聚二甲基硅氧烷/微纳米银/聚多巴胺修饰的超疏水海绵的制备和应用

受海洋贝类生物黏附蛋白的启发,在碱性环境下利用多巴胺的自聚合性质,在聚氨酯海绵表面聚合活性聚多巴胺薄层,采用葡萄糖还原银离子进一步沉积微纳米银粒子构筑表面微纳结构,并水解聚二甲基硅氧烷前驱体对表面进行疏水改性,制备出了接触角大于150°的超疏水表面。利用接触角测定、扫描电子显微镜及能量弥散X射线谱和傅里叶红外光谱等技术手段对制备的改性海绵进行了表征,表明微纳米银粒子和硅甲基疏水基团被成功修饰到了海绵表面。改性海绵对有机溶剂和油类物质具有高选择性和高吸收性。吸收的有机溶剂和油类物质的质量能够达到其自身质量的12倍以上。饱和吸收后的海绵仅通过物理挤压即可将吸收的物质回收并使海绵恢复弹性和吸附能力,得到再生。该研究为油水分离和废油回收提供了一种经济、高效、环境友好的方案。     

尼龙表面的超疏水及高度疏油改性

在聚合物表面引入多级粗糙结构并降低表面能可以提高其表面的疏水疏油性. 采用三种不同方法在尼龙6(聚酰胺)表面引入活性基团, 即或将尼龙6材料表面的酰胺键还原成仲胺, 或硅羟基化, 或使用低温等离子体处理得到羟基, 并通过X-射线光电子能谱(XPS)进行验证. 实验结果表明, 表面含有仲胺基团的尼龙6可静电吸附硅球; 而表面含有硅羟基及羟基的尼龙6可原位生长纳米硅层, 再经过3-氨基丙基三甲氧基硅烷(APS)处理可达到硅球吸附的目的. 经比较了不同改性方法对在尼龙6表面构建粗糙结构的影响, 我们认为等离子体处理更利于方便快捷地制备稳定均匀的粗糙结构. 当被全氟十二烷基三氯硅烷(Rf-Si)氟化修饰后, 具有粗糙结构的尼龙6表面均具有超疏水性, 但其疏油性则与表面引入的硅球尺寸密切相关, 如在500～900 nm硅球构建的粗糙表面上, 十六烷烃(3 μL)的静态接触角为140°左右, 滚动角为20°; 而在20～200 nm硅球构建的粗糙表面上, 其静态接触角和滚动角则分别为125°和40°左右. 实验结果还显示, 这类具有一定双疏性的尼龙表面也有较好的抗细菌粘附性.     

A Self‐Assembled Superhydrophobic Electrospun Carbon–Silica Nanofiber Sponge for Selective Removal and Recovery of Oils and Organic Solvents

An oil spill needs timely cleanup before it spreads and poses serious environmental threat to the polluted area. This always requires the cleanup techniques to be efficient and cost‐effective. In this work, a lightweight and compressible sponge made of carbon–silica nanofibers is derived from electrospinning nanotechnology that is low‐cost, versatile, and readily scalable. The fabricated sponge has high porosity (>99 %) and displays ultra‐hydrophobicity and superoleophilicity, thus making it a suitable material as an oil adsorbent. Owing to its high porosity and low density, the sponge is capable of adsorbing oil up to 140 times its own weight with its sorption rate showing solution viscosity dependence. Furthermore, sponge regeneration and oil recovery are feasible by using either cyclic distillation or mechanical squeezing.     

Designing 3D-MoS2 Sponge as Excellent Cocatalysts in Advanced Oxidation Processes for Pollutant Control

3D-MoS₂ can adsorb organic molecules and provide multidimensional electron transport pathways, implying a potential application for environment remediation. Here, we study the degradation of aromatic organics in advanced oxidation processes (AOPs) by a 3D-MoS₂ sponge loaded with MoS₂ nanospheres and graphene oxide (GO). Exposed Mo⁴⁺ active sites on 3D-MoS₂ can significantly improve the concentration and stability of Fe²⁺ in AOPs and keep the Fe³⁺/Fe²⁺ in a stable dynamic cycle, thus effectively promoting the activation of H₂O₂/peroxymonosulfate (PMS). The degradation rate of organic pollutants in the 3D-MoS₂ system is about 50 times higher than without cocatalyst. After a 140 L pilot-scale experiment, it still maintains high efficiency and stable AOPs activity. After 16 days of continuous reaction, the 3D-MoS₂ achieves a degradation rate of 120 mg L⁻¹ antibiotic wastewater up to 97.87 %. The operating cost of treating a ton of wastewater is only US$ 0.33, suggesting huge industrial applications.     

