Facile fabrication of superhydrophobic cotton fabric from stearyl methacrylate modified polysiloxane/silica nanocomposite

The stearyl methacrylate modified polysiloxane/nanocomposite was synthesized by graft copolymerization between stearyl methacrylate modified polysiloxane with pendent epoxy groups and amino-functionalized nano silica. Then it was utilized to fabricate the superhydrophobic cotton fabric by one-step method. The structures, chemical compositions, thermal properties, surface morphology and wettability were characterized by Fourier Transform Infrared Spectrum (FT-IR), X-ray photoelectron spectroscopy (XPS), Thermo-gravimetric analyzer (TGA), Scanning electron microscopy (SEM) and Static contact angle analyzer. Results showed that a hydrophobic polysiloxane film and many nano-scaled tubercles were coated on the surface of the treated cotton fabrics plus their inherent microscaled roughness, which were the reasons why cotton fabric changed from hydrophilicity to hydrophobicity. In addition, with increase of the amount of nanocomposite, hydrophobicity of the treated cotton fabric would be enhanced; water contact angle of this fabric could attain 157°, which was higher than 141.5° reached by the fabric treated with stearyl methacrylate modified polysiloxane. The superhydrophobic cotton fabric also possessed favorable washing durability. On the other hand, its air permeability, color and softness would not be influenced instead.     

Robust Water-Repellent Treatment of Cotton Fabrics with Polysiloxane Modified via Thiol-Ene Click Reaction

A facile and inexpensive way to prepare self-crosslinkable poly(dimethylsiloxane) (PDMS) for superhydrophobic treatment of cotton fabrics is reported in the study. Through thiol-ene click reaction between mercaptopropyltrimethoxysilane (MPTMOS) and vinyl-containing poly(dimethylsiloxane) (VPDMS), PDMS-g-TMOS can be simply and quickly synthesized. The trimethoxysilane group of PDMS-g-TMOS can react with hydroxyl group on cotton fabric and other -Si(OCH₃)₃ groups. The synthesized polysiloxane (PDMS-g-TMOS) was identified by FT-IR and ¹H-NMR. The morphology of the treated cotton fabric was observed by SEM and XPS was used to analyze the elemental composition on the surface of cotton fabric. The analysis results indicated that the surface was fully covered with PDMS. Due to the low surface energy of PDMS and the rough surfaces of cotton fabric, the optimized water contact angle (WCA) and sliding angle were respectively 154°±0.4° and 14°±0.5°, indicating superhydrophobicity. Moreover, water spray test (AATCC Test Method 22-2010) was also applied to evaluate the water repellency of treated cotton fabric and a score of 90 was assigned according to AATCC Test Method 22-2010. The durability of treated cotton fabric was tested by 50 laundering cycles. The resultant WCA barely decreased and the score of water spray test dropped from 90 to 80, showing the reasonable wash durability.     

Parametric study of CF4-plasma on the hydrophobicity of polyester synthetic leather

Atmospheric pressure plasma (APP) technology has been proven to be an effective method for improving the hydrophobicity of fabric surface. While many researchers have worked on apparel fabrics, polyester and synthetic leather fabrics, popular in the luxury textile market, have been examined rarely. In this regard, this paper reports the effects of APP treatment using tetrafluoromethane (CF₄) as the polymerizing monomer on hydrophobicity of polyester synthetic leather. The polyester synthetic leather samples were treated under various parameters and hydrophobicity was found to be greatly enhanced under a certain range of treatment conditions. An optimization of the treatment parameters was conducted and the results showed that a hydrophobic surface with a contact angle of 106 ° was achieved, compared to the untreated sample’s 0 °.     

