the film components, confirmed by the chemical shift of characteristic peaks at 3277 and 1026 cm−1. Differential scanning calorimetry results revealed that incorporation of PW, BW, and PO increased films’ melting point, decomposition temperatures, and enthalpy values. Furthermore, the presence of most lipids decreased tensile strength and elongation at the break of the film. Overall, the composite film containing 15% BW obtained the most promising water resistance performance and acceptable mechanical properties, and it thus most suitable as a hydrophobic biodegradable material for food packaging.

Colloidal characteristics of gelatin-treated clay: Intercalation, stability, wettability, and rheological properties

2021 ◽  
Vol 29 (9_suppl) ◽  
pp. S1361-S1370
Author(s):  
Xuwu Luo ◽  
Guancheng Jiang ◽  
Xinliang Li ◽  
Lili Yang
Keyword(s):  
Contact Angle ◽  
Particle Size ◽  
Rheological Properties ◽  
Water Contact Angle ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Water Contact ◽  
Ζ Potential ◽  
And Behavior ◽  
Clay Intercalation

In this paper, sodium montmorillonite was modified with gelatin of different concentrations, and various colloidal characteristics of the gelatin-treated clays were measured and analyzed in detail. First, the influence of gelatin on the interlayer space of Mt layers was investigated by X-ray diffraction analysis. Moreover, the aggregation of Mt particles was examined using a combination of electron microscopy and particle size distribution experiments, while the variation of the electrical property of Mt was measured using ζ potential test. Gelatin of different concentrations can increase the particle size of Mt in different degrees. The addition of 4% gelatin could improve the ζ potential of Mt from −30.65 to −15.55 mV. The wettability change of modified Mt induced by the adsorption of gelatin was followed by measurements of water contact angle and observations of the morphology of Mt/gelatin membrane through SEM images. 4% gelatin could improve the water contact angle of Mt to 81.3°. Finally, the rheological properties of Mt/gelatin dispersion including shear viscosity and shear stress were measured using a stress-controlled rheometer. All of the results were consistent by showing that the overall colloidal characteristics and behavior of the gelatin-treated Mt strongly varied depending on the gelatin concentration used in the modification process. These results can provide a deep and comprehensive understanding of the colloidal properties of clay/gelatin systems and give important guidance for the performance design and improvement of Mt/gelatin composite materials. Furthermore, this study can also be expanded the application of gelatin and its composites to other fields.

Preparation of Hydrophobic Nylon Fabric

2016 ◽  
Vol 11 (1) ◽  
pp. 155892501601100
Author(s):  
Jinmei Du ◽  
Lulu Zhang ◽  
Jing Dong ◽  
Ying Li ◽  
Changhai Xu ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Surface Energy ◽  
Water Contact Angle ◽  
Sem Images ◽  
Water Contact ◽  
Carboxyl Content ◽  
Factors Affecting ◽  
Nylon Fabric ◽  
Butanetetracarboxylic Acid

Surface roughness and surface energy are two important factors affecting the hydrophobicity of nylon fabric. In this study, nylon fabric was treated for hydrophobicity with tetrabutyltitanate (TBT) and octadecylamine (OA) which were respectively responsible for increasing surface roughness and reducing surface energy. In order to enhance the hydrophobicity, In order to further enhance hydrophobicity by increasing available reactive sites, 1,2,3,4–butanetetracarboxylic acid (BTCA) was applied as a pretreatment to the nylon fabric It was found that the carboxyl content of nylon was increased by the BTCA pretreatment. SEM images showed that the TBT treatment produced small particles on nylon fabric which made surface rough. The water contact angle of nylon fabric treated with BTCA, TBT and OA was measured to be 134°, which was much greater than the water contact angle of nylon fabric treated only with OA. This indicated that the surface roughness resulting from the TBT treatment played an important role in improving hydrophobicity of the treated nylon fabric. The resistance to water penetration and the repellency of water spray of nylon fabric treated with BTCA, TBT and OA were respectively measured to be 27.64 mbar and 85 out of 100.

scholarly journals The effect of the polar solvents on the synthesis of poly(urethane-urea-siloxane)s

2012 ◽  
Vol 77 (10) ◽  
pp. 1457-1481 ◽  
Author(s):  
Milica Balaban ◽  
Vesna Antic ◽  
Marija Pergal ◽  
Iolanda Francolini ◽  
Andrea Martinelli ◽  
...  
Keyword(s):  
Monomer Concentration ◽  
Gel Permeation Chromatography ◽  
Molar Ratio ◽  
Solvent Ratio ◽  
Solvent Mixtures ◽  
Scanning Calorimetry ◽  
Experimental Conditions ◽  
Water Contact ◽  
Soft Segments ◽  
Hard Segments

