超疏水铜表面的制备及其耐腐蚀性能研究

首先采用高速电火花切割技术构造出表面粗糙结构,然后通过浸泡硬脂酸乙醇溶液降低材料表面能的方法成功地制备了具有超疏水特性的铜基体表面。用扫描电镜、接触角测量仪、电化学工作站、X射线衍射仪分别对材料表面结构、润湿性、耐腐蚀性、化学组成进行了表征。结果表明:经过电火花线切割处理后,基体表面分布有亚微米-微米级颗粒结构。经过硬脂酸修饰后,铜基体表面与水的接触角为153°±1.5°,表现出超疏水性。在3.5%NaCl溶液中极化测试试样表面,相对于没有处理的铜基体,超疏水表面的腐蚀电流下降了2个数量级,表现出良好的耐腐蚀性。     

溶剂对PET的诱导结晶作用

应用偏光显微镜等方法,考察了12种溶剂对PET的诱导结晶作用,表明与热结晶一样存在成核和增长两过程;增长速度和形成的球晶尺寸均与熔剂分子大小、极性等有关:诱导结晶速度快于渗透扩散速度等,所以溶剂诱导结晶动力学符合扩散动力学之说是值得商榷的。溶剂诱导结晶的形态可分为表面呈球状结构和不呈现球状结构二种类型,从断面观察分析球状结构形态仅在表面形成。发现球晶脱落漂于溶剂。     

环氧树脂偶联纳米颗粒制备超疏水表面

利用激光加工在钛合金表面构建微米级粗糙结构,采用环氧树脂溶液和纳米二氧化硅分散液对该表面进行涂覆处理,对得到的微/纳分级粗糙表面进行全氟硅烷修饰,得到具有超疏水性的复合膜层,并采用扫描电子显微镜、三维形貌仪、接触角测量仪评价膜层的形貌结构和润湿性。结果表明,激光加工构建的微米级结构和纳米二氧化硅颗粒组成的微/纳二元粗糙结构对超疏水表面的构建具有重要作用;复合膜层表面的接触角随二氧化硅分散液溶度的提高呈现先增加后减小趋势,并最终逐渐稳定在150 °左右;在二氧化硅分散液溶度为12.0 g/L时,复合表面的接触角最大,可达159 (°)。     

铝基微纳米结构超疏水表面制备及其防冰/霜性能

[目的]在铝上构建具有粗糙微纳米结构的超疏水表面,可赋予其良好的防冰/霜性能。但在实际应用中铝的超疏水性会逐渐变差甚至失效,微纳米结构的稳定性是影响疏水耐久性的主要因素之一。[方法]先通过二次阳极氧化在铝表面制备纳米多孔结构,再用不锈钢筛网模板压印的方法在铝表面获得微米级结构,扩孔处理后采用低表面能物质(如三乙氧基-1H,1H,2H,2H-十三氟代正辛基硅烷)进行修饰,最终获得了微纳米结构的铝基超疏水表面(标记为MN-SHS),并就其表面形貌、水接触角、液滴粘附性、防冰/霜性能和耐久性与只进行二次阳极氧化的铝试样和进行二次阳极氧化+扩孔的铝试样作对比。[结果]MN-SHS样品表面的水接触角达到164°,液滴粘附性低,防冰/霜性能和耐久性最优。[结论]采用阳极氧化结合微米压印技术可制得具有微纳米复合结构的铝基超疏水表面,在防冰/霜方面具有很好的应用前景。     

高密度聚乙烯超疏水膜疏水性能的研究

在优化高密度聚乙烯(HDPE)超疏水膜制备工艺的基础上,分别加入纳米二氧化钛(nano-TiO2)颗粒和微米级聚苯乙烯(PS)球对超疏水膜进行改性。研究表明:nano-TiO2更适宜作为HDPE超疏水膜的改性剂,当其添加量为8%时,超疏水膜的硬度显著提高且同时保持较好的超疏水特性。PS虽与HDPE相容性较好,但易在良溶剂的影响下对超疏水膜表面的微观结构产生不利影响,从而降低超疏水膜的自清洁性能。     