Synthesis,film morphology and performance of novel crosslinked polysiloxane with end-capped epoxy groups on cotton substrates

An epoxy group-terminated polyvinylmethylsiloxane (EPVMS) was firstly prepared via the cohydrolysis/condensation reaction of octamethylcyclotetrasiloxane (D₄), 2,4,6,8-Tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane (D₄V), and epoxy group-terminated polydimethylsiloxane (ETP) under a base catalyst. Then, the EPVMS was reacted with polymethylhydrosiloxane oligomer (PHMS) by hydrosilylation to develop novel crosslinked polysiloxane with end-capped epoxy groups (CLPS). The chemical structure and the thermal property of the as-prepared products were characterized by Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance spectra (¹H/¹³C NMR) and thermogravimetric analysis (TGA). Finally, the CLPS was applied as the finishing agent to treat the cotton fabrics. The film morphology and the surface properties were examined with scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), contact angle measurements, and other instruments. FT-IR and NMR results confirmed the structure of the resultants. The crosslinked polysiloxane CLPS showed better thermal stability than the uncrosslinked polysiloxane EPVMS. The CLPS film on cotton fabric surface seemed to be smooth compared to the control by SEM. However, owing to the crosslinked structure, the CLPS film on silicon-wafer was inhomogeneous and had a few weak or strong peaks. At 5 nm data scale and in 2×2 μm² scanning field, the root mean square roughness of CLPS film reached to 0.414 nm. XPS analysis further demonstrates that there was a CLPS film covered on the cotton surface. Hydrophobicity of the CLPS treated fabric was superior to that of the EPVMS treated one. Whiteness of the treated fabrics by CLPS and EPVMS did not change at all compared to the control. The softness of the two treated fabrics was both better than that of control and particularly the softness of the EPVMS treated fabrics was preferable. The CLPS treated fabric possessed good washing durability.     

A study of physical modification on grey cotton by laser irradiation

The surface morphology of the CO₂ laser treated grey cotton fabrics was studied which showed a characteristics sponge-like structure on cotton fibres after treating with CO₂ laser irradiation. The laser treatment parameters ranging from 100 to 150 pixel time and 40 to 70 dot per inch (dpi) were irradiated on the grey cotton fabrics directly and the degree of physical modifications, such as surface morphology, wettability and fabric strength, were changed accordingly with various laser treatment parameters. The surface morphology, wettability and tensile strength of cotton fibre treating with laser were evaluated using different instruments, such as Scanning Electron Microscope (SEM), contact angle meter and tensile strength machine. In spite of creating a sponge-like structure on fibre surface after treating with laser, the wettability of the samples was highly improved but the tensile strength was decreased.     

Superhydrophobic and Antibacterial Properties of Cotton Fabrics Treated with PVDF and nano-ZnO through Phase Inversion Process

Cotton fabrics exhibiting superhydrophobic and antibacterial properties were prepared through a non-solvent induced phase separation method using hydrophobic poly(vinylidene fluoride) (PVDF) and its hybrids with photocatalytic zinc oxide nanoparticles (nano-ZnO) as surface modifying agents for cotton fabric. The effects of coagulating medium and temperature on microstructural morphology and surface hydrophobictity of the cotton fabrics were investigated by FE-SEM observation and contact angle measurement. Superhydrophobic cotton fabrics exhibiting water contact angle higher than 150 ° could be obtained by coating the fabrics with solutions of PVDF and nano-ZnO followed by coagulation in ethanol as non-solvent. This phenomenon is considered to be originated from both chemically hydrophobic PVDF layer and physical micro- and nano-bumps formed on the surface of cotton fabric, which are essential requirements for Lotus effect. Moreover, antibacterial properties could be synergistically obtained by utilizing photocatalytic effect of nano-ZnO.     

Surfactant effects on application of a hydrophobic, fluoropolymer coating to cotton by admicellar polymerization

Various methods have been used previously to impart hydrophobicity to cotton. In this study, thin co-polymer films of trifluoroethyl acrylate (TFEA) and octafluoro pentyl methacrylate (OFPM) were formed on cotton using individual fluorosurfactants and surfactant mixtures through the process of admicellar polymerization. Efficacy of 6 different fluorosurfactant systems and process conditions including surfactant type, concentration, adsorption/adsolubilization time, polymerization time, and monomer concentration have been investigated in order to obtain hydrophobic coatings on woven cotton fabric. Adsolubilization times as short as 2 h and polymerization times as short as 1 h yielded satisfactory performance. Characterization of the hydrophobic polymer films obtained included static contact angles, SEM imaging, elemental analysis and XPS analysis. Treated fabrics exhibited good water repellency for several surfactants and surfactant mixtures with initial supernatant monomer concentrations of 4 mM. Surfactant mixtures were able to outperform the separate individual species in admicellar polymerization.     

