In situ fabrication dynamic carbon fabrics membrane with tunable wettability for selective oil–water separation

Xuejie Yue,Tao Zhang,Dongya Yang,Fengxian Qiu,Yao zhu,Jiasheng Fang 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.61 No.-

Achieving reversible wetting properties of separation membrane for on-demand separate oil/water mixture remains challenging, especially for the oil/water mixtures with complex impurities. Herein, hierarchical porous dynamic separation membranes involving primary fiber membrane and secondary nanostructures are fabricated by in situ growth ZnO nanowires on the surface of carbon fibers. Based on the effect of oxygen-related defects of ZnO nanowires coating, the as-fabricated dynamic separation membrane is capable of switching wetting property between high-hydrophobicity and superhydrophilicity via simply annealing alternatively under vacuum and air environment, achieving the switching between oil-removing mode and water-removing mode according to the type of oil/water mixtures. Moreover, the dynamic separation membrane can be extended to separate the oil/water mixtures containing suspended solids using the reconstruction of ZnO dynamic coating. Through removing the ZnO dynamic coating via soaking the clogged membrane in the hydrochloric acid–ethanol and refabricating the ZnO-dynamic coating, the membrane blocked by impurities could be readily re-formed, which effectively expand its scope of application and enhance its anti-fouling property. This work not only provides a simple and on-demand solution for pure oily wastewater, but also extends the separation membrane to separate oil/water mixtures containing suspended solids.

Hierarchical Porous BiOCl/LDHs Composites Templated from Cotton Fibers for Efficient Removal of Dyes from Aqueous Solution

Tao Zhang,Xinbin Nie,Xuejie Yue,Dongya Yang,Yuting Dai,Fengxian Qiu 한국섬유공학회 2018 Fibers and polymers Vol.19 No.3

Hierarchically structured BiOCl/LDHs composites with well-developed porosity and high surface area have been prepared by an in situ growth of BiOCl on the surfaces LDHs fibers, and their adsorption capacities and photocatalytic activities are investigated by using methylene blue (MB) as model pollutants. The results indicate that the BiOCl/LDHs composites possess high surface area up to 126.2 m2/g. The as-prepared BiOCl/LDHs composites exhibited higher adsorptive ability and improved photocatalytic activity compared to bare BiOCl particles and LDHs fibers based on the removal of MB in aqueous solution, showing that BiOCl/LDHs composites can be used as efficient environmentally friendly materials for dye wastewater treatment.

Preparation of Carbon Nanotubes/Polyurethane Hybrids as a Synergistic Absorbent for Efficient Oil/Water Separation

Tao Zhang,Bin Gu,Fengxian Qiu,Xiaoming Peng,Xuejie Yue,Dongya Yang 한국섬유공학회 2018 Fibers and polymers Vol.19 No.10

Polyurethane (PU) hybrid materials have attracted a great deal of attention as oil-absorbents in oil/water separation because they combine the surface properties of nanomaterials and the excellent absorption properties of PU. Herein, we report a facile two-step process to synthesize the oil-absorbing hybrid materials by integrating carbon nanotubes (CNTs) into porous PU foam architectures. First, the multi-walled carbon nanotubes (MWCNTs) were modified by oxidation in binary H2SO4-HNO3 mixed acid, followed by grafting the silane coupling agent (KH 570) on the on surfaces of MWCNTs. Then, the MWCNTs/PU hybrid materials were synthesized using isocyanate and polyether polyol as monomers for polymerization and surface modified MWCNTs as inorganic components. The physical and chemical properties of hybrid materials were validated by XRD, TEM, SEM, N2 sorption and contact angle analysis. The surface grafted MWCNTs possess superhydrophobic properties with the maximum water contact angle of 153 o. The SEM results indicate that the WCNTs/PU hybrid materials consisted of spherical structures with microscale holes, which can separate oils from oil/water mixtures with high absorption properties and high selectivity. Effects of the various MWCNTs contents on the oil absorption behavior of the WCNTs/PU hybrid materials were investigated. The results show that the modified MWCNTs significantly improves the oil absorption properties with the optimal MWCNTs content of 3 %. By combining the structural features of WCNTs and PU foams, the hybrid materials not only exhibit excellent absorption properties for various types of oils and organic solvents, but also show excellent oil recoverability and absorbent regenerability. The as-synthesized WCNTs/PU hybrid have significant potential as oil absorbents for efficient separation of oils and organic solvents from water.

Circuit Module Design of High-Voltage Side for Optical Current Transformer

Ying Zhang,Shenghui Wang,Xuejie Wang,Lei Qi 보안공학연구지원센터 2016 International Journal of Smart Home Vol.10 No.1

The Field Programmable Gate Array (FPGA) technology has been used for designing the signal processing circuit of A/D device, CRE code and Manchester module of high-voltage side for optical current transformer in this paper. The A/D controlling module, CRC code module, Manchester encoding module and the storage in FPGA has been designed and simulated. The signal processing circuit design program of high-voltage side for optical current transformer in this paper has been proved from the simulating results and can meet the requirements of optical current transformer on communication of data, which is rapid and reliability.

