Abstract:Electrospun fabrics, prepared from 5, 7 and 10%w/v were Poly(vinyl alcohol) (PVA) solutions successfully prepared. The electrospinning condition was 15 kV, distance 15 cm, flow rate of 1 ml/hr and spinning time of 5 hours. Physical properties of electrospun PVA fabrics were analysed by SEM, FE-SEM and contact angle measurement.The contact angle of the electrospun PVA fabrics was 54.5°, characterizing the hydrophilicity of the fabrics. Hydrophobic properties of the electrospun PVA fabrics were improved by pla… Show more
“…A sharp corona discharge electrode was used to treat mats of hydrophobic PLLA, which became hydrophilic due to the presence of carboxyl groups on the surface produced by the treatment with N 2 followed by air exposure [96]. Hydrophobisation by plasma can be achieved with reactive gases such as CF 4 and SF 6 to introduce low surface energy fluorine-containing groups on the surface, leading to superhydrophobicity of hydrophilic (PVA [97]) or hydrophobic (CTA [98], PCL [85]) polymers. Figure 9. Effect of processing parameters on the hydrophilisation of electrospun mats: (a) Contact angle results for PCL mats treated with different gases, plasma power and time[84]. Reproduced with permission from Wiley-VCH, Germany; (b) Influence of plasma power on the contact angle of PVDF mats[101].…”
Section: Surface Modification Methodsmentioning
confidence: 99%
“…A sharp corona discharge electrode was used to treat mats of hydrophobic PLLA, which became hydrophilic due to the presence of carboxyl groups on the surface produced by the treatment with N 2 followed by air exposure [96]. Hydrophobisation by plasma can be achieved with reactive gases such as CF 4 and SF 6 to introduce low surface energy fluorinecontaining groups on the surface, leading to superhydrophobicity of hydrophilic (PVA [97]) or hydrophobic (CTA [98], PCL [85]) polymers.…”
Electrospun mats have many possible applications in which it is important to control their interaction with water: when used as separation membranes, superhydrophobic mats can remove oil from water, whereas when used as scaffolds for tissue engineering, hydrophilic mats present better cell affinity. Frequently, however, the surface properties of the polymer fibers that compose the mat need to be modified and tuned. This review covers the main surface modification techniques used to change the water wettability of mats produced by electrospinning. Some basic aspects of the electrospinning process and wetting theories are presented as a starting point for the discussion, highlighting the common wetting switching mechanism found in highly porous structures like electrospun mats. The surface modification techniques are then classified as post-treatments or one-step modification during electrospinning. The fundamental aspects of each technique are followed by a discussion emphasizing their technical advantages and drawbacks.
“…A sharp corona discharge electrode was used to treat mats of hydrophobic PLLA, which became hydrophilic due to the presence of carboxyl groups on the surface produced by the treatment with N 2 followed by air exposure [96]. Hydrophobisation by plasma can be achieved with reactive gases such as CF 4 and SF 6 to introduce low surface energy fluorine-containing groups on the surface, leading to superhydrophobicity of hydrophilic (PVA [97]) or hydrophobic (CTA [98], PCL [85]) polymers. Figure 9. Effect of processing parameters on the hydrophilisation of electrospun mats: (a) Contact angle results for PCL mats treated with different gases, plasma power and time[84]. Reproduced with permission from Wiley-VCH, Germany; (b) Influence of plasma power on the contact angle of PVDF mats[101].…”
Section: Surface Modification Methodsmentioning
confidence: 99%
“…A sharp corona discharge electrode was used to treat mats of hydrophobic PLLA, which became hydrophilic due to the presence of carboxyl groups on the surface produced by the treatment with N 2 followed by air exposure [96]. Hydrophobisation by plasma can be achieved with reactive gases such as CF 4 and SF 6 to introduce low surface energy fluorinecontaining groups on the surface, leading to superhydrophobicity of hydrophilic (PVA [97]) or hydrophobic (CTA [98], PCL [85]) polymers.…”
Electrospun mats have many possible applications in which it is important to control their interaction with water: when used as separation membranes, superhydrophobic mats can remove oil from water, whereas when used as scaffolds for tissue engineering, hydrophilic mats present better cell affinity. Frequently, however, the surface properties of the polymer fibers that compose the mat need to be modified and tuned. This review covers the main surface modification techniques used to change the water wettability of mats produced by electrospinning. Some basic aspects of the electrospinning process and wetting theories are presented as a starting point for the discussion, highlighting the common wetting switching mechanism found in highly porous structures like electrospun mats. The surface modification techniques are then classified as post-treatments or one-step modification during electrospinning. The fundamental aspects of each technique are followed by a discussion emphasizing their technical advantages and drawbacks.
“…Contact angle measurements were taken on hydrated and dehydrated BLF gel samples to quantify the hydrophobicity of the polymer matrix and the biphasic system. The contact angles for the hydrated PVA gels were within the typical range for PVA which is between 30 and 60 degrees based on M w and PVA concentration within solution 36. Hydrophobicity has a direct relationship with the contact angle, namely a higher contact angle indicates higher hydrophobicity of the material.…”
A novel material design was developed by functionalizing polyvinyl alcohol hydrogel with an organic low-friction boundary lubricant (molar ratios of 0.2, 0.5, and 1.0 moles of lauroyl chloride). The hydrogels were fabricated using two different techniques. First, the boundary lubricant was initially functionalized to the polymer, then the hydrogels were created by physically crosslinking the reacted polymer. Second, hydrogels were initially created by crosslinking pure polyvinyl alcohol, with the functionalization reaction performed on the fully formed gel. After the reaction, Fourier transform infrared spectroscopy and attenuated total reflectance spectra revealed a clear ester peak, the diminishment of the alcohol peak, and the amplification of the alkyl peaks, which confirmed attachment of the hydrocarbon chains to the polymer. Additional chemical characterization occurred through elemental analysis where an average increase of 22% carbon and 40% hydrogen provided further confirmation of attachment. Physical characterization of the boundary lubricant functionalized hydrogels was performed by water content and contact angle measurements. Water content dependency showed that method 1 had a direct relationship with boundary lubricant concentration, and method 2 displayed an inverse relationship. The contact angle increased as boundary lubricant concentration increased for the pure matrix material for both processing methods, suggesting that the hydrocarbons produced surface properties that mimic natural cartilage, and contact behavior of the biphasic system was dependent on processing method. Friction tests demonstrated a significant decrease in friction coefficient, with a maximum decrease of 70% and a minimum decrease of 24% for boundary lubricant functionalized hydrogels compared with nonfunctionalized polyvinyl alcohol hydrogels.
“…The hydrophobicity of electrospun PVA fabrics can be achieved using SF6 plasma treatment. The application areas of these fabrics are biomaterial, filtration and medical devices 57 . Recently, hydrophobic textiles have been made by etching titanium dioxide-coated layer of the fabric with CF4 plasma treatment 58 .…”
Section: Characteristics Of Hydrophobicity and Lotus Effectmentioning
Nature has created excellent technologies around us, and as such, it is the chief mentor to humans on creativity and technology development. Nature uses fibre as a building block -natural structures like wood, bamboo, bone, muscle, etc. all have fibrous structure. Fibre spinning and weaving technologies are available in nature since time immemorial. Nature has also demonstrated sophisticated technologies useful in the development of technical textiles like functional surfaces, camouflage, structural colour, thermal insulation, dry-adhesion, etc. Thus, biomimicry can be an inspiration to develop innovative textiles. This article reviews some of the important technologies of nature relating to textiles.
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