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[en] Highlights: • Multifunctional fabrics were fabricated via dip coating of polydimethylsiloxane, ZnO, and polydimethylsiloxane layers. • Samples exhibited excellent anti-wetting properties, good abrasion resistance, and durable laundering stability. • The fabrics displayed excellent UV-shielding ability due to the incorporation of ZnO particles. • The fabrics are superhydrophobic and self-cleaning, and can be used for oil-water separation. It remains a great challenge to prepare multi-functional fabrics using a low-cost and scalable method with fluorine-free materials. In this paper, we report a new procedure for producing fluorine-free super hydrophobic cotton fabrics, via a simple dip-coating process. Firstly, a polydimethylsiloxane (PDMS) adhesive layer is deposited onto the cotton substrate, followed by the subsequent deposition of ZnO nanoparticles to enhance the surface roughness through an oil bath process. Finally, a second PDMS dip-coating is applied to construct a multi-layered PDMS-ZnO-PDMS composite coating on the cotton fabrics. The multi-layer coated samples display superhydrophobic properties, with a water contact angle (CA) exceeding 160°. Additionally, the new [email protected] fabric exhibits excellent multi-functions, including UV-blocking, self-cleaning and oil-water separation. The prepared superhydrophobic fabric can withstand a large number of abrasion cycles and 20 cycles of accelerated washing without obvious decline in the water contact angle. This facile preparation method is of low-cost, environmentally friendly, and suitable for large-scale production of a series of specialty fabrics including sports clothing.
[en] After irradiating with a single dose of 50 Gy, ginger rhizomes were dipped into paraffin for coating, wrapped in a plastic film of low-density polyethylene, on perforated or non-perforated polivinyl chloride film, and compared with non-wrapping and non-irradiation as the controls. After treatments the rhizomes were maintained refrigerated at 13 deg. C and 80% relative humidity. As a main result it could be observed that dipping into paraffin and wrapping with plastics resulted in smaller weight loss of the rhizomes
[en] Carbon nanotube (CNT) wires and cables with low electrical resistivity were synthesized through a wet chemical method (dip-coating) which is inspired from the commercial metal cable production. The double-walled carbon nanotube (DWCNT) wire is composed of a Polytetrafluoroethylene (PTFE) core, a DWCNT layer coated on PTFE surface and an exterior polyimide (PI) insulating layer. The results showed that the optimal concentration of DWCNT paste for dip-coating is between 1.8 wt% and 2.0 wt%. The direction of the DWCNTs in the conducting layer is substantially oriented along with the drawing direction. The coating layer is even and the thickness of DWCNT layer is around 90 μm. And the corresponding resistivity of obtained CNTs wire is about 8.2 × 10−6 Ω·m. After treatment with iodine, its resistivity could be reduced by about 50%, reaches to 4.5·10−6 Ω·m. More importantly, the coating of PI insulation layer results in DWCNT layer densification without reducing its electrical conductivity. (paper)
[en] Highlights: • Oxygen barrier coatings solely based on nanosize cellulose were developed. • The coating thickness varied from hundreds of nanometers for spin-coated layers, to micrometers for dip-coated ones. • Nanosize cellulose coatings showed better oxygen barrier than polymers such as PE and PS in dry conditions. • Thin nanocellulose coatings were sensitive for humidity and long term storage. In this study, environmental friendly and sustainable coatings of nanocellulose (NC) were prepared using spin- and dip-coating methods, on two different porous cellulose substrates. Microscopy studies showed that spin-coating technique was suitable for the substrate with smaller pore size, while the dip-coating was suitable for the substrate with larger pore size. The coating thickness ranged from some hundreds of nanometers for the spin-coated layers, to some micrometers for the dip-coated ones. It was also seen that the contact angle increased with the coating thickness and roughness. NC coating resulted in low oxygen permeability (between 0.12 and 24 mL ∗ μm/(m2 ∗ 24 h ∗ kPa)) at 23% RH, but at 50% RH the oxygen permeability was too high to be measured, except for the dip-coated sample with 23 μm thickness. Also, it was seen that eight month storing reduced the barrier properties of the coatings when compared with fresh materials. These results indicate that NC coatings have a great potential as sustainable alternative coating on paperboard.