铜基超疏水表面的电沉积法制备及其耐蚀性能研究

采用电沉积(ED)方法在铜基上制得了由微球和微孔构成的微米级粗糙表面,用过硫酸钾和氢氧化钠的混合溶液处理后,在镀层上形成了Cu(OH)2纳米条/CuO微球的微纳米粗糙结构,再经过氟硅烷修饰得到超疏水表面。表面的静态接触角(CA)最大达到了158.5°。在3.5%(wt)的NaCl溶液中用三电极体系测得了实验制备的超疏水表面的极化曲线,腐蚀电位比光滑铜表面正移了23 mV,腐蚀电流降低了2个数量级,缓蚀效率高达97.7%。为超疏水表面的实用性探索提供基础。     

表面凝胶化技术构建粗糙细微结构

在醇溶性氟化聚合物（FR）溶液中,以正硅酸乙酯（TEOS）和甲基三乙氧基硅烷（MTES）为前体,并掺杂聚四氟乙烯（PTFE）,在酸性和水量不足的条件下,得到了均匀的复合溶胶。涂敷后,经表面凝胶化技术处理,使涂层表面得到微米级PTFE粒子和纳米级SiO2粒子相结合的微米纳米阶层结构。XPS证实了凝胶化只在涂层表面发生,SEM观察到涂层表面的形貌与荷叶表面极其相似,该方法可用于制备超疏水性功能涂层材料。     

喷涂法制备硅藻土/Al2O3超疏水涂层的研究

以微米级硅藻土和纳米级氧化铝粒子为原料，构筑具有一定粗糙结构的表面，以十六烷基三甲氧基硅烷（HDTMOS）为低表面能改性剂，以环氧树脂为粘接剂，制得硅藻土/Al2O3基复合超疏水涂层。首先，通过HDTMOS水解液对硅藻土和氧化铝粒子进行表面改性，再加入环氧树脂溶液获得悬浮液，采用喷涂法将上述悬浮液喷涂于基底表面，经加热固化后得到超疏水涂层。通过单因素实验筛选出最佳制备工艺（ V(HTDMOS)∶V(乙醇)=0.04∶1；m(硅藻土)∶m(Al2O3) =1.5∶0.8；m(E51)∶m(丙酮) =1∶5），其表面水静态接触角高达163.4°，扫描电镜观察其表面呈粗糙度均匀的微观分级结构。涂层适用于滤纸、木块、不锈钢板等多种基底，均可表现出优异的超疏水性能。同时，该涂层经过100次的循环磨损实验后，其表面水静态接触角仍高达146.3°。     

仿生微模塑制备超疏水半透明隔热ATO/PU复合薄膜

掺锑二氧化锡(ATO)基透明隔热涂层或贴膜是一种节能新材料,但其表面不耐脏,超疏水化可解决此问题。今在聚二甲基硅氧烷(PDMS)软模板上,采用溶液浇注微模塑法制得了不同ATO含量的ATO/水性聚氨酯(WPU)复合功能膜,其水静态接触角达(151.3±2.1)°,水滴在膜表面极易滚落,同时具有优良的隔热性能和半透明性。扫描电子显微镜(SEM)表征了薄膜表面微结构,发现ATO纳米粒子的加入,使得微米级乳突表面及乳突之间布满纳米级小凸起,这种微米结构和纳米结构相结合的二阶结构,与天然荷叶表面极其相似,是引起隔热薄膜表面超疏水的主要原因。研究结果为规模制备半透明隔热自清洁聚氨酯薄膜提供了理论和实验依据。     

电化学刻蚀铜箔制备超疏水材料

通过电化学刻蚀和自组装两步法,在铜箔表面成功制备了一层超疏水薄膜。薄膜表面与水的接触角可达到160°。用扫描电镜对超疏水表面进行了表征分析。扫描电镜对铜箔表面观察显示,该表面存在微米-纳米尺度的双层复合结构:底层为均匀分布的沟壑状凹槽,在其表面分布了类草坪状的氧化铜纳米颗粒。研究显示双层的微纳米复合结构是在铜箔表面形成超疏水的关键因素。     

