scholarly journals Water and oil resistance improvement of paper coated with aqueous mixture of hydrophilic and hydrophobic cross-linked copolymers

BioResources ◽  
2020 ◽  
Vol 15 (2) ◽  
pp. 3147-3160
Author(s):  
Zhaoping Song ◽  
Jiebin Tang ◽  
Huili Wang ◽  
Feixiang Guan ◽  
Yutao Wu ◽  
...  

An aqueous mixture of hydrophilic and hydrophobic cross-linked copolymers was prepared and coated on the surface of filter paper to improve the water and oil resistances. The mixture was mainly composed of sodium alginate and hydroxyl-terminated polydimethylsiloxane (PDMS)-tetramethoxysilane (TMOS) cross-linked network. The results indicated that the resistances to both water and oil of the resulting paper were significantly enhanced. The water contact angle results demonstrated that the mixture enhanced the hydrophobic properties of the coated paper greatly with water contact angles higher than 110°, and the coated paper showed excellent oil resistance with a Kit number as high as 10.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ahmed S. Belal ◽  
Jehan El Nady ◽  
Azza Shokry ◽  
Shaker Ebrahim ◽  
Moataz Soliman ◽  
...  

AbstractOily water contamination has been sighted as one of the most global environmental pollution. Herein, copper hydroxide nanorods layer was constructed onto cellulosic filter paper surface cured with polydopamine, Ag nanoparticles, and Cu NPs through immersion method. This work has been aimed to produce a superhydrophobic and superoleophilic cellulosic filter paper. The structure, crystalline, and morphological properties of these modified cellulosic filter paper were investigated. Scanning electron microscope images confirmed that the modified surface was rougher compared with the pristine surface. The contact angle measurement confirmed the hydrophobic nature of these modified surfaces with a water contact angle of 169.7°. The absorption capacity was 8.2 g/g for diesel oil and the separation efficiency was higher than 99%. It was noted that the flux in the case of low viscosity solvent as n-hexane was 9663.5 Lm−2 h−1, while for the viscous oil as diesel was 1452.7 Lm−2 h−1.


BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 5794-5805
Author(s):  
Yating Wang ◽  
Xiaochun Chen ◽  
Yaqi Liang ◽  
Chenghua Yu

Despite previous efforts, the fabrication of superhydrophobic substrate via an environment friendly and easy approach remains a great challenge. In this study, a low cost, simple, and green procedure was developed to prepare a superhydrophobic paper surface that is acceptable for the papermaking industry. First, a wax mixture (beeswax & carnauba wax) was emulsified and coated on the filter paper surface. Then, the coated paper was annealed at different temperatures. The further heat-treatment-rendered wax-coated paper hydrophobic or superhydrophobic because submicrometer or micrometer wax structures were present on the paper surface. The water contact angle of the annealed filter paper sample reached 151.5° at 60 °C, and the sliding angle was under 10°. Further, the relationship between surface composition and the hydrophobic properties of the coated paper samples was discussed. The obtained paper samples showed great potential in water/oil separation, as they had an efficiency over 99%. This work proposed a new simple and mild approach to fabricate superhydrophobic filter papers and explored the hydrophobicity and water/oil separation properties.


2012 ◽  
Vol 562-564 ◽  
pp. 56-59 ◽  
Author(s):  
Jian Zhuang ◽  
Meng Meng Du ◽  
Heng Zhi Cai ◽  
Ya Jun Zhang ◽  
Da Ming Wu

A facile method for manufacturing super hydrophobic surfaces is presented using the stainless steel wire mesh as templates. The rough surfaces of polymers including polycarbonate, polypropylene and PMMA are prepared with hot embossing on different specifications of stainless steel wire mesh. Scanning electron microscopy (SEM) results reveal that the surfaces roughness of the polymers can be controlled by selecting templates. Contact angle measurement shows that the water contact angles(WCA) rise with the increase of surface roughness, especially, the water contact angle on the PC surfaces prepared with specifications of 635mesh screen can reach to 152.3°, alias super hydrophobic surfaces.


Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 471 ◽  
Author(s):  
Martha Claros ◽  
Milena Setka ◽  
Yecid P. Jimenez ◽  
Stella Vallejos

Non-modified (ZnO) and modified (Fe2O3@ZnO and CuO@ZnO) structured films are deposited via aerosol assisted chemical vapor deposition. The surface modification of ZnO with iron or copper oxides is achieved in a second aerosol assisted chemical vapor deposition step and the characterization of morphology, structure, and surface of these new structured films is discussed. X-ray photoelectron spectrometry and X-ray diffraction corroborate the formation of ZnO, Fe2O3, and CuO and the electron microscopy images show the morphological and crystalline characteristics of these structured films. Static water contact angle measurements for these structured films indicate hydrophobic behavior with the modified structures showing higher contact angles compared to the non-modified films. Overall, results show that the modification of ZnO with iron or copper oxides enhances the hydrophobic behavior of the surface, increasing the contact angle of the water drops at the non-modified ZnO structures from 122° to 135° and 145° for Fe2O3@ZnO and CuO@ZnO, respectively. This is attributed to the different surface properties of the films including the morphology and chemical composition.


2019 ◽  
Vol 798 ◽  
pp. 385-390
Author(s):  
Sunisa Jindasuwan ◽  
Sitthisuntorn Supothina

The separation of oil from water is significance for environmental de-pollution application. To obtain selectivity of liquid, filter papers were coated to bear highly hydrophobic and oleophilic functionality that can allow only oils to pass through them. The coating solutions were prepared by mixing poly(methylhydro siloxane, PMHS) and fumed silica at various proportions. To determine an optimum coating condition, properties of the treated filter papers were investigated by measuring water contact angle and surface free energy, examining surface morphology and testing for selective removal of diesel oil from water. The optimum coating solution was at the PMHS:fumed silica weight ratio of 1.25:1.00. The treated filter paper exhibited high hydrophobicity with water contact angle of 142.80 ± 0.36 degrees and surface free energy of 0.78 mJ/m2. In addition, it exhibited high selective removal of diesel oil from water with oil absorption capacity of 2.3 g/g.


1995 ◽  
Vol 383 ◽  
Author(s):  
M. R. Houston ◽  
R. T. Howe ◽  
K Komvopoulos ◽  
R. Maboudian

ABSTRACTThe surface properties of diamond-like carbon (DLC) films deposited by a vacuum arc technique on smooth silicon wafers are presented with specific emphasis given to stiction reduction in microelectromechanical systems (MEMS). The low deposition temperatures afforded by the vacuum arc technique should allow for easy integration of the DLC films into the current fabrication process of typical surface micromachines by means of a standard lift-off processing technique. Using X-ray photoelectron spectroscopy (XPS), contact angle analysis, and atomic force microscopy (AFM), the surface chemistry, microroughness, hydrophobicity, and adhesion forces of DLC-coated Si(100) surfaces were measured and correlated to the measured water contact angles. DLC films were found to be extremely smooth and possess a water contact angle of 87°, which roughly corresponds to a surface energy of 22 mJ/m2. It is shown that the pull-off forces measured by AFM correlate well with the predicted capillary forces. Pull-off forces are reduced on DLC surfaces by about a factor of five compared to 10 nN pull-off forces measured on the RCA-cleaned silicon surfaces. In the absence of meniscus forces, the overall adhesion force is expected to decrease by over an order of magnitude to the van der Waals attractive force present between two DLC-coated surfaces- To further improve the surface properties of DLC, films were exposed to a fluorine plasma which increased the contact angle to 99° and lowered the pull-off force by approximately 20% over that obtained with as-deposited DLC. The significance of these results is discussed with respect to stiction reduction in micromachines.


2012 ◽  
Vol 627 ◽  
pp. 849-854 ◽  
Author(s):  
Ching Wen Lou ◽  
Chao Tsang Lu ◽  
Jin Jia Hu ◽  
Wei Jen Lin ◽  
Meng Chen Lin ◽  
...  