Preparation of electroconductive,magnetic, antibacterial,and ultraviolet-blocking cotton fabric using reduced graphene oxide nanosheets and magnetite nanoparticles

The main goal of present study was the fabrication of cotton fabric with special functions, including electrical conductivity, magnetic, antibacterial, and ultraviolet (UV) blocking. In this regard, the cotton fabric was primarily coated with graphene oxide and then reduction of graphene oxide and synthesis of magnetite nanoparticles accomplished in one step. The alkaline hydrolysis of magnetite precursors and reduction of graphene oxide was simultaneously performed using sodium hydroxide to produce reduced graphene oxide/Fe₃O₄ nanocomposite on the fabric surface. The prepared cotton fabrics were characterized with field emission scanning electron microscope (FE-SEM), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS). The treated fabrics with reduced graphene oxide/Fe₃O₄ nanocomposite displayed a low electrical resistivity i.e. 80 kΩ/sq. Furthermore, the coated fabrics showed reasonable magnetic properties due to the presence of magnetite nanoparticles on the surface of cotton fabrics. Moreover, this process imparted proper antibacterial properties and UV blocking activity to cotton samples.     

Influence of oxygen plasma pre-treatment on the water repellency of cotton fibers coated with perfluoroalkyl-functionalized polysilsesquioxane

Oxygen plasma pre-treatment was applied to cotton fabric with the aim of improving the water repellency performance of an inorganic-organic hybrid sol-gel perfluoroalkyl-functionalized polysilsesquioxane coating. Cotton fabric was pre-treated with low-pressure oxygen plasma for different treatment times and operating powers. Afterward, 1H,1H,2H,2H-perfluorooctyltriethoxysilane (SiF) was applied to the cotton fabric samples using the pad-dry-cure method. The surfaces of the untreated and modified cotton fibers were characterised using Fourier transform infrared spectroscopy, Xray photoelectron spectroscopy, scanning electron microscopy, and atomic force microscopy. The water repellency of the SiF-coated fabric samples was evaluated using static and sliding contact angle measurements with water. The results show that the plasma treatment with the shortest treatment time (10 s) and the lowest operating current (0.3 A) increased the atomic oxygen/carbon ratio of the cotton fiber surface from 0.6 to 0.8 and induced the formation of a nano-sized grainy surface. Increasing the plasma treatment time and/or operating current did not intensify the surface changes of the cotton fibers. Such saturation effects were explained by the large influence of reactive oxygen atoms during the plasma treatment. The measured static water contact angles on the surface of the untreated and plasma pre-treated and SiF-coated cotton fabrics showed that the oxygen plasma pre-treatment enabled the increase of the water contact angle from 135° to ≈150°, regardless of the applied plasma treatment time and discharge power. This improvement in the hydrophobicity of the SiF coating was followed by a decrease in the sliding angle of water droplets by more than 10° compared to the plasma untreated and SiF-coated sample characterized by a water sliding angle of 45°. Additionally, measurements of the water sliding angle revealed that the increase of the static contact angle from 149° to 150° corresponded to a drop of the water sliding angle from 33 to 24°, which suggests that the plasma pre-treatment of 20 s at an operating current of 0.3 A produced the best water-repellent performance of the SiF-coated cotton fabric.     