Tracking free volume changes in bisphenol-a based polycarbonate sheets after treatment with liquid acetone

Free volume properties, size and distribution, in the bisphenol-a based polycarbonate (PC) sheets were investigated as a function of the treatment duration by liquid acetone using the positron annihilation lifetime (PAL) spectroscopy. Along with increasing the PC treatment duration, the free volume sizes decreased and the holes-distribution broadened, which in turns led to the polymer crystallization induction. From the PAL and WAXD data, it has been confirmed that the crystallization capability of the amorphous PC tremendously enhanced, with a rapid increase of the PC crystallinity along with increasing the treatment duration by liquid acetone. These findings were further confirmed by the surface chemistry and topography characterization techniques which revealed the formation of crystalline structure after liquid acetone treatment. The solvent-induced crystallization of PC sheets promoted restrictions to the infrared induced molecular vibrations the surface functional groups which was reflected as drop in peaks intensities and shift of the carbonyl peak of the Fourier transform infrared (FTIR) spectrum.     

Surface and wetting characteristics of textured bisphenol‐A based polycarbonate surfaces: Acetone‐induced crystallization texturing methods

Polycarbonate (PC) sheet is a promising material for facile patterning to induce hydrophobic self‐cleaning and dust repelling properties for photovoltaic panels’ protection. An investigation to texture PC sheet surfaces to develop a self‐cleaning structure using solvent induced‐crystallization is carried out using acetone. Acetone is applied in both liquid and vapor states to generate a hierarchically structured surface that would improve its contacts angle and therefore improve hydrophobicity. The surface texture is investigated and characterized using atomic force microscopy, contact angle technique (Goniometer), optical microscopy, ultraviolet‐visible spectroscopy (UV–vis) and Fourier transform infrared spectroscopy. The findings revealed that the liquid acetone‐induced crystallization of PC surface leads to a hierarchal and hydrophobic surface with an average contact angle of 135° and average transmittance <2%. However, the acetone vapor induced‐crystallization results in a slightly hydrophilic hierarchal textured surface with high transmittance; in which case, average contact angle of 89° and average transmittance of 69% are achieved. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43074.     

Solvent‐induced crystallization of a polycarbonate surface and texture copying by polydimethylsiloxane for improved surface hydrophobicity

The influence of the immersion period on the crystallization of polycarbonate (PC) was investigated, and the resulting texture configurations of the crystal structures were reconstructed with polydimethylsiloxane (PDMS). Analytical tools, including optical microscopy, scanning electron microscopy, atomic force microscopy, X‐ray diffraction, the sessile drop technique, Fourier transform infrared spectroscopy, microtribometry, and ultraviolet–visible spectrophotometry, were used to characterize crystallized PC and PDMS surfaces. We found that the crystallized PC surface possessed microsize/nanosize spherulites, voids, and fibrils, and the increasing immersion period increased the texture height and spherulite concentration at the surface. The residual stress in the crystallized PC wafer was compressive, and it was on the order of ?30 MPa. The friction coefficient of the crystallized PC surface remained lower than that of the as‐received PC wafer, and the increase in the immersion period lowered the friction coefficient. The crystallized PC surface demonstrated superhydrophobic characteristics, and the maximum contact angle occurred with 6 min of immersion. The PDMS exactly reconstructed the texture of the crystallized PC surface, except those of the nanofibrils and subnanofibrils. The droplet contact angle attained a higher values for the PDMS replicated surfaces than for those corresponding to the crystallized PC wafer. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43467.     

