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1.
Three reusable and durable superhydrophobic nanofibrous filters were prepared by dip coating the nanofibrous fabric in the three different dispersed solutions of the newly modified nanoparticles (ZnO‐NSPO, AlOO‐NSPO, and titanium dioxide [TiO2]‐NSPO). The contact angle results proved that the TiO2‐NSPO coated nanofibrous polyacrylonitrile (PAN) filter was hydrophobic with the water contact angle (WCA) of 141° while the ZnO‐NSPO and AlOO‐NSPO coated nanofibrous PAN filters were superhydrophobic with the WCA of 168° and 152°, respectively. The as‐prepared filters can be utilized as an effective martial for oil‐water separation with separation efficiency of over 98%.  相似文献   

2.
《中国化学会会志》2017,64(11):1347-1353
Since textiles have a porous and hydrophilic structure, they are ideal substrates for the settlement and growth of pathogenic bacteria. Therefore, fabrication of hydrophobic textiles to reduce their humidity has the potential to inhibit the growth of bacteria. On this basis, we report here an improvement of the antibacterial capability of textiles coated with TiO2–SiO2/chitosan using hydrophobization. Synthesis of TiO2–SiO2 clusters with chitosan was carried out using the sol–gel technique. In addition, hydrophobization of the textiles using hexadecyltrimethoxysilane (HDTMS) was carried out using a dip‐spin coating method. In addition, their characteristics were examined using X‐ray diffraction (XRD), scanning electron microscopy (SEM), UV–vis diffuse reflectance spectra (UV‐DRS), Fourier transform infrared (FTIR), water contact angle, and antibacterial activity. XRD, SEM, UV‐DRS, FTIR, and water contact angle confirmed the physical and chemical properties of the modified textiles. In summary, the present work shows that the hydrophobization of textiles using HDTMS can enhance the antibacterial capability of cotton textiles.  相似文献   

3.
This paper focuses on the preparation of a superhydrophobic coating on glass/porcelain insulators which possess anti-icing property below freezing temperature. Inspired by lotus-effect, the fabrication of a superhydrophobic coating has two steps: the first step is to construct a hierarchical SiO2 coating on the substrate surface, and the second step is the chemical modification of the SiO2 coating with 1H,1H,2H,2H-Perfluorodecyltriethoxysilane (PDTS). The precursor for the hierarchical SiO2 coating is a suspension of SiO2 sol particles and dispersible SiO2 powder particles. According to the TEM testing, SiO2 sol particles prepared by sol–gel method has an average particle size about 2–5 nm, while the size of the dispersible SiO2 particles is ca. 20 nm. The precursor was sprayed on glass/porcelain insulators, and then dried at ambient condition, finally heat-treated at 773 K for 2 h. The morphology of the superhydrophobic coating was characterized by TEM and AFM, and experimental results indicated that the coating featured [hierarchical structure consisting of both large bumps with micron-sized height (0.8 μm) and tiny papillae with the size about 30 nm] micron-sized roughness (0.8 μm) combined with nano-sized roughness (about 2 nm). Moreover, the scratch test showed that the coating tightly adhered to the surface of the glass/porcelain insulators. The superhydrophobic property of the coating was examined by a contact angle measurement, and the results demonstrated that the static water contact angle is high up to 163.6°, and the sliding angle is 1.4°. The superhydrophobic property of the coating was also confirmed by the outdoor tests in winter, and it was found that the superhydrophobic coating had the function in anti-icing, based on which the anti-icing mechanism underlying was discussed in terms of the interaction between impacting droplets and superhydrophobic surface.  相似文献   

4.
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   

5.
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   

6.
We report here a simple strategy for fabricating asymmetrically superhydrophobic cotton fabric via a mist copolymerization of three monomers, 2,2,2‐trifluoroethyl methacrylate (TFMA), 2‐isocyanatoethyl methacrylate (IEM), and divinylbenzene (DVB). The copolymer layer on the cotton surface was confirmed by X‐ray photoelectron spectroscopy (XPS) analysis and attenuated total reflection (ATR) accessory, and the nanoscale hierarchical structures in the polymeric layer were demonstrated by observation of field emission scanning electron microscope (FE‐SEM). Surface characterization reveals that the modified surface is superhydrophobic, but the opposite side of the modified cotton fabric has the hydrophilic nature of cotton. More experimental data suggest that the good water adsorptivity and vapor transmissibility of the original cotton fabric were inherited after the surface modification. These properties are of great significance in textile and medical applications. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 1862–1871  相似文献   