Precipitating tunable-emission CsPb(Cl/Br)3 QDs in boro-germanate glass for wide-color-gamut liquid crystal displays

Xiaoliang Pang,Xuejie Zhang,Bingfu Lei,Haoran Zhang 한국정보디스플레이학회 2019 Journal of information display Vol.20 No.4

Embedding CsPbX3 (X = Cl, Br, I) perovskites QDs in inorganic glass matrix via in-situ crystallization has been regarded as a feasible strategy to improve their stability against water, heat, and light irradiation. However, the tunable-emission range of these CsPbX3-nanocrystals-embedded glasses is still narrow, insufficient to cover a wide color gamut. Herein, a simple synthetic method was developed in this study to obtain the tunable-emission CsPb(Cl/Br)3 quantum dots (QDs) in boro-germanate glass (CsPb(Cl/Br)3 QDs@glass) by controlling the molar ratio of PbBr2/PbCl2. With the increase of the PbBr2 concentration from 1.6 to 3.2 mol%, the emission wavelength of CsPb(Cl/Br)3 QDs@glasses can be shifted from 448 to 485 nm, and the corresponding photoluminescence quantum yield (PLQY) increases from 0.61 to 24.43%. In addition, the CsPb(Cl/Br)3 QDs@glass exhibits impressing promotion of thermal stability, photostability, and water resistance due to the excellent protective function of the glass matrix. As a proof-of-concept experiment, a LED device was fabricated by employing the optimal CsPb(Cl/Br)3 QDs@glass with a commercial 375nmUVchip, yielding an intense cyan light. All the results indicate that the investigated CsPb(Cl/Br)3 QDs@glasses may find promising applications as color convertors in wide-color-gamut liquid crystal displays (LCDs).

Hierarchical Al2O3/SiO2 fiber membrane with reversible wettability for on-demand oil/water separation

Zhangdi Li,Tianhui Shi,Tao Zhang,Qing Guo,Fengxian Qiu,Xuejie Yue,Dongya Yang 한국화학공학회 2019 Korean Journal of Chemical Engineering Vol.36 No.1

This work presents an effective method of fabricating hierarchical Al2O3/SiO2 fiber membrane with reversible wettability for on-demand oil/water separation. In this strategy, the superhydrophilic/underwater superoleophobic surfaces are fabricated by in-situ growing hierarchical Al2O3 nanosheets on the SiO2 fiber surfaces that can be used as water-removing materials for oil/water separation. Then, the superhydrophobic/oleophilic surfaces are obtained by surface chemical modification with sodium laurate, which can be used as oil-removing materials for oil/water separation. Interestingly, the reversible wettability transformation of Al2O3/SiO2 fiber membrane can be controlled by the annealing and modification treatment alternately. The as-prepared Al2O3/SiO2 fiber membrane, combining the advantages and overcoming disadvantages of two modes, achieves reversible wettability transitions and on-demand oil/water separation. In addition, the Al2O3/SiO2 fiber membrane shows a significant chemical stability and super-wettability even after five annealing and surface modification cycles, indicating its excellent durability. The separation efficiency in both oil-removing mode and water-removing mode is over 95% for various oil/water mixtures through multiple recycle separation processes. This work not only provides a simple and cost-effective method to fabricate separation membrane with reversible wettability, but also shows great potential in remediation of large-scale oil spillage or organic solvents discharge at different environmental conditions.

Microalgal and cyanobacterial strains used for the bio sorption of copper ions from soil and wastewater and their relative study

Shah Zada,Saleem Raza,Sikandar Khan,Arshad Iqbal,Zhang Kai,Aftab Ahmad,Midrar Ullah,Mohib Kakar,Pengcheng Fu,Haifeng Dong,Zhang Xueji 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.105 No.-

Heavy metals and other organic pollutants are the hazardous materials causing soil and water pollution,hence, bioremediation of these components is a matter of concern for environmental biotechnologists. Twenty one microalgal and cyanobacterial strains were evaluated for removal of copper from aqueoussolutions and soil containing 10 ppm copper. 5 out of 21 strains have shown comparatively higher toleranceto copper stress. The biosorption capabilities of all the five strains were assessed using techniqueslike ultraviolet (UV) spectrophotometers, scanning electron microscope (SEM), inductively coupledplasma mass spectrometry (ICP-MS), and confocal Microscopy. It was found that the five selected strainscould grow normally upon incubating with 20 ppm of Cu. Copper removal efficiencies of these microalgae(S. obliquus, A. braunii, C. fusca, L. JSC-1 and C. saccharophila in water were 99.9, 99.3, 97, 96.7, and 96%,while for soil was 73, 75, 71, 70, 68%, respectively. A minor leakage of nucleic acid and protein weredetected with time. Furthermore, no any visible morphological changes were observed after six daysof treatment, while minor changes were noticed after 12 days in water, and severe morphological deformationsoccurred after 24 days of bioremediation in soil. Our findings reveal that the selected microalgalstrains have high potential for Cu bioremediation at certain concentration for 12 days exposure fromwater and 24 from soil.