scholarly journals WATER REPELLENT BREATHABLE PET/WOOL FABRIC VIA PLASMA POLYMERISATION TECHNOLOGY

2021 ◽  
Vol 2021 ◽  
pp. 74-80
Author(s):  
A. Haji ◽  
M. Khajeh Mehrizi ◽  
M. Ali Tavanai ◽  
M. Gohari

Water-repellent textiles are usually prepared by application of hydrophobic polymers such as fluorocarbons on fabrics using padding or spraying methods followed by drying and curing steps. These procedures impart hydrophobicity to the fabric, but harm the physical and handle properties of the fabric. In this study, low-pressure plasma was employed for the polymerization of 1H,1H,2H,2H-Perfluorooctyl acrylate on PET/Wool fabric for obtaining water-repellent properties with minimum effect on other desirable properties. To compare the results with the conventional industrial processes, a sample was treated with a commercial water-repellent agent using pad-dry-cure method. The water contact angle, bending length, tensile strength, air permeability, and surface morphology of the samples were compared. The plasma-treated sample showed similar water contact angle and higher fastness properties compared with the sample prepared by the conventional method. The tensile strength of the samples was similar, while the air permeability of the plasmatreated sample was higher and the coating was more uniform compared with the sample prepared by the paddry- cure method.

2018 ◽  
Vol 89 (6) ◽  
pp. 1013-1026 ◽  
Author(s):  
Rongrong Yu ◽  
Mingwei Tian ◽  
Lijun Qu ◽  
Shifeng Zhu ◽  
Jianhua Ran ◽  
...  

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.


2017 ◽  
Vol 7 ◽  
pp. 184798041770279 ◽  
Author(s):  
Baojiang Liu ◽  
Taizhou Tian ◽  
Jinlong Yao ◽  
Changgen Huang ◽  
Wenjun Tang ◽  
...  

A robust superhydrophobic organosilica sol-gel-based coating on a cotton fabric substrate was successfully fabricated via a cost-effective one-step method. The coating was prepared by modification of silica nanoparticles with siloxane having long alkyl chain that allow to reduce surface energy. The coating on cotton fabric exhibited water contact angle of 151.6°. The surface morphology was evaluated by scanning electron microscopy, and surface chemical composition was measured with X-ray photoelectron spectroscopy. Results showed the enhanced superhydrophobicity that was attributed to the synergistic effect of roughness created by the random distribution of silica nanoparticles and the low surface energy imparted of long-chain alkane siloxane. In addition, the coating also showed excellent durability against washing treatments. Even after washed for 30 times, the specimen still had a water contact angle of 130°, indicating an obvious water-repellent property. With this outstanding property, the robust superhydrophobic coating exhibited a prospective application in textiles and plastics.


2008 ◽  
Vol 3 (4) ◽  
pp. 155892500800300 ◽  
Author(s):  
Karthik Ramaratnam ◽  
Swaminatha K. Iyer ◽  
Mark K. Kinnan ◽  
George Chumanov ◽  
Phillip J. Brown ◽  
...  

It is well established that the water wettability of materials is governed by both the chemical composition and the geometrical microstructure of the surface.1 Traditional textile wet processing treatments do indeed rely fundamentally upon complete wetting out of a textile structure to achieve satisfactory performance.2 However, the complexities introduced through the heterogeneous nature of the fiber surfaces, the nature of the fiber composition and the actual construction of the textile material create difficulties in attempting to predict the exact wettability of a particular textile material. For many applications the ability of a finished fabric to exhibit water repellency (in other words low wettability) is essential2 and potential applications of highly water repellent textile materials include rainwear, upholstery, protective clothing, sportswear, and automobile interior fabrics. Recent research indicates that such applications may benefit from a new generation of water repellent materials that make use of the “lotus effect” to provide ultrahydrophobic textile materials.3,4 Ultrahydrophobic surfaces are typically termed as the surfaces that show a water contact angle greater than 150°C with very low contact angle hysteresis.4 In the case of textile materials, the level of hydrophobicity is often determined by measuring the static water contact angle only, since it is difficult to measure the contact angle hysteresis on a textile fabric because of the high levels of roughness inherent in textile structures.


Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5407
Author(s):  
Hyeju Kang ◽  
Sukpyo Kang ◽  
Byoungky Lee

In this study, the compressive strength and water contact angle of mortar specimens prepared by mixing two types of water repellent with ordinary Portland cement (OPC) and rapid-hardening cement mortar were measured before and after surface abrasion. In addition, the hydration products and chemical bonding of cement mortar with the repellents were examined using X-ray diffraction (XRD), thermogravimetry-differential thermal analysis (TG-DTA), and Fourier-transform infrared spectroscopy (FT-IR) to evaluate the performance of these cement mortar mixtures as repair materials. We found that the fast-hardening cement mortar mixture containing the oligomer water repellent showed the best performance with a high compressive strength and large water contact angle. With the oligomer water repellent, the rapid-hardening cement mortar mixture showed contact angles of 131° and 126° even after a 2 mm abrasion, thereby confirming that the water repellent secured hydrophobicity through strong bonding with the entire cement mortar as well as its surface. The compressive strengths were found to be 34.5 MPa at 3 h and 54.8 MPa at 28 days, confirming that hydration occurred well despite the addition of water repellent.


2018 ◽  
Vol 36 (2) ◽  
pp. 127-153 ◽  
Author(s):  
Ahmed Bahgat Radwan ◽  
Aboubakr M. Abdullah ◽  
Nasser A. Alnuaimi

AbstractExtreme water-repellent (superhydrophobic) coatings with water contact angle higher than 150° have caught the attention of corrosion researchers in the last decade as they can be used to protect metals and alloys against corrosion. The latter is a serious problem, as it can threaten human lives in addition to its deleterious effects on the economy and environment. Superhydrophobic coatings (SHCs) can be achieved by lowering the surface energy of a certain coating through combining some of its surface features at the microscale and nanoscales. Although SHCs can be prepared using many different easy techniques, none, to the best of our knowledge, has been applied, so far, on an industrial scale for protection against corrosion of metals and alloys. The present work explains the different models of superhydrophobic surfaces (SHSs) and reviews their fabrication and processing methods with a focus on the recent advances in the corrosion protection of the SHC.


Author(s):  
Mamoni Probha Borah and Binita Baishya Kalita

A novel approach was attempted for the functionalization of eri and its union fabrics with polymers for water repellency finishes. For the study, eri fabric was prepared with plain weave structure using 1/140s and 2/140s (warp and weft directions) and 2/140s of eri and 1/56s of wool yarn for the union fabric in both the warp and weft directions. For surface enrichment, silicone polymer was applied by the pad-dry-cure method. The untreated and treated fabric was evaluated for its hydrophobicity like the water contact angle and spray test, air permeability and physio-mechanical properties viz., counts, GSM, thickness, bending length, crease recovery, tensile strength and elongation were assessed. Analytical tests like UPF, whiteness, brightness, yellowness index for surface appearance was evaluated and SEM was performed. The marginal enhancement in bending length was observed in treated eri silk and union fabrics in both directions. The properties like thickness, brightness, yellowness, increased after application of silicone polymers, while crease recovery decreased. Noticeable enhancement of water contact angle was observed in eri silk and union fabric after adding silicone polymer and UPF was found to be excellent. There was no structural damage observed in all treated samples which are cleared from the Scanning Electron Microscope view. Application of silicone polymer on eri silk and its union fabrics improved the hydrophobic characteristic. The UPF protection properties were evaluated on both fabrics and recorded excellent UPF. In this study, the functional properties on eri silk and union fabrics were achieved successfully for functional clothing and textiles


2020 ◽  
Vol 91 (1-2) ◽  
pp. 40-50
Author(s):  
Md Ashikur Rahman ◽  
Changsang Yun ◽  
Chung Hee Park