7.
Fabrication of polymer‐carbon composite nanostructure with good dispersion of each other is critical for the desired application due to the nanostructure flaws, agglomeration, and poor absorption between the 2 materials. Fabrication of superhydrophobic surface coating composites of polytetrafluoroethylene (PTFE) with multiwalled carbon nanotubes (MWCNTs) through supercritical fluid processing was explored in this study. Homogeneity of the composite was characterized by X‐ray diffraction and Raman spectroscopy studies, which reveal that the PTFE and MWCNT are uniform in the composite. Microstructural surface evaluation of field‐emission scanning electron microscope and high‐resolution transmission electron microscope studies display that the coating composite possesses roughness structures and fibrillation of the superhydrophobic surface coating. Superhydrophobic character was evaluated on fiber‐reinforced plastic (FRP) sheets, which showed that the prepared coating composite surface showed self‐cleaning properties with a high water contact angle of 162.7°. The surface wettability was studied by increasing different temperatures (30°C to 300°C) in PTFE‐MWCNT composite, which reveals that the FRP sheets were thermally stable up to 200°C and afterward; they transformed from superhydrophobic to hydrophilic state at 250°C. The superhydrophobic surfaces are thermally stable in extreme environmental conditions, and this technique may be used and extendable for large‐scale applications.  相似文献   

8.
Multifunctional epoxy‐polydimethylsiloxane nanocomposite coatings with antifouling and anticorrosion characteristics have been developed via in situ polymerization method at different loading (1, 3, and 6.5 wt.%) of ZnO nanoparticles to cater marine applications. A detailed comparative analysis has been carried out between epoxy‐polydimethylsiloxane control (EPC) and ZnO‐reinforced coatings to determine the influence of ZnO loading on various properties. The incorporation of ZnO in EPC led to increase in root mean square (RMS) roughness to 126.75 nm and improved hydrophobicity showing maximum contact angle of 123.5° with low surface energy of 19.75 mN/m of nanocomposite coating as compared with control coating. The differential scanning calorimetry (DSC) result indicated improved glass transition temperature of nanocomposite coatings with highest Tg obtained at 83.69°C in case of 1 wt.% loading of ZnO. The increase in hydrophobicity of the system was accompanied by upgraded anticorrosion performance exhibiting 98.8% corrosion inhibition efficiency (CIE) as compared with control coating and lower corrosion rate of 0.12 × 10?3 mm/year. The Taber abrasion resistance and pull‐off adhesion strength results indicated an increment of 34.7% and 150.7%, respectively, in case of nanocomposite coating as compared with the control coating. The hardness of nanocomposite coatings was also improved, and maximum hardness was found to be 65.75 MPa for nanocomposite coating with 1 wt.% of ZnO. Our study showed that the nanocomposite coating was efficient in inhibiting accumulation of marine bacteria and preventing biofouling for more than 8 months. The developed environment‐friendly and efficient nanocomposite material has a promising future as a high‐performance anticorrosive and antifouling coating for marine applications.  相似文献   

9.
Optically transparent hydrophobic and superhydrophobic coatings have been prepared using polyamide 12–SiO2 nanocomposite (NC) on glass substrates by the spin‐coating method. The coatings have been optimized for their hydrophobicity and transparency. The transformation from hydrophobic to superhydrophobic is achieved with increase in roughness (Ra) which increases with SiO2 content. These coatings are highly transparent in the entire visible region (400–800 nm). The influence of layer thickness on water contact angle (WCA) and optical transmittance of the coatings has been studied. Field emission scanning electron micrograph (FESEM) shows the presence of SiO2 nanoparticles covered with polyamide homogenously on the surface and the particles are aggregated to form a rough structure. X‐ray diffraction (XRD) patterns show that the polyamide losses its crystalline structure in the composite. The preparation procedure reported here is simple and eco‐friendly. The dual nature of the coatings, that is, high transparency and superhydrophobicity in the entire visible region suggests for its potential usage in self‐cleanings, wind screen and optoelectronic applications. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