Highly Durable and Robust Superhydrophobic/Superoleophilic Cotton Fabric with Well-designed Roughness for Oil/Water Separation

Herein we report a simple and reproducible method for fabricating highly durable and robust superhydrophobic and superoleophilic cotton fabrics via simultaneous radiation-induced graft polymerization of glycidyl methacrylate and subsequent chemical modifications with aminopropyltriethoxysilane and hexamethyldisilazane. The chemical structure and the surface topography of the pristine and the modified cotton fabrics were investigated in detail by ATR-FTIR, XPS, and ²⁹Si NMR, and a grafting layer was successfully immobilized onto the surface of the cotton fabric by forming covalent bonds. Multi-dimensional surface roughness was created by combining micro-sized fibers of the cotton fabric, nanoscaled protuberances of the grafting chain, and molecular level spherical projection points of silicon methyl. The superhydrophobic cotton fabric exhibited long-term stability, ultra-high durability and robustness, and maintained its properties even after 25 wash cycles. The fabric also showed excellent water repellency with a water contact angle of 153 ° and a high efficiency of oil/water separation (98 %). The superhydrophobic/superoleophilic cotton fabric developed in the present work exhibits important potential applications in superhydrophobic textiles and oil/water separation.     

Application of silver nanoparticles to cotton fabric as an antibacterial textile finish

A novel nano-silver colloidal solution was prepared in one step by mixing AgNO₃ aqueous solution and an amino-terminated hyperbranched polymer (HBP-NH₂) aqueous solution under vigorous stirring at room temperature. All results of Dynamic Light Scattering (DLS), Transmission Electron Microscopy (TEM) and UV/Visible Absorption Spectrophotometry indicated that silver nanoparticles had been formed in colloidal solution. Cotton fabric was treated with nano-silver colloid by an impregnation method to provide the cotton fabric with antibacterial properties. The whiteness, silver content, antibacterial activity and washing durability of the silver-treated fabrics were determined. The results indicated that the silver-treated cotton fabric showed 99.01 % bacterial reduction of Staphylococcus aureus and 99.26 % bacterial reduction of Escherichia coli while the silver content on cotton was about 88 mg/kg. The antimicrobial activity of the silver-treated cotton fabric was maintained at over 98.77 % reduction level even after being exposed to 20 consecutive home laundering conditions. In addition, the results of scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) confirmed that silver nanoparticles have been fixed and well dispersed on cotton fabrics’ surface and the major state of the silver presented on the surface was Ag⁰.     

N-halamine-bonded cotton fabric with antimicrobial and easy-care properties

N-halamine precursor 2,2,6,6-tetramethyl piperidinol (TMP), a hindered amine light stabilizer, was bonded onto cotton fabric by using 1,2,3,4-butanetetracarboxylic acid (BTCA) as a crosslinking agent. A variety of treating conditions including TMP concentration, curing temperature and time, and catalyst were studied. The treated fabrics were characterized using FTIR spectra and scanning electron microscope (SEM). The cotton fabric treated with TMP precursor could be rendered biocidal upon exposure to dilute household bleach. The chlorinated cotton swatches showed great efficacy and inactivated 100 % of Staphylococcus aureus with 7.1 log reduction with 5 min of contact and 83.25 % of E. coli O157:H7 at 10 min of contact. In addition, the wrinkle recovery angle of the treated cotton fabrics increased from 229 ° of untreated cotton fabrics to 253 °. This study provided a practical finishing process to produce cotton fabrics with easy care and antibacterial functionalities at the same time.     

Fabric objective measurement of the plasma-treated cotton fabric subjected to wrinkle-resistant finishing with BTCA and TiO<Subscript>2</Subscript> system

Handle is an important factor when designing the end-uses of fabric as it is also a critical factor for purchasing decision. In the present study, the Kawabata Evaluation System for Fabrics (KES-F) was used for measuring the fabric handle of BTCA-TiO₂ treated cotton fabric with or without plasma pre-treatment. The results revealed that the BTCA-TiO₂ treated cotton fabrics without plasma pre-treatment had a negative effect on tensile, shearing, compressional, and surface properties while the bending properties were improved. On the other hand, the plasma pre-treatment improved the tensile and compressional properties, but not the bending, shearing, and surface properties.     