Novel superhydrophobic top coating on surface modified PVC-coated fabric

A superhydrophobic surface was created on poly(vinylchloride)-coated architectural fabric using spray coating method. Dispersions of nanoparticles and a flourochemical were prepared as top coating solutions. After spray-dry-cure process, contact angle, sliding (tilt) angle, 3 M water repellency test and surface morphology were compared between uncoated and top coated PVC surfaces. The results indicated that a specific nano-TiO₂ dispersion top coating produced a superhydrophobic layer on the top of the PVC surface with high contact angle (150°) and very low sliding angle (2°). Combination of two major requirements, the magnified of the degree of roughness and low surface energy, created self-cleaning effect on the PVC surface. Abrasion fastness of superhydrophobic top coating was improved by surface oxidation via UV–ozone surface treatments. Spectroscopic analysis demonstrated that formation of oxygenated functional groups has improved PVC wettability and adhesion. Results of artificial weathering test indicated no change in superhydrophobicity of top coated PVC.     

High stability superhydrophobic glass-ceramic surface with micro–nano hierarchical structure

Inspired by the surface structure of lotus leaves, micro–nano hierarchical surface structures have been widely used for designing superhydrophobic surfaces. However, the conventionally designed superhydrophobic surface structures are fragile. In this study, a layer of micron-sized mullite whiskers was grown using molten salt on the surface of BaAl₂Si₂O₈ (BAS) glass ceramics. Subsquently, SiO₂ nanoparticles modified with 1H,1H,2H,2H-perfluorodecyltriethoxysilane were sprayed onto the whisker layer to form a superhydrophobic surface. The nanoparticles exhibit superhydrophobicity, which is protected by the whisker layer containing pores and bulges. This prohibits direct contact between the nanoparticles and external objects. Contact and rolling angle tests indicated that the surface contact angle of the micro–nano hierarchical structure is 158° and the rolling angle is less than 10°. The stability of the superhydrophobic surface was tested through ultraviolet light, long-time immersion in solutions with various pH values, water scouring, and sandpaper abrasion. The results showed that the contact angle is greater than 150°. This study is expected to provide a simple and effective method for fabricating superhydrophobic surfaces on ceramics on a large scale.     

Single-step prepared hybrid ZnO/CuO nanopowders for water repellent and corrosion resistant coatings

In this study, ZnO/CuO hybrid hydrophobic nanopowders were synthesized using a common single-step chemical precipitation route without using modifiers. Influence of initial ZnO:CuO precursor concentrations and alkaline agent type on the wettability behavior of the prepared samples were investigated. Wettability properties of the prepared samples were assessed by measuring the water contact angle and contact angle hysteresis values. Fourier transform infrared spectra, scanning electron microscope micrographs and X-ray diffraction patterns were applied to identify the surface chemistry and morphological features. Scanning electron microscope images of the synthesized ZnO/CuO nanocomposites indicated flower-like morphologies containing plenty of nano-needles, -rods, and -sheets with thicknesses lower than 90 nm. The sample prepared under the optimum conditions was superhydrophobic having water contact angle and contact angle hysteresis of 162.6°±1 and 2°, respectively. It was applied to coat the surface of stainless steel meshes by spray deposition method. The resultant superhydrophobic surface exhibited excellent self-cleaning (water repellency) property and a suitable stabilities under the ambient and saline solution (NaCl, 3.5%) media. Additionally, electrochemical corrosion tests confirmed that the corrosion resistance of the fabricated ZnO–CuO coating was higher than the initial bare mesh.     

Preparation of PVDF/PVP core–shell nanofibers mats via homogeneous electrospinning

The polyvinylpyrrolidone (PVP)/poly(vinylidene fluoride) (PVDF) core–shell nanofiber mats with superhydrophobic surface have been prepared via electrospinning its homogeneous blending solutions, and the formation of the core–shell structure was achieved by the thermal induced phase separation assisted with the low surface tension of PVDF. The electrospinnability of the blending solutions was also investigated by varying the blending ratio of the PVP and PVDF, and it enhanced with the increase of PVP content. SEM and TEM results showed that the fibers size was varied in the range of 100 nm–600 nm with smooth surface and core–shell structure. The composition of the shell layer was determined by the XPS analysis, and further confirmed by water contact angle (WCA) testing. As the fraction of PVDF exceeding PVP in the electrospinning solutions, the nanofiber mats showed superhydrophobic property with the WCA above 120°. It indicated that the PVDF was concentrated in the shell layer of the fibers. X-Ray diffraction (XRD) and attenuated total reflection infrared spectroscopy (ATR-IR) analysis indicated that the PVDF was aggregated with the β-phase crystallite as dominant crystallite. The nanofiber mats with the gas breathability and watertightness ability due to the porous structure and superhydrophobic would be potential applied in wound healing.     

