A superhydrophobic cotton textile with high antibacterial properties has been fabricated. The cotton textile was coated through the in situ growth of ZnO‐SiO2 nanoparticles in presence of chitosan as the template agent via a hydrothermal process at 95 °C. This process was followed by the coating of additional layers of hexadecyltrimethoxysilane (HDTMS). The obtained cotton textile showed antibacterial property against Staphylococcus epidermis and Escherichia coli with inhibition zones up to 18.26 and 8.48 mm, respectively. Scanning electron microscopy (SEM) revealed that the coating had a rough surface, which was attributed to the distribution of ZnO‐SiO2 nanorods of hexagonal shape. This rough surface creates a superhydrophobic layer that repels the bacteria, as proven by the large water contact angle of approximately 150°. Nevertheless, the HDTMS layers prolong the durability of hydrophobicity for up to 3 h. 相似文献
The various morphology and structure microspheres were fabricated via one‐step single‐solvent electrospraying of hydrophilic and hydrophobic block modified copolymer of polycaprolactone (PCL). A honeycomb‐like hierarchical structure microspheres of PCL‐b‐PTFOA(4h) and abundant nanometer pores of PCL‐b‐PEG400 microspheres were obtained due to the solvent evaporation, thermally and polymer diffusion‐induced phase separation effect. Furthermore, a superhydrophobic coatings and robust superhydrophobic‐coated cotton woven fabric surfaces were prepared by using PCL‐b‐PTFOA(4h) microspheres with hierarchical structure and low surface energy. The contact angle (CA) and sliding angle (SA) of PCL‐b‐PTFOA(4h) microspheres‐coated cotton woven fabric surfaces reached 164.4 ± 5.5° and 6.8 ± 0.5°, respectively, which allows for self‐cleaning. The self‐cleaning test demonstrated that the coated superhydrophobic surface could shed aqueous dyes and dust without any trace. The superhydrophobic‐coated fabric shows good soaping fastness against mechanical abrasion without significant reduction of CA. This electrospraying coating of block copolymers can provide a simple, facile, and promising technique for producing multifunctional textiles. 相似文献
The superhydrophobic cotton fabrics were prepared by combining the coating of titanium dioxide (TiO2) with the subsequent dodecafluoroheptyl-propyl-trimethoxysilane (DFTMS) modification. Scanning electron microscopy (SEM)
and X-ray diffraction (XRD) measurements revealed that the nanosized TiO2 sphere consisted of granular rutile. The TiO2 layer coated on the cotton altered both the surface roughness for enhancing the hydrophobicity and UV-shielding property.
The cotton fabric samples showed excellent water repellency with a water contact angle as high as 162°. The UV-shielding was
characterized by UV-vis spectrophotometry, and the results indicated that the fabrics could dramatically reduce the UV radiation.
The photocatalytic progress showed that organic stains were successfully degraded by exposure of the stained fabric to UV
radiation. Such multifunctional cotton fabrics may have potentials for commercial applications. 相似文献
Development of electrospun nanofiber membranes with the selective wettability characteristics for effectively separating oil–water mixtures is an extremely advisable strategy. In this study, a superhydrophobic electrospinning carbon nanofiber (F/ZnO/CNF) membrane was successfully prepared by electrospinning and in-situ growth of ZnO, and subsequent fluorination reaction with 1H, 1H, 2H, 2H-perfluorooctyltriethoxysilane (POTS). Benefiting from the influence of needle-like nanostructure and low surface energy, the as-prepared F/ZnO/CNF membrane shows excellent superhydrophobicity. When the growth duration of ZnO is 3 h, the obtained F/ZnO/CNF-3 membrane possesses outstanding water contact angle (WCA, 159.7°) and splendid oil–water separation efficiency (>99 %). Meanwhile, due to its the superior environmental stability the obtained F/ZnO/CNF-3 membrane exhibits excellent low and high temperature resistance, and enhanced resistance to various organic solvents in the face of a series of harsh environments. 相似文献
Functional differences between superhydrophobic surfaces, such as lotus leaf and rose petals, are due to the subtle architectural features created by nature. Mimicry of these surfaces with synthetic molecules continues to be fascinating as well as challenging. Herein, we demonstrate how inherently hydrophilic alumina surface can be modified to give two distinct superhydrophobic behaviors. Functionalization of alumina with an organic ligand resulted in a rose‐petal‐like surface (water pinning) with a contact angle of 145° and a high contact angle hysteresis (±69°). Subsequent interaction of the ligand with Zn2+ resulted in a lotus‐leaf‐like surface with water rolling behavior owing to high contact angle (165°) and low‐contact‐angle‐hysteresis (±2°). In both cases, coating of an aromatic bis‐aldehyde with alkoxy chain substituents was necessary to emulate the nanowaxy cuticular feature of natural superhydrophobic materials. 相似文献
Summary: Hydrophilic acrylic nanofibers were prepared from alkaline hydrolysis of hydrophobic polyacrylonitrile (PAN) nanofibers. Water contact angle, pore volume, and liquid retention capacity of PAN nanofibrous membranes were measured to determine their dependence on hydrolysis parameters such as base concentration, temperature, and time. Vertical water retention capacity of hydrolyzed PAN nanofibrous membrane could reach as large as 200 times of that of original membrane.