还原氧化石墨烯基三聚氰胺海绵的制备与吸附性能

以天然石墨为原料,用Hummers法和超声剥离法制备了氧化石墨烯(GO).将氧化石墨烯浸渍,涂覆于三聚氰胺海绵表面,在线还原制得还原氧化石墨烯基三聚氰胺海绵(RGOME).通过扫描电子显微镜(SEM)、傅里叶变换红外光谱(FTIR)仪及光学接触角测定仪等分析了RGOME的结构,考察了RGOME对多种油品的吸附性能,并对其油水选择吸附性能和循环使用性能进行了研究.结果表明,RGOME具有疏水超亲油性,对油品的吸附量达到56~127 g/g,可用Bangham方程描述RGOME对甲苯和煤油的吸附动力学过程;在选择吸附过程中,油品浓度急剧降低,吸附量不断升高,分离效率达到74.49%,可较好地实现油水分离;吸附油品的RGOME经脱附可多次循环使用.     

Bioinspired,Cysteamine‐Catalyzed Co‐Silicification of (1 H, 1 H, 2 H, 2 H‐Perfluorooctyl)triethoxysilane and Tetraethyl Orthosilicate: Formation of Superhydrophobic Surfaces

Bioinspired silicification attracts a great deal of interest because of its physiologically relevant, mild conditions for hydrolysis and condensation of silica precursors, which makes the bioinspired approach superior to the conventional sol–gel process, particularly when dealing with biological entities. However, the morphological control of silica structures with incorporation of functional groups in the bioinspired silicilication has been unexplored. In this work, we co‐silicificated (1 H, 1 H, 2 H, 2 H‐perfluorooctyl)triethoxysilane and tetraethyl orthosilicate to investigate the morphological evolution of fluorinated silica structures in the cetyltrimethylammonium bromide‐mediated, cysteamine‐catalyzed silicification. The generated micrometer‐long worm‐like and spherical silica structures display superhydrophobicity after film formation. Interestingly, the measurement of dynamic water contact angles shows that the morphological difference leads to a different wetting state, either the self‐cleaning or the pinning state of the superhydrophobic surface.     

Designing 3D‐MoS2 Sponge as Excellent Cocatalysts in Advanced Oxidation Processes for Pollutant Control

3D‐MoS₂ can adsorb organic molecules and provide multidimensional electron transport pathways, implying a potential application for environment remediation. Here, we study the degradation of aromatic organics in advanced oxidation processes (AOPs) by a 3D‐MoS₂ sponge loaded with MoS₂ nanospheres and graphene oxide (GO). Exposed Mo⁴⁺ active sites on 3D‐MoS₂ can significantly improve the concentration and stability of Fe²⁺ in AOPs and keep the Fe³⁺/Fe²⁺ in a stable dynamic cycle, thus effectively promoting the activation of H₂O₂/peroxymonosulfate (PMS). The degradation rate of organic pollutants in the 3D‐MoS₂ system is about 50 times higher than without cocatalyst. After a 140 L pilot‐scale experiment, it still maintains high efficiency and stable AOPs activity. After 16 days of continuous reaction, the 3D‐MoS₂ achieves a degradation rate of 120 mg L^?1 antibiotic wastewater up to 97.87 %. The operating cost of treating a ton of wastewater is only US$ 0.33, suggesting huge industrial applications.     

磷杂菲类阻燃剂的合成及其与聚磷酸铵复合膨胀体系对环氧树脂的阻燃性能研究

以9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物(DOPO)、五硫化二磷(P2S5)为原料合成9,10-二氢-9-氧杂-10-磷杂菲-10-硫化物(DOPS),并将DOPS与聚磷酸铵(APP)组成复合阻燃剂,用于环氧树脂(EP)的阻燃改性.通过氧指数(LOI)、垂直燃烧(UL-94)、热失重(TGA)、锥形量热(CONE)和扫描电镜(SEM)等方法对改性后的环氧树脂的阻燃性能和阻燃机理进行了测试和分析.实验结果表明,DOPS/APP阻燃体系对EP具有很好的阻燃性能,且复配阻燃剂的阻燃效果比单一的阻燃剂阻燃效果好;其中,当阻燃剂的总添加量达到30%时即W_(DOPS)=10%、W_(APP)=20%时,阻燃EP复合材料的LOI值可达到29.2%,垂直燃烧等级达到UL-94 V-0级,残炭量可达49.3%.     

Fluorescence Microscopy Visualization of Contacts Between Objects

The area of contact between two objects was detected by using the strong enhancement of the fluorescence of rigidochromic probe molecules attached to one of the surfaces. Confinement of the molecules suppresses nonradiative decay and turns on the fluorescence. The approach is demonstrated by imaging of the contact area of a plastic sphere in contact with a flat glass surface. Our results agree excellently with the prediction of Hertz’s classical theory based on elastic deformation.     

