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Feng Sun Jinren Lu Yuhong Wang Jie Xiong Congjie Gao Jia Xu 《Frontiers of Chemical Science and Engineering》2021,15(1):109-117
Surface engineering with polydopamine coatings has been considered a promising surface functionalisation tool.However,it is difficult to control the self-polymerisation for polydopamine formation,which usually causes severe interparticle aggregation.In this study,polydopamine self-polymerisation was controlled by adjusting its reducing environment using a reductant(NaBH4)to fabricate mixed cellulose ester(MCE)/polydopamine membranes.An oxidising environment using NaIO4 was additionally tested as the control.The results showed that a thin polydopamine coating with small polydopamine particles was formed on the skeleton frameworks of the MCE membrane with NaBH4,and the self-polymerisation rate was suppressed.The polydopamine coating formed in the reducing environment facilitated excellent water transport performance with a water permeance of approximately 400 L·m?2·h?1·bar?1 as well as efficient organic foulant removal with a bovine serum albumin rejection of approximately 90%.In addition,the polydopamine coating with NaBH4 exhibited both excellent chemical stability and anti-microbial activity,demonstrating the contribution of the reducing environment to the performance of the MCE/polydopamine membranes.It shows significant potential for use in water purification. 相似文献
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《Ceramics International》2023,49(13):21335-21345
Multi-component and a large number of non-homogeneous interface absorbers have been proven to be the preferred choice of electromagnetic wave (EMW) absorption materials. Herein, hollow porous Ni@SiC nanospheres (HPNS) were successfully constructed by combining a carbothermal reduction preparation strategy and subsequent electroless plating process. The heterogeneous dielectric/magnetic multi-component benefit to excellent EMW absorption properties through forming multiple polarizations, dielectric loss, and magnetic loss effects. Particularly, the HPNS at the optimal ratio with a low filler loading of 20 wt% exhibits the minimum reflection loss (RLmin) value of −62.39 dB at 13.28 GHz and the maximum effective absorption bandwidth (EABmax) is up to 5.36 GHz (12.64–18 GHz), and the corresponding thin matching thicknesses are 1.96 mm and 1.80 mm, respectively. Furthermore, the maximum radar cross section (RCS) reduction of HPNS over PEC reaches 26.02 dB m2 (1.96 mm) under far-field conditions, which means that the prepared HPNS is extraordinarily promising for practical applications. This work guides the preparation of high-performance EMW absorbers as well as radar stealth materials. 相似文献
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采用空间插值和营养指数方程相结合的方法,对锦州湾海域海水富营养化状态进行评价.选择反距离权重(IDW)、径向基函数(RBF)和普通克里金(OK)三种插值方法及相应的关键参数,对2009年8月份锦州湾附近表层海水的高锰酸盐指数(COD)、无机氮(DIN)和无机磷(DIP)指标进行空间插值,通过交叉验证筛选出精度最高的插值方法.结果表明:(1)从插值精度上看,除了RBF法的薄盘样条(TPS)函数精度较低外,其余方法精度差别不显著;(2)从等值线图对空间变化趋势的表现效果上来看,OK法效果较好.最后利用OK法所得的插值结果评价锦州湾海水的富营养化状态,得出营养指数E≥1的海域面积占调查海域的2.4%,与传统的评价方法相比,所绘出的富营养化空间分布图可直观、准确地反映该海域的富营养化状况,为海水水质评价工作提供了新思路. 相似文献
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《Ceramics International》2023,49(13):21287-21295
Porous silicate cement membranes (PSCMs) fabricated by the freeze casting method show great potential to be utilized in seawater pretreatment, fermentation broth separation, and industrial wastewater treatment due to its merit of high-temperature resistance, low-cost, and hierarchically ordered porous structures, while the freeze casting method is complex and time-consuming. In this work, a combination of freeze casting and heat-dry curing was initially applied to generate PSCMs. The preparation periods of PSCMs could be shortened by simplifying preparation processes and reducing curing time. The resulting membranes presented double-layer structures, containing a nucleation zone (N-zone) with dense structures and a stability zone (S-zone) with lamellar pore structures. The X-ray diffraction pattern of membranes displayed the mixed hexagonal and rhombohedral structures. This novel method could save more than half of energy consumption compared with the traditional preparation technology of silicate cement samples. The membranes with a mesopore size of 3.794 nm showed high permeation performance with pure water flux reaching 207.23 L m−2 h−1 under 0.15 MPa and room temperature. The separation efficiency of oil-water was 78.05% under operating pressure of 0.05 MPa. Molecular dynamics simulation was applied to narrate the microscopic process of transformation during heat-dry curing, and obtained a good similarity of consequences between the computational method simulation and experimental operation. 相似文献
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