Fiber twinning in post‐hydrolyzed PAN nanofibrous membrane. 相似文献
There is increasing demand for superhydrophobic materials, which can be used for separating oil and water efficiently. To avoid secondary pollution, it is desirable to prepare such materials with green technology. Here, we present an environmentally benign method for fabricating superhydrophobic materials by using organic base based solvents in which cellulose can be dissolved and activated. The dissolved cellulose could be chemically modified with a silanization reagent, and the solvent could be recycled after CO2 was removed. The obtained cellulose nanocoating exhibited excellent hydrophobic effects. By spraying it on filter paper (water contact angle (WCA)=165°) for oil and water separation, the separation efficiency of more than 95 % was achieved; ultrasonication of an ordinary sponge in its dispersion (WCA=163°), meant it could be used as an oil absorber. It can also absorb a certain amount of bisphenol A (BPA), with the concentration decreasing by 66 % from the original concentration (0.1 mm ). Besides the high separation efficiency, it is resistant to a wide range of pH solutions, which means that it could be used in harsh environments. More importantly, the process is cost‐effective, the solvent can be recycled, and the whole process is green. Thus, the activation method provides a green route for the preparation of other cellulose‐based materials. 相似文献
Inorganic nanowire aerogel with low density, high specific surface area and high porosity has received increasing attention in the field of materials physics and chemistry because of not only the unique structural and physical features of metallic oxide but also low cost, environmental friendliness and earth abundant of precursor materials. In this work, MnO2 nanowire aerogels (MNA) with ultralow density, and stable 3D hierarchical structures was successfully fabricated by freeze‐drying processes using MnO2 nanowire as building blocks. The length of MnO2 nanowires exceeds 100 μm, making it easier to cross‐link and self‐assemble into a 3D network of aerogels, and the acid and alkali resistance of MnO2 enables it to adapt to extreme environments. Simultaneously, the monodispersed MnO2 nanowire was prepared by the hydrothermal method, followed by acid treatment. To obtain superhydrophobic properties and achieve selective oil adsorption, the surfaces of nanowire aerogels were grafted the hydrophobic groups with low surface energy via vapor deposition. It is indicated that the obtained 3D hierarchical MNA show both superhydrophobic and super‐lipophilic properties simultaneously with a high‐water contact angle of 156° ± 2° and an oil contact angle of 0°. And the MNA exhibited a high oil adsorption capacity of 85–140 g/g, thereby indicating its potential applications in oil/water separation. More importantly, the resulting MNA can be recycled ten cycles without loss of oil absorption capacity (more than 120 g/g). The results presented in this work demonstrate that the as‐prepared nanowire aerogel may find applications in chemical separation and environmental remediation for large‐scale absorption of oils from water. 相似文献
Highly porous polypyrrole (PPy)‐coated TiO2/ZnO nanofibrous mat has been successfully synthesized. The core TiO2/ZnO nanofibers have an average diameter of ca. 100 nm and the shell of ultrathin PPy layer has a thickness of ca. 7 nm. The NH3 gas sensor using the as‐prepared material exhibited a fast response over a wide dynamic range and high sensitivity with a detection limit of 60 ppb (S/N=3). Compared to conventional pristine PPy film, the improved performance in NH3 detection can be attributed to the free access of NH3 to PPy and a minimized gas diffusion resistance through the ultrathin PPy layer. 相似文献
Exploiting a superhydrophobic surface is very significant due to its excellent water repellency which has many practical applications in various fields. In this work, the cobalt incorporated amorphous carbon‐based (Co/a‐C:H) film was prepared successfully on Si substrate via a simple 1‐step electrochemical deposition where electrochemical deposition technology was using cobalt (II) acetylacetonate methanol solution as electrolyte under high voltage, atmospheric pressure, and low temperature. Surprisingly, the as‐prepared film showed a superior superhydrophobic surface with a water contact angle of 153 ± 1° and a sliding angle of 7.6° without any further modification of low surface energy materials. Especially, the tape adhesive, corrosion resistance, and self‐cleaning tests demonstrated that the as‐prepared carbon‐based film could possess fairly well adhesion, superior anti‐corrosion resistance, and self‐cleaning ability, respectively. It indicated that the superhydrophobic Co/a‐C:H film might have potential promising applications in the field of anti‐fouling, anti‐corrosion, and drag resistance, such as the above‐deck structures on icebreaker vessels, ship hulls, and offshore wind turbine blades. 相似文献