自组装法制备PVDF-SiO2/PVSQ超疏水复合膜及膜蒸馏抗污染性能

采用乙烯基三甲氧基硅烷(VTMOS)对SiO₂疏水改性,通过自组装法,将改性SiO₂接枝在商业PVDF(聚偏氟乙烯)膜表面,使其表面达到超疏水。利用场发射电子显微镜、红外光谱仪、接触角测量仪及毛细流孔径分析仪等仪器对改性前后膜的表面形貌、化学组成、接触角及孔径变化等性能参数进行表征。结果表明,VTMOS不仅对SiO₂疏水改性,还通过自身的水解缩聚反应,生成了规整圆球状的聚乙烯基倍半硅氧烷(PVSQ)微粒,纳米级SiO₂分布于微米级PVSQ表面,在改性膜表面构造了多层次微/纳米粗糙表面,在低表面能疏水基团乙烯基和甲氧基的共同作用下,成功实现了超疏水改性,改性膜水接触角达到159.5°,滚动角降至8.1°。以NaCl、HA和CaCl₂混合溶液为进料液,对商业PVDF膜和改性膜进行了长期直接接触式膜蒸馏(DCMD)实验,探究其抗污染性能。结果表明,改性膜适用于长期DCMD实验,并表现出比商业PVDF膜更稳定的通量,截盐率始终大于99.99%,具有良好的稳定性和抗污染性能。     

Facile creation of superhydrophobic surface with fluorine–silicon polymer under ambient atmosphere

A fluorine?Csilicon polymer of poly(styrene-co-1H,1H,2H,2H-perfluorooctyl methacrylate-co-vinyltriethoxysilane) (PSFV) was synthesized by bulk polymerization, and superhydrophobic surfaces were subsequently fabricated utilizing phase separation technique in one step by casting PSFV copolymer solution under ambient atmosphere. The PSFV copolymer was dissolved in tetrahydrofuran (THF), and then ethanol was added into the solution to induce phase separation. The surface morphologies of the copolymer films were controlled by the degree of phase separation, which could be tuned easily by the ethanol/THF volume ratio and the solution??s initial concentration. Scanning electron microscopy observations indicated that the superhydrophobic copolymer film had a rough surface with a binary hierarchical structure. A brief explanation of the formation of the special microstructure was put forward. The water contact angle and sliding angle of the superhydrophobic PSFV surface were measured as 162° and 4°, respectively. The simplicity of the operation??s process might make the superhydrophobic surface potentially useful in a variety of applications.     

Fabrication of flower clusters-like superhydrophobic surface via a UV curable coating of ODA and V-PDMS

In this work, a flower clusters-like superhydrophobic surface was fabricated via an ultraviolet (UV) curable coating of octadecylamine (ODA) and vinyl-terminated polydimethylsiloxane (V-PDMS). ODA self-assembled into many flower clusters-like structures on the surface of the coating, increasing the roughness of the coating surface without additional nanoparticles. V-PDMS formed a highly crosslinked network under a UV lamp, which would be helpful for a robust superhydrophobic surface. The obtained PDMS/ODA fabric showed water contact angle of 161° and sliding angle of 5°. The durability of the superhydrophobic surface was tested by water impacting, tube brush scrubbing, knife scratching, hand twisting, finger pressing, tape adhesion, abrasion, continuous rinsing, and chemical conditions. The experimental results indicated that the superhydrophobic surface have good durability for long service life. Moreover, the PDMS/ODA fabric could selectively absorb oils from water with good separation performance. This work will provide a facile, low cost, and versatile method to prepare superhydrophobic surfaces, and enhance their efficiency of oil–water separation. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48210.