Improving thermal conductivity of cotton fabrics using composite coatings containing graphene, multiwall carbon nanotube or boron nitride fine particles

Graphene, multi-wall carbon nanotube (MWCNT) and fine boron nitride (BN) particles were separately applied with a resin onto a cotton fabric, and the effect of the thin composite coatings on the thermal conductive property, air permeability, wettability and color appearance of the cotton fabric was examined. The existence of the fillers within the coating layer increased the thermal conductivity of the coated cotton fabric. At the same coating content, the increase in fabric thermal conductivity was in the order of graphene > BN > MWCNT, ranging from 132 % to 842 % (based on pure cotton fabric). The coating led to 73 %, 69 % and 64 % reduction in air permeability when it respectively contained 50.0 wt% graphene, BN and MWCNTs. The graphene and MWCNT treated fabrics had a black appearance, but the coating had almost no influence on the fabric hydrophilicity. The BN coating made cotton fabric surface hydrophobic, with little change in fabric color.     

Multifunctional,Hydrophobic and Flame-retarded Cotton Fabrics Modified with Liner Piperzine/Phosphorous/Polysiloxane Copolymer

α,ω-di[(4-butoxy-piperazin-1-yl)-phosphinic acid methyl ether]-terminated linear polysiloxane (PNPDMS) was synthesized and utilized as the flame retardant and hydrophobing agent. The flame retardance and thermal decomposition behaviors of cotton fabrics were systematically estimated by limiting oxygen index (LOI), thermogravimetric analysis and vertical burning test, respectively. It was found that the LOI of cotton fabric treated with PNPDMS enhanced to 29.82 % compared with cotton fabric without treatment, whose LOI was only 18.00 %. The treated cotton fabric showed a shorter char length, a shorter After-flame time, and no After-glow time as revealed in vertical burning test. The mechanical property in treated cotton fabric was slightly decrease. Furthermore, the grade of water repellency of treated cotton fabric reached to 90 and water contact angle (WCA) increased to 141.90° compared with cotton fabric without treatment whose WCA was 62.80°. The result showed that the cotton fabric treated with PNPDMS exhibited excellent flame retardance and hydrophobic properties.     

Surface Modification of Wool Fabric with POSS® Nanomaterial

Wool fabrics, without any surface treatment, can undergo undesirable and irreversible structural changes of wool fiber during washing under heat and mechanical agitation, leading to high shrinkage of wool garments. The traditional method based on polyamide resin can prevent felting and/or shrinkage of wool textiles, but adversely affect the surface hydrophobicity. In the present study, a treatment solution was developed based on TriSilanolIsooctyl POSS® and 3- mercaptopropyl trimethoxysilane, which created wool surface with increased hydrophobicity and highly resistant to shrinkage or felting, as measured after 3×5A wash cycles (equivalent to 24 domestic washes). After the treatment, the wool fabric appeared to be superhydrophobic with a water contact angle of above 150°, compared to the untreated fabric. The treatment has marginal effect on mechanical performance as observed in tensile properties. Scanning electron microscopic images revealed a coating of POSS® on the wool surface. The dyeing of untreated and treated fabrics appeared to be uniform to the naked eye, though spectrophotometric analysis indicated a difference in the extent of dyeing performance. This research showed that POSS®-based treatment is a potentially effective approach for developing shrink-resistant wool textiles with enhanced surface hydrophobicity, in contrast to traditional chlorine/polyamide resin treatment.     

Structural characterization of LbL assembled multilayers by using different polyelectrolytes on cotton fabrics

An alternative approach to application of chitosan based on layer by layer (LbL) assembled technique is studied in this paper. For this aim, chitosan (CHT) was used as a bio-based cationic polyelectrolyte and pentasodium tripolyphosphate (TPP) and poly(sodium 4-styrene sulfonate) (PSS) were selected as anionic polyelectrolyte. TPP/CHT and PSS/CHT based bilayers were fabricated on the cationized woven cotton fabrics via layer-by-layer self-assembly technique. The characterization of coatings on the fabric surface in terms of surface appearance, atomal content, and chemical bondings were made in detail through SEM, XPS, and FTIR-ATR analysis. Also, the antibacterial activity, air permeability, and water contact angle were measured. Surface analyses demonstrate the interaction between TPP, PSS and chitosan separately. XPS spectra also showed the existence of LbL deposition over cotton substrates in terms of both elemental composition and the presence of different types of bondings on the fabric surface. The antibacterial activity analysis revealed that the modified cotton fabric with the addition of CHT/TPP and CHT/PSS bilayers could increase the degree of inhibition on K. pneumanie and S. aureus bacteria.     

