SiO2溶胶/蜡乳液对棉织物的超疏水改性整理

通过乳化的方法制备得到了稳定性良好的棕榈蜡乳液,同时采用溶胶凝胶法以辛基三乙氧基硅烷为前驱体,制得改性SiO2溶胶。随后采用两步法对棉织物表面进行改性,首先用改性SiO2溶胶整理,然后用棕榈蜡乳液与石蜡乳液的复配乳液继续整理。经测试表明,棉织物的水接触角高达166.2°,经过5次水洗和50次摩擦后,棉织物仍具有良好的疏水性能。超疏水棉织物的白度由初始的85.5%降至72.2%,透气性由初始的177.9 mms^-1降至137.2 mms^-1,但几乎不影响其服用性能。其经向强力由初始的605 N提高至634 N,纬向断裂强力由初始的302 N提高至326 N。最后对棉织物的表面形貌、性能变化及超疏水机理进行了深入的探讨。

棉织物表面的超疏水功能改性整理与性能表征

采用新的方法制备超疏水棉织物,突破了传统使用额外纳米粒子构造粗糙表面结构制备超疏水纺织品的局限性。首先采用有机硅树脂在织物表面形成一层疏水性薄膜,然后借助硅树脂的黏附性将十八胺牢固地固着在织物表面,以此达到构造粗糙表面结构和降低织物表面能的目的。实验结果表明,整理后的棉织物与水的接触角高达154.4°±0.6°,经、纬向强力分别下降了6.2%和8.3%,而白度增加了1.3%。棉织物表面经过30次机械摩擦后,其接触角为151.5°±0.4°。最后对改性前后棉织物的表面形貌和超疏水机理进行了深入分析。

Contactless Microwave Detection of Shubnikov–De Haas Oscillations in Three-Dimensional Dirac Semimetal ZrTe_5

We report Shubnikov–de Haas(SdH)oscillations of a three-dimensional(3D) Dirac semimetal candidate of layered material ZrTe_5 single crystals through contactless electron spin resonance(ESR)measurements with the magnetic field up to 1.4 T.The ESR signals manifest remarkably anisotropic characteristics with respect to the direction of the magnetic field,indicating an anisotropic Fermi surface in ZrTe_5.Further experiments demonstrate that the ZrTe_5 single crystals have the signature of massless Dirac fermions with nontrivialBerry phase,key evidence for 3D Dirac/Weyl fermions.Moreover,the onset of quantum oscillation of our ZrTe_5 crystals revealed by the ESR can be derived down to 0.2 T,much smaller than the onset of SdH oscillation determined by conventional magnetoresistance measurements.Therefore,ESR measurement is a powerful tool to study the topologically nontrivial electronic structure in Dirac/Weyl semimetals and other topological materials with low bulk carrier density.

Transport signatures of the topological surface state induced by the size effect in superconductor β-PdBi_(2)

The superconductivity and nontrivial topological electronic state are key hallmarks of topological superconductors.Here,we focus on the transport signals of possible topological surface state in the topological superconductor candidate β-PdBi_(2) nanoflake with a thickness of 21 nm.The resistance demonstrates a semiconductor-metal transition followed by an upturned behavior as the temperature decreases.A large and unsaturated longitudinal magnetoresistance(MR),accompanied by distinct Shubnikov-de Hass oscillation in Hall resistance,is observed.An analysis of Hall resistance reveals that the carriers present the characteristics of relativistic particles with small effective mass and extremely high mobility.The angle-dependent quantum oscillations demonstrate a two-dimensional Fermi surface topology.A giant anisotropic MR as large as 98%is detected when rotating the magnetic field.These results provide the possible transport signals of a nontrivial topological electronic state,establishing a further understanding of the topological properties of the low-dimensional topological superconductor candidate β-PdBi_(2).

De Haas–van Alphen study on three-dimensional topological semimetal pyrite PtBi2

We present the systematic de Haas–van Alphen(d Hv A) quantum oscillations studies on the recently discovered topological Dirac semimetal pyrite PtBi2 single crystals. Remarkable d Hv A oscillations are emerged at a low field about 1.5 T. From the analyses of the d Hv A oscillations, we extract the high quantum mobilities, light effective masses and phase shift factors for the Dirac fermions in pyrite PtBi2. From the angular dependence of the d Hv A oscillations, we map out the topology of the Fermi surface.Furthermore, we identify two additional oscillation frequencies that are not probed by the Sd H oscillations, which provides us with opportunities to further understand its Fermi surface topology.

Highly integrated smart mountaineering clothing with dual-mode synergistic heating and sensitive sensing for personal thermal management and human health monitoring

The development of multifunctional textiles is an effective strategy to improve the quality of human life.Normal single-mode heaters and strain sensors have been developed,but their low integration leads to multiple devices being installed on the garment,which greatly increases the weight of the garment and thus reduces its wearability.Here,bio-enzymatic polymerization and a simple shaking deposition method were used to prepare poly(3,4-ethylenedioxythiophene)(PEDOT)and copper(Ⅱ)sulfide(CuS)onto the surface of the elastic nylon fabrics,which endowed the fabrics with excellent dual-mode heating properties and sensitive sensing properties,and used to develop highly integrated multifunctional and smart mountaineering clothing.In electro-driven heating mode,low-voltage(6 V)and high-voltage(12 V)heating can be used for joint heat therapy and active rapid deicing,respectively.In photo-driven heating mode,low intensity(0.3 sun)and high intensity(1.5 sun)heating can be used for joint heat therapy and rapid antibacterial,respectively.In addition,the fabric has the ability of dual-mode synergistic heating,and the surface temperature of the fabric can exhibit an ultra-high temperature of 137.9℃ under the external stimulation of 0.3 sun and 12 V.The fabric will greatly enhance the deicing and antibacterial efficiencies under the synergistic effect.This work provides a facile strategy for the fabrication of flexible and highly integrated multifunctional electronic devices,and therefore has great potential for the design and development of all-in-one multifunctional electronic devices such as personal thermal management,soft robotics,and human-computer interaction.