Polymer materials such as sodium alginate, chitosan, polylactic acid, and pectin, are commonly used as biomedical materials. This study combines sodium alginate (SA) and chitosan solutions to make the compound membranes. The compound membranes with optimal parameters are then combined with base fabrics, forming the compound dressings. SA and chitosan are mixed with various ratios, and then added with calcium chloride (CaCl2 (aq)), after which the mixture is thermally treated to form the SA/chitosan compound membranes. Moisture retention, swelling, weight loss, water contact angle, and water content ratio tests evaluate the resulting membranes, determining the optimum parameters. When the ratio of SA to chitosan is 7:3, the resulting membranes exhibit an optimal swelling. The weight loss of the membranes starts decreasing with the addition of CaCl2 (aq), indicating an increase in the structural stability of the compound membranes. Lastly, the water contact angle of all compound membranes is smaller than 90°, stating that they have a good hydrophilicity.


2021 ◽  
Author(s):  
Dezhong Xu ◽  
Yanan Cheng ◽  
Shuai Wu ◽  
Qiuxia Zou ◽  
Ajoy Kanti Mondal ◽  
...  

Abstract In this work, the tunicate cellulose nanocrystal (tCNC) was extracted from tunicate by bleaching and acid hydrolysis. It was used as filler in the preparation of sodium alginate-based enteric capsule. The addition of tCNC with high aspect ratio (65) rendered the enteric capsule excellent physical properties. Compared with the control sample, when the addition of tCNC was 10% (wt), the water contact angle of the capsule was enhanced by 46.0%, the opacity was increased by 356.8%, the maximum tensile stress was increased by 142.6%, the modulus of elasticity was increased by 240.3%, and the elongation at break was increased by 133.8%. In the in vitro degradation experiments, the capsule hardly degraded in the gastric environment (pH 1.2), while in the intestinal environment (pH 6.8), the degradation became slower with the increase of tCNC content, which was consistent with the properties of enteric capsule. This research developed a new direction for the application of tCNC in the pharmaceutical material productions.


2020 ◽  
Vol 8 (3) ◽  
Author(s):  
Moataz Abdulhafez ◽  
Angela J. McComb ◽  
Mostafa Bedewy

Abstract The growth of laser-induced nanocarbons, referred to here as laser-induced nanocarbon (LINC) for short, directly on polymeric surfaces is a promising route toward surface engineering of commercial polymers. This paper aims to demonstrate how this new approach can enable achieving varied surface properties based on tuning the nanostructured morphology of the formed graphitic material on commercial polyimide (Kapton) films. We elucidate the effects of tuning laser processing parameters on the achieved nanoscale morphology and the resulting surface hydrophobicity or hydrophilicity. Our results show that by varying lasing power, rastering speed, laser spot size, and line-to-line gap sizes, a wide range of water contact angles are possible, i.e., from below 20 deg to above 110 deg. Combining water contact angle measurements from an optical tensiometer with LINC surface characterization using optical microscopy, electron microscopy, and Raman spectroscopy enables building the process–structur–property relationship. Our findings reveal that both the value of contact angle and the anisotropic wetting behavior of LINC on polyimide are dependent on their hierarchical surface nanostructure which ranges from isotropic nanoporous morphology to fibrous morphology. Results also show that increasing gap sizes lead to an increase in contact angles and thus an increase in the hydrophobicity of the surface. Hence, our work highlight the potential of this approach for manufacturing flexible devices with tailored surfaces.


2012 ◽  
Vol 583 ◽  
pp. 374-378
Author(s):  
Qi Long Liu ◽  
Hong Chen ◽  
Hai Yun Jiang ◽  
Ruo Mei Wu ◽  
Zhi Qing Yuan ◽  
...  

A simple, cheap and environmental double thin super-hydrophobic composite film was prepared on the surface of tinplate by a simple casting method. The contact angle and sliding angle were measured by an optical contact angle meter. And the major factors that influenced the super-hydrophobic effect of the composite film were studied in our work. The results showed that when the melting temperature was 120°C, the weight radio of PP and PP-g-MAH was 1:4, the drying time was 24h, the dosage of ethanol was 0.4ml, the composite film showed a satisfactory super-hydrophobicity and its water contact angles reached a maximum value of 156.6° while the sliding angle reached a minimum value of 2°. Because of anti-oxidation, moisture-proof and anticorrosion performance of super-hydrophobic tinplate, it has potential practical applications in packaging material engineering.


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