10.
The relationship between the contact angles, surface tension, and surface roughness is reviewed. Numerical formulas related to the superhydrophobic rough surfaces of polymers are predicted with two approaches, the Wenzel and Cassie–Baxter models. With these models as a guide, an artificial superhydrophobic surface is created. Rough nylon surfaces mimicking the lotus leaf are created by the coating of a polyester surface with nylon‐6,6 short fibers via the flocking process. Poly(acrylic acid) chains aregrafted onto nylon‐6,6 surfaces, and this is followed by the grafting of 1H,1H‐perfluorooctylamine onto the poly(acrylic acid) chains. Water contact angles as high as 178° are achieved. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 253–261, 2007.  相似文献   

11.
An ultrathin poly(methyl methacrylate) (PMMA) buffer layer was developed to improve the performance of n‐channel organic thin‐film transistors (OTFTs). The 8 nm‐thick PMMA film, prepared by spin‐coating, provided a very smooth surface and a uniform coverage on SiO2 surface reproducibly, which was confirmed by X‐ray reflectivity (XR) measurement. Then, we fabricated N,N′‐ditridecyl‐3,4,9,10‐perylenetetracarboxylic diimide (PTCDI‐C13) thin‐film transistors with and without this 8 nm‐thick PMMA insulating layer on SiO2 gate insulators and achieved one‐order increase of field‐effect mobility (up to 0.11 cm2/(Vs) in a vacuum), one‐half decrease of threshold voltage, and reduction of current hysteresis with the PMMA layer. Only TFTs with the PMMA layer displayed n‐channel operation in air and showed field‐effect mobility of 0.10 cm2/(Vs). We consider that electrical characteristics of n‐channel OTFTs were considerably improved because the ultrathin PMMA film could effectively passivate the SiO2 insulator surface and decrease interfacial electron traps. This result suggests the importance of the ultrathin PMMA layer for controlling the interfacial state at the semiconductor/insulator interface and the device characteristics of OTFTs. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

12.
Cr‐doped TiO2/SiO2 nanostructured materials were prepared employing a layer‐by‐layer assemblym technique. TiO2 colloids were synthesized by a sol‐gel method using TiCl4 as a precursor. The experimental results showed that sphere‐type TiO2 particles on SiO2 exhibited uniform shape and a narrow size distribution. The amount of Ti (wt %) increased as a function of the number of the coating layers. The coatingv layers was composed of anatase titania nanocrystals at 550 °C. The onset of band‐gap transition for Crdoped TiO2/SiO2 showed a red shift compared with that for the undoped TiO2/SiO2. And the photocatalytic activity of Cr‐doped TiO2/SiO2 was higher than that of undoped sample.  相似文献   

13.
Hydrophilic alumina (Al2O3) nanoparticles (25, 35, and 150 nm) are dispersed in different concentrations in solutions of a commercial hydrophobic poly(alkyl siloxane) (Silres BS‐290), and the suspensions are sprayed on glass surfaces. Static contact angles (θS), measured on surfaces of siloxane‐nanoparticle composite films that were prepared from dilute dispersions, increase rapidly with particle concentration. Composite films prepared from concentrated dispersions exhibit a maximum, constant θS (at saturation θS is 160°), which is not affected by the size of the particles. These films exhibit also very small contact angle hysteresis (5°), which is also independent of the particle size. Consequently, the same superhydrophobic character can be induced in siloxane films using nanoparticles, which can range from a few up to several tenths of nanometers. However, the particle size and more precisely the particle specific surface area affects dramatically the minimum critical particle concentration, which must be used in the dispersions to induce superhydrophobicity on the surface of the composite films, that is, to achieve θS = 150°. It is shown that critical particle concentration decreases exponentially with specific surface area. This result can be important for manufacturers of superhydrophobic surfaces who are interested in having a good control on the wettability of the composite films. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