[en] In this paper, highly efficient and stable CuO/ZnO nanowire (CuO/ZnO-nw) based photocathode was fabricated using a facile and scalable technique for application in photoelectrochemical water splitting. Electro-deposition of Cu film on FTO glass followed by a subsequent chemical oxidation and dip-coating methods was implemented to fabricate a p-type CuO/ZnO-nw heterostructure photoelectrode. The as-prepared CuO/ZnO-nw heterostructure consisted of a copper (II) oxide (CuO) nanowire covered by zinc oxide (ZnO) nanoparticle film serving as both protecting and charge transfer layer. We optimized the coating concentration and the number of layers to achieve enhanced p-type CuO/ZnO-nw photoelectrode material. The best photocathode material exhibited a maximum current of − 8.1 mAcm−2 at 0 versus RHE. The obtained photocurrent density was outstanding compared to other reported CuO-based heterostructure photoelectrodes. The enhancement in photocurrent performance originated from the combined effect of charge separation and the light absorption properties of the heterostructure photoelectrode. The result demonstrated a simple and scalable approach for the fabrication of enhanced CuO nanowire-based photoelectrode for the production of H2 using solar light.
[en] Materials with high electromagnetic interference (EMI) shielding performances, excellent conductivity and flexibility, along with low density, have a great potential to be applied in next generation of flexible electronic devices. In the current study, one of such materials, reduced graphene oxide woven fabrics (rGWF)/poly(dimethyl siloxane) (PDMS) composites are fabricated through a facile template-directed reduction method followed by dip coating. The fabricated composite possesses a highly ordered and hierarchical porous structure, containing 3D interconnected graphene networks. The unique porous structure containing high-quality graphene architecture makes the composite exceptional EMI shielding properties. The composite containing four layers of rGWF delivers a remarkable total shielding effectiveness (SET) of 46 dB and a specific SET of 295 dB·cm3 g−1. Apart from this property, the composite also exhibits excellent durability and is capable of retaining over 94% and 98% of the original SET after 100 stretching-releasing and bending-releasing cycles, respectively. These excellent properties in EMI shielding performance, durability, and reliability give rGWF/PDMS composite a great potential to be used as emerging flexible EMI shielding materials. (paper)
[en] A variety of materials with superwetting property are fabricated for separation of immiscible oils/organic solvents and water mixture. However, the complex fabrication process, requirement of sophisticated equipment, and associated toxicity strongly limit the development of the superwetting materials. In this paper, a simple two-step dip coating strategy is demonstrated to prepare polydopamine-octadecanethiol modified 3D porous sponge with superhydrophobic and superoleophilic properties (a water contact angle of 156.8° ± 2.5° and an oil contact angle of nearly 0°) through the combination of enhanced surface roughness and low surface energy coating for separation of oil/water mixture. The as-prepared superhydrophobic sponges possess high porosity (greater than 99.2%), low density (below 10 mg/cm3), and 3D porous network structure, which meet well with the needs for adsorption of the actual oil pollutions. More importantly, in situ continuous removal of oil from oil/water mixture is successfully accomplished via a vacuum-assisted system, even in the corrosive environments including turbulent situation, heat, acidic, alkaline, seawater, and glacial water. The continuous oil collection system could avoid the limit in adsorption saturation effectively. We believe that the superhydrophobic sponge with easy large-scale production, economical, and environmentally friendly characteristics can be a superior candidate for the treatment of oily wastewater and practical oil spill accidents.
