Hydrogen sensing by RGB investigation of gasochromic coloration of MoO3/Pd-coated polyester fabrics

Recently, colorimetric sensors capable of detecting explosive and toxic molecules have attracted much attention for applications in health and environmental monitoring. Here, we demonstrate the detection of hydrogen gas using gasochromic fabrics and evaluate their performance with a commercial RGB color sensor module. For this purpose, first a thin Pd film was sputter deposited onto the polyester fabric and then amorphous MoO₃ films (several microns) were deposited by RF reactive magnetrons in various O₂/Ar ratios (from 2.5 to 12.5 O₂). Field emission scanning electron microscope (FESEM) identified the morphological changes of the surface at each coating step and showed that the fibrous structure of the fabrics was preserved after coating of the films, which is suitable for better gas adsorption. Exposure to hydrogen caused the obtained MoO₃/Pd/polyester samples to turn blue-gray at room temperature and the UV–Vis spectra showed an increase in optical absorption. Their sensitivity was evaluated in the presence of different H₂ concentrations from 250 to 10,000 ppm by recording the time variation of color difference (RGB Euclidean distance). A significant correlation was found between absorption spectrum and RGB analysis with respect to oxygen content. The color variation showed a linear behavior with respect to hydrogen concentration for all samples. Response and recovery times, reversibility and reproducibility in the presence of hydrogen gas were also evaluated using the RGB readout data. Overall, the RGB module optimally depicts the sensing characteristics of the gasochromic fabrics in terms of reversibility, sensitivity and reproducibility, which may contribute to their commercial development.     

基于LS-SVM棉针织物轧烘轧蒸染色工艺的预测模型

为优化活性染料对棉针织物的轧烘轧蒸染色工艺,基于最小二乘支持向量机(LS-SVM),以氯化钠质量浓度、碳酸钠质量浓度、烘干时间和汽蒸时间作为预测模型的输入变量,染色织物K/S值作为输出变量,建立了多因素模型并进行预测。结果表明,织物实验K/S值和模型预测值的相关系数高达0.99996,平均相对误差小于0.5%,说明该模型具有较高的精度,该建模方法可用于染色织物K/S值的预测,可以用于棉针织物轧烘轧蒸染色工艺的预测和优化。     

Advanced Surface of Fibrous Activated Carbon Immobilized with FeO/TiO2 for Photocatalytic Evolution of Hydrogen under Visible Light

FeO-doped TiO₂ nanoparticle photocatalysts were immobilized onto the surface of fibrous activated carbon (ACF) via a sol-gel process. As an adsorbent and photocatalyst, FeO-TiO₂ on immobilized ACFs (FeO-TiO₂/ACF) greatly improved the photocatalysis rate of hydrogen production as compared with pure TiO₂ and ACF-TiO₂ under UV irradiation and visible light. The addition of ACFs surface significantly reduced the photogenerated pairs of electrons-hole recombination, thereby promoting the photocatalysis action of doped photo-metal oxides of FeO-TiO₂. Co-doping of FeO onto the lattice of the TiO₂ approach can improve the absorption activity of visible light through photo-metal oxide of TiO₂ and further enhance hydrogen production under visible light. The photocatalytic fabrics (FeO-TiO₂/ACF) were effortlessly split out from the experimental solution for re-utilization and exhibited high stability even after five complete regeneration cycles.     

Diffuse reflectance behavior of the printed cotton/nylon blend fabrics treated with zirconium and cerium dioxide and citric acid in near- and short-wave IR radiation spectral ranges

Near- and short-wave IR emission spectra of printed cotton/nylon blend fabrics coated with inorganic compounds in order to tune their diffuse reflectance behavior to the ones with woodland and desert backgrounds are investigated. In this regard, cotton/nylon blend fabrics printed with a four-color digital pattern were used as the substrate, and different concentrations of zirconium and cerium dioxide (ZrO₂ and CeO₂) with and without citric acid as a cross-linker were loaded on these fabrics using the pad-dry-cure method. The diffuse reflectance of the coated fabrics with various concentrations of nanoparticles and a cross-linker was first measured by near-infrared (NIR) diffuse reflectance spectroscopy (DRS). Then, fabrics with an optimum concentration of nanoparticles and appropriate reflectivity profiles similar to woodland and desert were investigated by field emission scanning electron microscopy (FE-SEM), energy-dispersive spectroscopy (EDS), washing, and rubbing fastness properties. In general, NIR and short-wave infrared (SWIR) reflectance of fabrics coated with ZrO₂ and CeO₂ nanoparticles in range of 1% to 1.5% (w/v [%]) was suitable for matching with different environments. According to the findings obtained from the durability test, it was concluded that the washing fastness of the treated fabrics with CeO₂ nanoparticles was excellent in both environments. FE-SEM images of the treated fabrics containing ZrO₂ and CeO₂ indicated that the presence of nanoparticles on the surface of fabrics in woodland patterns was greater than the desert ones. However, the coated fabrics with CeO₂ and citric acid in the woodland pattern have shown better dispersion with a mean particle size of 30 to 60 nm.     