Robust superhydrophobic surface exhibiting anti-fouling and self-cleaning ability were successfully fabricated by nano TiO2 modified by γ-aminopropyltriethoxysilane (KH550) and polydimethylsiloxane (PDMS) via wire rod coating. Due to the lower surface energy of PDMS and the hierarchical structure caused by the different aggregation sizes of TiO2 nanoparticles, the contact angle of the resulting superhydrophobic coating was 154.5° and the rolling angle was 3.5°. And the coated paper still had good non-wettability under water immersion. In addition, the coated paper was tolerant to mechanical damage and various temperature conditions. Even after 40 sandpaper wear cycles, the coating can still maintain good mechanical stability and superhydrophobicity. The superhydrophobic paper was used for oil-water separation, the separation efficiency was about 98% even after used 10 times. Furthermore, the prepared superhydrophobic paper exhibited excellent self-cleaning and anti-fouling properties, as well as demonstrated superb resistance to various water solutions owing to its high hydrophobicity. Moreover, the prepared superhydrophobic paper has application prospects in the industry of special wetting materials. 相似文献
PANI‐PAN coaxial nanofibers have been prepared by electro‐spinning during polymerization. The surface of the resulting nanofibers is superhydrophobic with a water contact angle up to 164.5°. Conductivity of the PANI‐PAN nanofibers is about 4.3 × 10−2 S · cm−1. The superhydrophobic nanofibers show a chemical dual‐responsive surface wettability, which can be easily triggered by changing pH value or redox properties of the solution. A reversible conversion between superhydrophobicity and superhydrophilicity can be performed in a short time. The strategy used here may provide an easy method to control the wettability of smart surfaces by using properties of low‐cost functional polymers.
A superhydrophobic surface with maximum static water contact angle of 156° and sliding angle of 3.5° was fabricated by modifying the silica coated multiwalled carbon nanotube composites (SiO2/MWCNTs) using a silane coupling agent vinyltriethoxysilane. The structures of SiO2/MWCNTs and superhydrophobic surface were investigated by infrared spectrometer and transmission electron microscopy. The results indicated that silica had been successfully grafted onto MWCNTs and the SiO2/MWCNTs had been chemical modified by vinyl triethoxy successfully. The morphology of our prepared superhydrophobic surface, investigated by scanning electron microscopy, showed a characteristic rough structure. The effects of pH value and exposure time on the stability of the superhydrophobic surface were also investigated. The superhydrophobic film shows reliable acid and alkali resistance and aging resistance, indicating that it will have a wide range of applications. 相似文献
UV radiation causes serious damage to skin, and a protective system capable of absorbing or reflecting UV radiation is required
to protect skin. This paper describes the UV protection and photocatalytic properties of TiO2 nanofilm coated electrospun polyacrylonitrile (PAN) nanofibrous mats with various nanofiber diameter and area density. The
mats were coated by sol–gel process. The results of this research showed that sol–gel is capable of coating porous nanofibrous
mats with a weight increase as low as 0.8%. The TiO2 nanofilm coated on the nanofibrous mats has a considerable effect on its UV protection. The UV protection factor (UPF) of
the mats increases with decreasing nanofiber diameter. In fact decreasing the diameter of nanofibers of the TiO2 nanofilm coated PAN nanofibrous mats increases their photocatalytic activity. Moreover, this research showed that TiO2 nanofilm produced through sol–gel process on the PAN nanofibers has a crystalline structure. The UPF of the nanofibrous mat
coated with a TiO2 nanofilm via sol–gel process can be classified as excellent. 相似文献
Nowadays, most superhydrophobic surfaces will lose their superhydrophobic performance once they encounter oil, and adhesive strength of superhydrophobic coating is low. Therefore, the superhydrophobic coating with good oleophobicity and high adhesive strength is popular with people. A superhydrophobic and oleophobic coating is characteristic of antifouling and self-cleaning, due to the appearance of special structures, such as overhang and re-entrant. In this work, flower-like zinc oxide (ZnO) particles free of fluorine and fluorine-containing epoxy were used to establish the coating with a similar re-entrant structure. Flower-like ZnO particles were prepared by a chemical precipitation method, and the water contact angle of flower-like ZnO is up to 149 ± 1°. For the coating, flower-like ZnO particles were almost covered by fluorine-containing epoxy synthesized through click reaction so that the adhesive strength between the coating and the matrix is high, superior to some coatings in the references. The surfaces made of flower-like ZnO and fluorinated epoxy possess superhydrophobic and oleophobic properties. The contact angle of the coating for water, diiodomethane, glycerol, and glycol is 154 ± 0.7°, 138 ± 0.6°, 156 ± 0.7°, and 150 ± 0.7°, respectively. After withstanding 70 cycles under the pressure of 1 kPa, the coating is still superhydrophobic. Also, the coating possesses a good self-cleaning and anti-icing property. 相似文献