Segmented poly(urethane-urea-siloxanes) (PUUS) based on 4,4?- methylene diphenyl diisocyanate-ethylene diamine (MDI-ED) hard segments and hidroxypropyl-terminated poly(dimethylsiloxane) (PDMS, M n =1000 g mol-1) soft segments were prepared under various experimental conditions. The copolymers with constant molar ratio of hard and soft segments (PDMS:MDI:ED = 1:2:1; 20 wt. % of the hard segments) were synthesized in two different solvent mixtures, by two-step polyaddition procedure. The first one was THF/DMAc with different co-solvent ratio (1/1, 1/2 and 1/9, v/v), whereas the second one was THF/NMP (1/9, v/v). The reaction conditions were optimized by varying the co-solvents ratio, the concentration of the catalyst, the initial monomer concentration, as well as the time of the first and the second step of reaction. The effect of the experimental conditions on the size of PUUS was investigated by gel permeation chromatography (GPC) and viscometry of the dilute solutions [?]. The copolymers with the highest molecular weights were obtained in the THF/NMP mixture (1/9, v/v). The structure and composition of the copolymers were determined by 1H NMR and FTIR spectroscopy. The morphology of the synthesized copolymers was investigated by atomic force microscopy (AFM), while the thermal properties were studied by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The surface properties were evaluated by measuring the water contact angle (WCA). The copolymers showed phase separated microstructure and were stable up to 200?C in nitrogen.

scholarly journals ENHANCING HYDROPHILICITY OF POLYSULFONE MEMBRANE SURFACE BY UV IRRADIATION OF DIFFERENT WAVELENGTHS AND BY PEG GRAFTING

2021 ◽  
Vol 83 (4) ◽  
pp. 111-117
Author(s):  
Soraya Ruangdit ◽  
Suksawat Sirijaruku ◽  
Thawat Chittrakarn ◽  
Chaiporn Kaew-on
Keyword(s):  
Contact Angle ◽  
Membrane Surface ◽  
Water Flux ◽  
Separation Performance ◽  
Poly Ethylene Glycol ◽  
Uv Treatment ◽  
Water Contact ◽  
Polysulfone Membrane ◽  
Membrane Surfaces ◽  
Poly Ethylene

Polysulfone polymer (PSF) membrane has disadvantages due to its hydrophobicity, which may cause fouling and reduce separation performance. Therefore, this study aimed to enhance the hydrophilicity of PSF membranes by using irradiation at different ultraviolet (UV) wavelengths, followed by Poly(ethylene glycol) (PEG) grafting on the PSF surfaces. The hydrophilicity of the treated membrane surfaces was examined by measuring water contact angle (WCA), surface energy (SE), surface morphology, functional groups, salt rejection, and water flux in a filtration instrument. The results show that with long UV treatment for up to 72 h, the 312 nm wavelength gave lesser WCA than treatment at 254 nm. The treated PSF membrane irradiated at 312 nm for 72 h, followed by PEG grafting, was effectively improved and retained increased hydrophilicity for up to thirty days.

scholarly journals Fabrication of Bentonite–Silica Sand/Suspended Waste Palm Leaf Composite Membrane for Water Purification

Membranes ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 290
Author(s):  
Saad A. Aljlil
Keyword(s):  
Contact Angle ◽  
Pore Size ◽  
Average Pore Size ◽  
Membrane Surface ◽  
Ceramic Membranes ◽  
Suspended Solid ◽  
Silica Sand ◽  
Distribution Analysis ◽  
Average Pore ◽  
Water Contact

In this study, a method for fabricating tubular ceramic membranes via extrusion using economical and locally available bentonite–silica sand and waste palm leaves was developed as a tool for conducting the necessary task of purifying water polluted with oil and suspended solid materials produced via various industrial processes. The developed tubular ceramic membranes were found to be highly efficient at separating the pollutants from water. The properties of the fabricated membrane were evaluated via mechanical testing, pore size distribution analysis, and contact angle measurements. The water contact angle of the fabricated membrane was determined to be 55.5°, which indicates that the membrane surface is hydrophilic, and the average pore size was found to be 66 nm. The membrane was found to demonstrate excellent corrosion resistance under acidic as well as basic conditions, with weight losses of less than 1% in each case. The membrane surface was found to be negatively charged and it could strongly repulse the negatively charged fine bentonite particles and oil droplets suspended in the water, thereby enabling facile purification through backwashing. The obtained ceramic membranes with desirable hydrophilic properties can thus serve as good candidates for use in ultrafiltration processes.

Improving the Surface Wettability of Parylene C Film by Hyperthermal Hydrogen Induced Cross-Linking Technology

2015 ◽  
Vol 1120-1121 ◽  
pp. 64-67
Author(s):  
Hong Shao ◽  
Chang Yu Tang ◽  
Mao Bing Shuai ◽  
Ke Qing Xu ◽  
Yuan Lin Zhou ◽  
...  
Keyword(s):  
Contact Angle ◽  
Water Contact Angle ◽  
Membrane Surface ◽  
Surface Wettability ◽  
Cross Linking ◽  
Surface Chemical ◽  
Water Contact ◽  
Parylene C ◽  
Wetting Property ◽  
Polar Functional Groups