Enzymatic hydrolysis is a common finishing method for cellulosic materials, to improve fabric softness, appearance, and surface properties. However, its potential to trigger superhydrophobicity has not been studied in depth. In this study, a superhydrophobic cellulose fabric was fabricated in two steps. Micro-/nano-hierarchical roughness on the fabric surface was achieved by cellulase from Aspergillus niger, through enzymatic hydrolysis. Subsequently, hydrophobization was carried out by a dip coating method, using polydimethylsiloxane (PDMS). Enzyme concentration and treatment temperature were varied to find the values that provided the greatest superhydrophobicity. As enzyme concentration and temperature increased, the nano-scale roughness increased, along with weight reduction. The degree of crystallinity and reduction in tensile strength were also increased with weight loss via enzyme hydrolysis. As air pockets were formed by micro-/nano-structures on the fiber surface, the water contact angle increased and the shedding angle tended to decrease. The sample treated with 5 g/l enzyme at 60 ℃ for 60 min and coated with PDMS 1 wt.% coating solution had the greatest superhydrophobicity, with a water contact angle of 162° and a shedding angle of 7.0°. The weight loss and reduction in tensile strength of the developed superhydrophobic fabrics were 2.9% and 39.0%, respectively. This approach reduces the necessity for an additional process to introduce nano-scale roughness, and it has the potential to produce superhydrophobic cellulosic biomass for outdoor clothing.


2018 ◽  
Vol 18 (4) ◽  
pp. 587 ◽  
Author(s):  
Alfa Akustia Widati ◽  
Nuryono Nuryono ◽  
Dessy Puspa Aryanti ◽  
Madjid Arie Wibowo ◽  
Eko Sri Kunarti ◽  
...  

In this study water repellent layered glass has been prepared by coating silica (SiO2) combined with a hydrophobic silane compound. SiO2 was extracted from rice hull ash and two silane compounds, namely hexadecyltrimethoxysilane (HDTMS) and trimethylchlorosilane (TMCS) were used. Coating was performed through two deposition techniques, i.e. one step (mono-layer) and layer by layer (LBL, multi-layer). The effect of silane to SiO2 mole ratio, silane type and layer number on the glass characters was evaluated. Characterization included hydrophobicity, transparency, surface roughness and stability of coating. Results showed that increasing the mole ratio of silane to SiO2 and the layer number increased the hydrophobicity of the glass surface. The optimum mole ratio was 5:1 and the significant increase of contact angle occurred at lower mole ratio, but the stability tends to be increased at higher mole ratio. For HDTMS-SiO2 layer, the technique of LBL technique produced a coating with higher hydrophobicity and transparency than single-stage one. The LBL technique produced the highest water contact angle of 103.7° with transmittance of 96%, while for TMCS-SiO2 layer the one stage technique produced hydrophobic layer with higher water contact angle of 108.0° and transparency about 94.52%. The prepared hydrophobic glasses were relatively stable in polar and non-polar solvents, but unstable to ambient conditions.


2019 ◽  
Vol 90 (2) ◽  
pp. 166-178 ◽  
Author(s):  
Ji Eun Song ◽  
Artur Cavaco-Paulo ◽  
Carla Silva ◽  
Hye Rim Kim

The present study aimed to improve the properties of bacterial cellulose nonwoven fabrics by physical entrapment of lauryl gallate oligomers. The lauryl gallate oligomerization process was conducted by laccase-mediated oligomerization. Lauryl gallate was chemically confirmed by matrix-assisted laser desorption/ionization with time-of-flight analyses. The oligomerization conditions were controlled considering the surface properties (water contact angle, surface energy, and water absorption time) of bacterial cellulose nonwoven fabrics. The controlled oligomerization conditions were 160 U/mL of laccase and 20 mM lauryl gallate. After bacterial cellulose was treated by the physical entrapment of lauryl gallate oligomers, X-ray photoelectron spectroscopy analysis showed that the N1 atomic composition (%) of bacterial cellulose increased from 0.78% to 4.32%. This indicates that the lauryl gallate oligomer molecules were introduced into the bacterial cellulose nanofiber structure. In addition, the water contact angle was measured after washing the bacterial cellulose nonwoven fabric treated by the physical entrapment of lauryl gallate oligomers for 180 minutes, and it was found to maintain a water contact angle of 88°. The durability of bacterial cellulose nonwoven fabric treated by the physical entrapment of lauryl gallate oligomers was confirmed by measuring the tensile strength after wetting and dimensional stability. As a result, the tensile strength after wetting was about five times higher and the dimensional stability was three times higher than that of untreated bacterial cellulose nonwoven fabric.


Sign in / Sign up

Export Citation Format

Share Document