动态调湿控温立体针织物拓扑优化设计

为研发具有优良动态调湿控温性能的立体针织物,采用双股70 dtex(72 f)的DRYARN^®纱线与30 dtex DRYARN^®纱线包覆30 dtex氨纶长丝为原料,提出了立体针织物拓扑优化设计方法。通过优化设计各控温单元的排列方式,使控温单元按V字、Y字等斜向错位排列,然后采用单面提花工艺对织物进行局部拉伸与压褶以形成褶皱片状结构。结果表明:当人体流汗时,褶皱片状结构里层吸收汗滴并转移至面层以快速蒸发,当人体感到寒冷时,内部空气通道储藏静止空气有效控温;所制备织物的保温率均大于54%,具有出色的控温性能,整体液态水分传递能力达到3级以上,液态水动态传递性能良好,同时保持优良的拉伸回复性能,为冬季运动保暖内衣用立体针织物的研发提供了新思路。     

中国古代城市形态肌理的成因探析

该文比较了中外城市规划的不同模式，揭示了中国古代城市是粗放的大街廓及自发生长的街巷相叠加的二元城市形态，进而从控制的难易、商业的发展、财政的投入、管理的体制等四个方面，对封建人治政体所导致的中国城市形态进行了深入探讨。     

持久疏水涂层织物的制备及其油水分离性能研究

以甲基三乙氧基硅烷（ MTES）为原料,采用溶胶 -凝胶法,在 MTES溶胶中引入端羟基聚二甲基硅氧烷（ PDMS-OH）柔性疏水链段,制得聚硅氧烷凝胶,研究了柔性疏水链段对聚硅氧烷凝胶的柔韧性及疏水性的影响;采用浸渍涂覆的方法,在聚酯织物表面负载聚硅氧烷凝胶,固化后制备得到涂层织物。采用红外光谱（ FT-IR）、抗弯模量和水接触角,对聚硅氧烷凝胶及织物涂层的结构、柔韧性、疏水稳定性及其耐久性进行表征。结果表明： PDMS-OH能够大幅提高涂层织物的柔韧性和疏水性,在聚硅氧烷溶胶中,加入 0. 10 mol端羟基含量为 8. 5%的 PDMS-OH时,涂层织物的静态水接触角可达到（ 138±2）°,且具有持久的稳定性;同时,油水分离实验结果表明,制备的涂层织物可以实现以正己烷、苯和苯胺为代表的烷烃、芳香烃类等油水混合物的有效分离。     

Kevlar纤维布/剪切增稠液复合材料制备及防刺性能

采用纳米SiO2和聚乙二醇(PEG200)制备不同SiO2质量浓度的剪切增稠液体(Shear Thickening Fluid,STF),并检测其流变性能;用落锤式冲击实验装置检测纯Kevlar纤维布和经STF浸渍的STF-Kevlar复合纤维布防刺性能。研究结果表明:不同SiO2质量浓度的STF均有剪切增稠现象,随着SiO2质量浓度升高,起始粘度增大,增稠现象越显著,而临界剪切速率基本不变;同层数的STF-Kevlar复合纤维布的防刺性能明显优于纯Kevlar纤维布,防刺性能随SiO2质量浓度的增加而提高。     

针织结构复合材料的应用与发展

介绍了针织结构复合材料应用情况,描述了经编多轴向结构、经编间隔、针织管状与针织异形结构等针织结构复合材料的特点与性能,以及针织结构复合材料在航空航天、能源领域、车船制造、建筑工程、柔性复合材料等领域的应用,展望了针织结构复合材料的发展前景。     

Acoustic properties of sound-absorbing polyester fabrics woven with thick staple and thin draw textured yarn for use in interior decoration

Environmental pollution in our daily life because of noise is an increasing public health concern. We designed and woven with staple- and draw-textured yarns, for sound absorbance purposes. For wefts and warps, two different thicknesses of the thick staple-yarn and thin draw-textured filament yarn were used. The prepared fabrics were classified in porous, medium, and dense, on the basis of their densities and air permeabilities, and the sound absorption coefficients of the fabrics were found to be linearly related to the air permeability. The sound absorption coefficient determined by the impedance tube method was higher for porous fabrics compared with that for dense fabrics in the high frequency region. By the reverberant field method, the sound absorption coefficients for all fabrics were highest in the low frequency region. Porous fabrics exhibited a shorter reverberation time and a higher sound absorption coefficient than dense fabrics owing to their good sound absorption property.