In this paper, we present a new approachcalled hyperthermal hydrogen induced cross-linking (HHIC) technology,which can successfully enhance the surface wettability of Parylene C (PC) film via cross-linking hydrophilic polyacrylic acid（PAA）on its surface. Water Contact Angle Meter and Fourier Transform Infrared Spectroscopy (FTIR) were used to characterize wetting property, surface chemical structureof PC film before or after HHIC treatment,respectively. The results show that PAA with polar functional groups can be successfully grafted onto the PC film. As a result, the water contact angle of the modified PC membrane surface decreased from 84° to 23°,PC membrane surface wettability is improved effectively.

scholarly journals Highly thermally resistant hydrophobic poly(vinyl alcohol)-silica hybrid nanofibers

2018 ◽  
Vol 83 (7-8) ◽  
pp. 885-897
Author(s):  
Ugur Hulusi ◽  
Burcu Oktay ◽  
Atilla Gungor ◽  
Nilhan Kayaman-Apohan
Keyword(s):  
Contact Angle ◽  
Water Contact Angle ◽  
Vinyl Alcohol ◽  
Sol Gel ◽  
Poly Vinyl Alcohol ◽  
Water Mixture ◽  
Sem Images ◽  
Water Contact ◽  
Hybrid Nanofibers ◽  
Silica Precursor

In this paper, the preparation of hydrophobic and crosslinked poly- (vinyl alcohol)/silica organic?inorganic hybrid nanofibers via the sol?gel electrospinning method is reported. Silica was produced through the acetic acid catalyzed reaction of a silica precursor consisting of dimethyldimethoxysilane (DMDMOS), methyltrimethoxysilane (MTMS), tridecafluoro-1,1,2,2-tetrahydrooctyltriethoxysilane (FAS1313; Dynasylan? F 8261) and phenyltrimethoxysilane (PTMS; Dynasylan? 9165) in a 2-propanol?water mixture. Hybrid nanofibers were obtained by electrospinning the silica precursor and an aqueous PVA solution. Chemical, structural, thermal and surface analyses were conducted by Fourier-transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy/energy-dispersive X-ray (SEM/EDX) and water contact angle (WCA) methods, respectively. The obtained hybrid nanofibers were insoluble in aqueous solution. SEM images displayed that highly crosslinked and porous structures were obtained and the average fiber diameters of poly(vinyl alcohol) (PVA)/silica nanocomposites were around 70 nm. A nanofiber surface with a water contact angle of 130? was achieved.

scholarly journals Preparation and Characterization of Polyhedral Octaphenylsilsesquioxane Modified Castor oil based Polyurethane

2018 ◽  
Vol 20 (1) ◽  
pp. 16-25
Author(s):  
Yue Wen ◽  
Pingping Jiang ◽  
Jie Huang ◽  
Agus Haryono ◽  
Jianneng Deng ◽  
...  
Keyword(s):  
Contact Angle ◽  
Castor Oil ◽  
Surface Hydrophobicity ◽  
Decomposition Temperature ◽  
Nano Particles ◽  
Scanning Calorimetry ◽  
Sem Images ◽  
Initial Decomposition Temperature ◽  
Static Contact ◽  
Infrared Spectrometer

Vegetable oil-based polyurethanes were synthesized using castor oil (CO) as feedstock, which were characterized by their environmental friendly and renewable properties. Aiming to compensate for shortcomings of these materials, a series of polyurethane/polyhedral octaphenylsilsesquioxane (OPS) hybrids with different OPS contents were prepared by physical mixing in the solutions. Thereafter?chemical structure?morphology and thermal properties of hybrids were characterized through Fourier transform infrared spectrometer (FTIR), scanning electron microscope (SEM), differential scanning calorimetry (DSC), thermal gravimetric analyzer (TGA), tensile test techniques and static contact angle. The results show that the hybrid polyurethanes display both enhanced glass transition temperatures (Tg), initial decomposition temperature (Td5) and tensile strength with low OPS contents. While with high contents?these values decline with the severe aggregation of nano-particles as shown in the SEM images. Meanwhile, the hybrid polyurethanes displayed enhanced surface hydrophobicity as the contact angle with water revealed

Study on the Conditions of Plasma-Induced Graft Acrylic Acid on Polyethersulfone Substrates

2012 ◽  
Vol 627 ◽  
pp. 791-795
Author(s):  
Ru Li ◽  
Fen Fen Liu ◽  
Ji Fei Deng
Keyword(s):  
Contact Angle ◽  
Acrylic Acid ◽  
Plasma Treatment ◽  
Water Contact Angle ◽  
Surface Composition ◽  
Treatment Time ◽  
Membrane Surface ◽  
Water Contact ◽  
Plasma Treatment Time ◽  
Low Temperature Plasmas

The use of low-temperature plasmas to modify the surface of substrates and grafted acrylic acid is discussed. Their surface composition characterized by attenuated total reflectance fourier transform infrared (ATR-FTIR) spectra and water contact angle. The results of various techniques indicated that acrylic acid could be incorporated in the membrane surface. The plasma treatment time，plasma treatment power and grafting time effect on water contact angle. The water contact angle decreased from 67° for virgin PES to 11° for the plasma-induced and 0° for grafted AA.

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