14.
A series of amphiphilic silica/fluoropolymer nanoparticles of SiO2g‐P(PEGMA)‐b‐P(12FMA) were prepared by silica surface‐initiating atom transfer radical polymerization (SI‐ATRP) of poly(ethylene glycol) methyl ether methacrylate (PEGMA) and poly dodecafluoroheptyl methacrylate (P12FMA). Their amphiphilic behavior, lower critical solution temperature (LCST), and surface properties as protein‐resistance coatings were characterized. The introduction of hydrophobic P(12FMA) block leads SiO2‐g‐P(PEGMA)‐b‐P(12FMA) to form individual spherical nanoparticles (~150 nm in water and ~170 nm in THF solution) as P(PEGMA)‐b‐P(12FMA) shell grafted on SiO2 core (~130 nm), to gain obvious lower LCST at 36–52 °C and higher thermostability at 290–320 °C than SiO2‐g‐P(PEGMA) (LCST = 78–90 °C, Td = 220 °C). The water‐casted SiO2‐g‐P(PEGMA)‐b‐P(12FMA) films obtain much rougher surface (125.3–178.4 nm) than THF‐casted films (11.5–16.9 nm) and all SiO2‐g‐P(PEGMA) films (26.8–31.3 nm). Therefore, the water‐casted surfaces exhibit obvious higher water adsorption amount (Δf = ?494 ~ ?426 Hz) and harder adsorbed layer (viscoelasticity of ΔDf = ?0.28 ~ ?0.36 × 10?6/Hz) than SiO2‐g‐P(PEGMA) films, but present loser adsorbed layer than THF‐casted films (ΔDf = ?0.29 ~ ?0.63 × 10?6/Hz). While, the introduction of P(12FMA) segments does not show obviously reduce in the protein‐repelling adsorption of SiO2‐g‐P(PEGMA)‐b‐P(12FMA) films (△f = ?15.7 ~ ?22.3 Hz) compared with SiO2‐g‐P(PEGMA) films (△f = ?8.3 ~ ?11.3 Hz) and no obvious influence on water adsorption of ancient stone. Therefore, SiO2‐g‐P(PEGMA)‐b‐P(12FMA) is suggested to be used as protein‐resistance coatings. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 381–393  相似文献   

15.
A study on poly(tetrafluoroethylene) (PTFE) reinforced with tetraethoxysilanes (TEOS) derived SiO2 is described. It included the manufacturing process of SiO2‐reinforced PTFE and the effects of silylation agent on the properties of the hybrid material, such as porosity, hydrophobic, thermal resistance, dielectric and mechanical properties, and microstructure. PTFE/SiO2 hybrids of 50 wt % SiO2 loading were prepared via a sol–gel process and were shaped by a two‐roll milling machine. Trimethylchlorosilane and hexamethydisilazane were used as the silylation agents. Our results showed that the water absorption and dielectric loss of PTFE/SiO2 hybrid had significantly improved with silylation agent. The silylation process replaced Si? OH with Si? CH3 on the surface of the TEOS‐derived silica colloidal particle. The existence of trimethylsilyl [? Si(CH3)3] on the surface of the modified PTFE/SiO2 hybrid was confirmed via infrared and solid‐state 29Si magic‐angle spinning nuclear magnetic resonance spectra. Nitrogen‐sorption techniques were used to characterize the modified and unmodified PTFE/SiO2 hybrids. The microstructure of SiO2 in the matrix was also evaluated with scanning electron microscopy and transmission electron microscopy. Our results showed that the silylated sol–gel‐derived PTFE/SiO2 hybrids had exhibited high porosity (53.7%) with nanosize pores (10–40 nm) and nanosize colloidal particles (20–50 nm). This manifests itself as have the ultralow dielectric properties (Dk = 1.9 and Df = 0.0021), low coefficient of thermal expansion (66.5 ppm/°C), high tensile modulus (141 MPa), excellent thermal resistance (Td = 612 °C), and an increased hydrophobia (θ = 114°); moreover, the hydrophobic property of the PTFE/SiO2 hybrid was thermally stable up to 400 °C. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 1789–1807, 2004  相似文献   

16.
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   

17.
A series of superhydrophobic poly(methacryloxypropyltrimethoxysilane, MPTS‐b‐2,‐2,3,3,4,4,4‐heptafluorobutyl methacrylate, HFBMA)‐grafted silica hybrid nanoparticles (SiO2/PMPTS‐b‐PHFBMA) were prepared by two‐step surface‐initiated atom transfer radical polymerization (SI‐ATRP). Under the adopted polymerization conditions in our previous work, the superhydrophobic property was found to depend on the SI‐ATRP conditions of HFBMA. As a series of work, in this present study, the effects of polymerization conditions, such as the initiator concentration, the molar ratio of monomer and initiator, and the polymerization temperature on the SI‐ATRP kinetics and the interrelation between the kinetics and the surface properties of the nanoparticles were investigated. The results showed that the SI‐ATRP of HFBMA was well controlled. The results also showed that both the surface microphase separation and roughness of the hybrid nanoparticles could be strengthened with the increase of the molecular weight of polymer‐grafted silica hybrid nanoparticles. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010  相似文献   