[en] The low content of polarity groups on hydrophobic fibers could exclude water molecules and hinder the further application in the surface modification of fibers. Therefore, the stable interfacial interaction between function materials and hydrophobic fibers substrate is the key challenge to endow functions. Herein, graphene oxide was employed to modify the surface of polyester non-woven fabrics (PNW) and then reduced graphene-modified polyester nonwoven fabric (rGO-PNW) was achieved via a one-step hydrothermal method with ‘reducing agent free’. The washability, hydrophobic property, electrical conductivity, thermal response and sensing performance of the obtained samples were investigated, especially, the obtained rGO-PNW exhibited excellent low electrical resistivity 52.6 Ω/m. What’s more, after 10 times of washing treatment, the resistivity change of the as-prepared rGO-PNW was much smaller than that of traditional dip-coating route, indicating a much stable interface was established between graphene layer and the hydrophobic polyester fiber under the hydrothermal condition. In addition, the water contact angle of rGO-PNW increased to 160.85°, far above that of PNW (47.42°), also, the rGO induced significant improvement in the thermal response of rGO-PNW in comparison with that of the PNW. Moreover, the rGO-PNW exhibited high sensitivity (S = 11.5 kPa−1) and repeatability in response to compression deformation. The one-step hydrothermal method could realize a better surface modification of hydrophobic fibers, and it could be an new route for the hydrophobic fabric modification. (paper)
[en] Graphical abstract: Fig. shows the steps involved in the development of the AgNW-PEDOT:PSS/PANI electrode. The bright silver nanocubes were observed onto the PANI nanofibers. This means that during the electrodeposition of PANI, there is an electrostatic interaction between AgNWs and PANI; the AgNWs are segmented into the small nanocubes. These nanocubes are distributed equally all over the interconnected network of the PANI nanofibers. This provides a continuous path for the electrons during the charge/discharge process. - Highlights: • Ag-PEDOT:PSS/PANI hybrid nanostructure was prepared. • Dip coating and electrodeposition techniques are used for electrodes preparation. • Symmetric supercapacitor based on AgNW-PEDOT:PSS/PANI was developed. • The positive synergistic effect of AgNW, PEDOT:PSS and PANI was observed. - Abstract: This paper reports the synthesis of a silver − Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)/Polyaniline(Ag-PEDOT:PSS/PANI)hybrid nanostructure using a simple dip coating technique followed by potentiodynamic electrodeposition to achieve an electrochemical supercapacitor with excellent electrochemical performance. In this sandwich type structure, the Ag nanostructure-blended PEDOT: PSS acts as a current collector, where electrons can be transferred easily through this network to the PANI nanofibers and vice versa. The AgNW-PEDOT:PSS/PANI showed a specific capacitance of 643 Fg−1 at 10 mVs−1 and an energy density of 86.19 Whkg−1 at 0.1 mA, indicating the positive synergistic effect of silver nanowires (AgNW), PEDOT:PSS and PANI. The Ag nanostructure incorporated PEDOT:PSS helps to improve the electronic conductivity and the electrochemical stability of the PANI electrodes. Promising electrochemical properties achieved from the measurement of symmetric device demonstrate the ideal capacitive behavior of our prepared electrodes.
[en] Highlights: • A facile strategy of fabricating self-healing superhydrophobic cotton fabric was exhibited. • The superhydrophobic cotton fabric showed superior resistance to various liquids and excellent durability to extreme environments. • After devastating abrasion, the fabric superhydrophobicity can be restored by brief heating treatment. For extending the lifespan of practical applications, a robust and self-healing superhydrophobic cotton fabric was successfully fabricated by facile dip coating and UV curing. The low surface energy and micro/nanoapophysis of superhydrophobic fabric were contributed by dip-coating components consisting of tri-functionality vinyl perfluoro decanol, vinyl-terminated polydimethylsiloxane and octavinyl-polyhedral oligomeric silsesquioxane. These obtained cotton fabrics exhibited superior resistance to various liquid pollutants, and had excellent resistance to the acid and alkali liquid. Furthermore, they were durable to withstand 10,000 cycles of abrasion, 120 h of accelerated weathering test and heating or freezing test. Most importantly, after 200 cycles of severe abrasion, they were able to restore the superhydrophobicity by brief heating treatment and showed excellent self-healing ability. These designed cotton fabric may contribute to the development of durable superhydrophobic textiles.