Synthesis of cationic core-shell fluorine-containing polyacrylate soap-free latex and its application on cotton substrate

Fluorinated polyacrylate latexes are preferably potential materials for use in the textile finishing due to their special surface property and especially economical, low-toxic characteristics compared to fluorinated polyacrylate solutions. A novel cationic fluorine-containing polyacrylate soap-free latex (CFMBD) with core-shell structure was accordingly developed by co-polymerizing dodecafluoroheptyl methacrylate (DFMA), methyl methacrylate (MMA), butyl acrylate (BA), and dimethylaminoethyl methacrylate (DM) using a cationic reactive emulsifier, maleic acid double ester-octadecyl poly(ethyleneoxy)₂₀ ether-ethylene trimethyl ammonium chloride (R303). Then CFMBD was utilized to treat the cotton fabric. Results showed that the as-prepared latex had due structure and its particles had uniform spherical core-shell structure with an average diameter of 125 nm. The core-shell CFMBD latex film thus had two T _g and its thermal property was improved due to the introduction of DFMA. CFMBD could form a smooth resin film on the treated fabric/fiber surface under FESEM observation. XPS analysis indicated the fluoroalkyl groups had the tendency to enrich at the film-air interface. Hydrophobicity of the CFMBD treated fabric was slightly superior to that of the fabric treated by general emulsion but their oleophobicity was identical. Contact angles of water and diiodomethane on the CFMBD treated fabric surface could attain 133.5 ° and 105.5 °, respectively. However, washing durability of the treated fabric by CFMBD showed improvement compared to the general emulsion. In addition, CFMBD didn’t influence whiteness of the treated fabric but would make it slightly stiff at high doses.     

Water and oil-repellent coatings of perfluoro-polyacrylate resins on cotton fibers: UV curing in comparison with thermal polymerization

UV curing of perfluoro-alkyl-polyacrylate resins able to impart water as well as oil-repellency to cotton fabrics was studied in comparison with conventional thermal polymerization. The process was assessed through weight gain and gel content measurements while the properties conferred to cotton fabrics were determined in terms of water and oil contact angles, moisture adsorption, and water vapor permeability. The polymerization yields were of the same order (>80 %) of those obtained with thermal curing as well as the high contact angles with water (>127°) and oil (>118°) even at low resin add-on (3 %). UV cured resins yielded oil contact angles mostly higher than 120° denoting super oil-repellent surfaces. Moreover the water and oil-repellency was adequately maintained after washing. The moisture adsorption of finished fabrics was lower than that of untreated cotton, but slightly higher for UV cured than thermally treated fabrics. Water vapor transmission rate showed that the finish treatment, thermal as well as by UV curing, does not reduce the breathability of the original cotton. DSC analysis demonstrated that the fiber pyrolysis is affected by the polymer add-on, while FTIR-ATR spectra of all finished fabrics showed typical peaks of ester and C-F groups. XPS analysis showed small differences between thermal and UV curing coatings with each resin, while coatings with the lowest percentage of fluorine groups did not affect the water and oil-repellency.     

Modification of cotton fabric by mussel-inspired for oil/water separation

An oil/water separation cotton fabric with high separation efficiency has been successfully developed by combining mussel-inspired one-step copolymerization approach and Michael addition reaction. The cotton fabric was first coated with the adhesive polydopamine (PDA) film by simple immersion in an aqueous solution of dopamine at pH of 8.5. Then n-dodecyl mercaptan (NDM) was conjugated with PDA film through Michael addition reaction at ambient temperature. The chemical structure, surface topography, and surface wettability of the fabric were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy, and contact angle experiments, respectively. The results showed that as-prepared cotton fabric had highly hydrophobicity with the water contact angle of 145° and superoleophilicity with the oil contact angle of 0°. It exhibited desirable property of oil/water separation, and it had excellent potential to be used in practical applications and has created a new field for oil/water separation.