18.
针对目前用于油/水分离的超疏水材料普遍存在的原料不环保、不可降解、涂层耐久性差等缺点,采用简便的浸渍法,制备了一种环保、工艺简单且性能优良的超疏水材料。首先,使用水性聚氨酯(WPU)将聚甲基丙烯酸甲酯-甲基丙烯酸缩水甘油酯P(MMA-r-GMA)微球固定在棉织物表面,构造微纳米级粗糙结构。其次,通过水解-缩合反应,将无毒的十六烷基三甲氧基硅烷(HDTMS)与甲基三乙氧基硅烷(MTES)锚定在棉织物表面,制备得到超疏水棉织物。结果表明,改性棉织物接触角最高可达157.3(°),滚动角为5(°)。同时具有很好的耐溶剂性,在酸碱溶液中浸泡30 min后,接触角几乎无变化。油水分离效率最高可达97.8%,即使在经过10次循环分离之后,油水分离效率仍然在95%以上。该超疏水织物具有出色的油水分离效率和优良的稳定性,可用于可持续且环保的油水分离领域。  相似文献   

19.
The conservation of historic sculptures is receiving growing attention because of the increasing air pollution. A hydrophobic silica coating was synthesized to protect historic sculptures from weathering by starting from a solution of tetraethoxyorthosilicate (TEOS) precursor using hexadecyltrimethoxysilane (HDTMS) as hydrophobic modifier in the presence of ammonia as a catalyst. The molar ratio of ethanol, TEOS, H2O and NH4OH was kept constant at 8:0.045:3:2.8 and the molar ratio of HDTMS/TEOS (M) was varied from 0 to 0.458. The organic modification was confirmed by infrared spectroscopic studies, and the hydrophobicity of the coating was tested by the contact angle measurements. The stone surface morphology of sample treated with silica coating was characterized. The results showed that the nanocomposites were composed of spherical particles with grain size of about 190 nm in diameter. After the limestone's surface was modified, the contact angle of limestone increased from 20° to 100° for M0.458. The protective performance evaluated with its ability to resist acid rain reveals that the protective effects are satisfying.  相似文献   

20.
《先进技术聚合物》2018,29(1):254-262
Membrane technology has been successfully applied for the removal of dyes from wastewater in the textile industry. A novel poly(vinylidene fluoride) (PVDF) membrane was prepared via blending with different dosages of Ag‐TiO2‐APTES composite for dyeing waste water treatment in our study. And the effect of Ag‐TiO2‐APTES blended into the PVDF membrane was discussed, including the rejection rate of methylene blue (MB) dye, membrane morphology, surface hydrophilicity, antibacterial activity, and a certain photocatalytic self‐cleaning performance. X‐ray diffraction and Fourier transform infrared characterization confirmed that Ag‐TiO2 was functionalized by amount of hydroxyl group (−OH) and amino group (NH−), which provided by APTES. Contact angle measurement certified that the hydrophilicity of the membrane surface increased, with the contact angle decrease to 61.4° compared with 81.8° of original PVDF membrane. MB rejection rate was also increased to 90.1% after addition of Ag‐TiO2‐APTES, and the rejection of original membrane was only 74.3%. The morphologies of membranes were observed by scanning electron microscope, which indicated that Ag‐TiO2‐APTES had a good dispersion in membrane matrix and also improved the microstructure of membranes. Besides, UV irradiation experiments were performed on the composite films contaminated by MB, and the result showed that Ag‐TiO2‐APTES nanoparticle provided PVDF membrane with a certain photodegradation capacity under UV irradiation. Moreover, antibacterial activity of the composite membrane was also demonstrated through antibacterial experiment, Escherichia coli as the representative bacteria. Perhaps, this research may provide a new way for PVDF blending modification.  相似文献   

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