Biomimetic Self-Cleaning Anisotropic Solid Slippery Surface with Excellent Stability and Restoration

Anisotropic slippery surfaces are widely used in anti-fouling, smart control of liquid movement and directional liquid transportation. However, anisotropic slippery liquid-infused porous surfaces (SLIPS) cannot meet the need of practical applications owing to loss and contamination of liquid lubricants. Inspired by solid epicuticular wax on the surface of land plant leaves, we herein report a type of biomimetic anisotropic solid slippery surface (ASSS) based on paraffin wax-incorporated paper with directional micro-grooves. This ASSS material shows anisotropic sliding behavior for liquid droplets with different surface tensions. It is demonstrated to be of excellent stability compared with SLIPS as the solid lubricant cannot be lost and stain the contacting surfaces. It also exhibits outstanding acid and alkali corrosion resistance and restoration capability upon physical damage. Both hydrophilic and hydrophobic contaminants on our ASSS can be self-cleaned by using only water droplets. Our ASSS extends the fabrication of new slippery materials and overcomes some drawbacks of SLIPS.     

Flame retardancy and heat resistance of phenol-biphenylene-type epoxy resin compound modified with benzoguanamine

The flame retardancy and heat resistance of a phenol-biphenylene-type epoxy resin compound, which forms a self-extinguishing network structure, were increased by the inclusion of a benzoguanamine-modified phenol biphenylene resin. The benzoguanamine-modified phenol biphenylene resin contains a benzoguanamine unit to release non-flammable nitrogen substances during ignition and to increase the resin's reactivity toward epoxy resins, and biphenylene units to keep the resin's thermal degradation and water resistance. The addition of the benzoguanamine-modified phenol biphenylene resin in the epoxy resin compound improved the epoxy resin compound's flame retardancy and heat resistance, and also increased its glass transition temperature while maintaining its water resistance and mechanical properties. Copyright © 2003 John Wiley & Sons, Ltd.     

Selective Transportation of Microdroplets Assisted by a Superhydrophobic Surface with pH‐Responsive Adhesion

We report a new strategy to realize the selective transportation of microdroplets assisted by a superhydrophobic surface with pH‐responsive adhesion. On the surface, only basic microdroplets can be pinned and acidic or neutral microdroplets can easily roll off. Therefore, by using the surface as a “mechanical hand”, microdroplets can be transported selectively according to one’s requirements by simply controlling the pH of the solution. The special ability of the surface to achieve selective transportation is ascribed to the following two reasons: 1) superhydrophobicity, which can avoid the wetting problem, and 2) pH‐responsive adhesion, which results from the combined effect of chemical variation of the carboxylic acid group and microstructures on the surface. Furthermore, we also demonstrated a process of selective transportation of microdroplets for applications in droplet‐based microreactors through our surface. The results reported herein advance a new method to realize the selective transportation of microdroplets and we believe that this method could potentially be used in a wide range of applications, such as biomolecular detection and transportation in biochips.     

Fluorescent Probes for Pd2+ Detection by Allylidene–Hydrazone Ligands with Excellent Selectivity and Large Fluorescence Enhancement

Because palladium is widely used in various catalysts and converters, which results in a high level of contamination of water systems and the soil by residual palladium, there is an urgent need for Pd²⁺‐sensitive and ‐selective probes. Based on the special affinity of Pd²⁺ to conjugated double‐bond ligands, two fluorescence probes ( RPd2 and RPd3 ) that contain conjugated allylidene‐hydrazone ligands that link to colorless rhodamine‐spirolactam have been developed. The results show that conjugated allylidene‐hydrazones have a much better affinity toward Pd²⁺, and consequently provide the probes with more acute color change and fluorescence enhancement (≈170‐fold), and better selectivity over other metal ions (especially platinum‐group elements, or PGEs) than the unconjugated allyl‐hydrazine. With richer electron density and a more suitable stereo effect in the allylidene‐hydrazone group, RPd2 displays the best specificity toward Pd²⁺ and affords convenient detection by the naked eye. Its potential application for Pd²⁺‐contaminated water and soil‐sample analysis is revealed by proof‐of‐concept experiments.     

Flame retardancy and thermal degradation of intumescent flame retardant polypropylene with MP/TPMP

The performances of the novel intumescent flame retardant (IFR) polypropylene (PP) composites containing melamine phosphate (MP) and tris(1‐oxo‐2,6,7‐trioxa‐1‐phosphabicyclo[2,2,2]methylene‐4)phosphate (TPMP) were investigated. The flame retardancy of IFR‐PP system was characterized by limiting oxygen index (LOI) and UL 94 and cone calorimeter. The morphology of the char obtained after cone calorimeter testing was studied by scanning electron microscopy (SEM). The thermal oxidative degradation (TOD) of the composites was investigated by using thermogravimetric analysis (TGA) and real‐time Fourier transform infrared spectroscopy (RT‐FTIR). Compared with the PP/ TPMP or PP/ MP binary composite, at the same addition level, the LOI values of the PP/MP/TPMP ternary composites increase and reach V‐0 at the suitable MP/TPMP ratio. The results of TGA and RT‐FTIR showed the existence of the interaction between IFR and PP. Copyright © 2008 John Wiley & Sons, Ltd.