Chi Huang

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Name: 黄驰; Chi Huang

Organization: Wuhan University , China

Department: College of Chemistry and Molecular Sciences

Title: Professor(PhD)

TOPICS

Material Chemistry

Polymer

POSS Polypyrrole Polyacetylene Polypyrrole Polyacetylene

Physical Chemistry

Chemicals
References

Polyurethane–fluoropolymer interpenetrating polymer network membrane for pervaporation recovery of butanol

Co-reporter:Sun Lishui;Hu Mingjie;Feng Bingkun;Ma Yanfei;Liao Jun;Huang Chi

Polymer Bulletin 2017 Volume 74( Issue 6) pp:2331-2347

Publication Date(Web):26 October 2016

DOI:10.1007/s00289-016-1822-0

Hydroxyl terminated polybutadiene (HTPB) based polyurethane (PU)–fluoropolymer interpenetrating polymer network (IPN) membrane was prepared to improve the permeation flux of HTPB based PU for pervaporation recovery of butanol. The IPN was characterized by FTIR, TGA, SEM and WCA. With a separation membrane thickness of 21 μm, the membrane obtained a total flux of 7.03 with a separation factor of 452.6 g/m2h at 70 °C, the permeation flux improved greatly while the separation factor decreased in comparison with HTPB based PU.

Novel phosphorus containing flame retarded RTV silicone rubbers

Co-reporter:Zhishuai He;Mingjie Hu;Haoquan Yuan

Wuhan University Journal of Natural Sciences 2017 Volume 22( Issue 3) pp:185-190

Publication Date(Web):06 May 2017

DOI:10.1007/s11859-017-1233-6

A reactive flame retardant cross-linker (SPTES) was successfully synthesized with dichloropentate and 3-triethoxysilyl-propylamine (APTES) in this research. Then it was further applied into the room temperature vulcanized (RTV) silicone rubber to prepare novel flame retarded RTV silicone rubbers containing phosphorus. The structure, thermal degradation stability, mechanical properties and flammability properties of the novel RTV silicone rubbers were tested and characterized. The results showed that the mechanical and flammability properties of the RTV silicone rubber simultaneously got better with the SPTES content increased. Compared with the sample prepared by APTES, the tensile strength of novel RTV silicone rubbers increased from 0.12 MPa to 0.38 MPa and the limit oxygen index increased from 19.8 to 23.5.

A convenient way to reduce the hysteresis width of VO2(M) nanomaterials

Co-reporter:Xiaofang Li;Siwei Zhang;Liuqing Yang;Xiongjian Li;Jiaqi Chen

New Journal of Chemistry (1998-Present) 2017 vol. 41(Issue 24) pp:15260-15267

Publication Date(Web):2017/12/04

DOI:10.1039/C7NJ02632C

As a well-known inorganic thermochromic material, VO2(M) is attracting extensive attention regarding the synthetic methods and growth controls to improve its properties. A simple and convenient method is provided for the preparation of star-like VO2(M) nanomaterials with narrow hysteresis width around 4.3 °C. The sample is obtained by dehydration of a new intermedium, star-like VO2(M)·0.15H2O, whose possible formation mechanism has been proposed supported by time-dependent SEM growth images. Furthermore, the star-like VO2(M) shows excellent phase transition and optical switching properties that will be beneficial for highly sensitive electrical/optical devices or other applications.

Phase evolution and crystal growth of VO2 nanostructures under hydrothermal reactions

Co-reporter:Weilai Yu, Shuai Li and Chi Huang

RSC Advances 2016 vol. 6(Issue 9) pp:7113-7120

Publication Date(Web):12 Jan 2016

DOI:10.1039/C5RA23898F

The phase evolution and crystal growth of VO2 nanostructures against reaction time in a high-pressure V2O5–oxalic acid hydrothermal system were systematically investigated. It was found that the rather thin VO2 (B) nanobelts were first obtained, then stacked to form large belt-like structures and subsequently phase transformed into VO2 (A), based on an oriented attachment-recrystallization mechanism. The large VO2 (A) belt-like structures could further assemble into novel “snowflake” VO2 (M) microcrystals with even bigger sizes and nearly well-defined six-fold symmetry. Due to the Ostwald ripening effect regarding crystal size discrepancy, the VO2 (M) phase could further grow at the cost of the gradual dissolution of VO2 (A) and full elimination of VO2 (B). The phase evolution from VO2 (B) first to VO2 (A) and then to VO2 (M), is actually a step-by-step thermodynamically downhill process, owing to the gradual relaxation of structural tension within the VO2 crystal lattice. Thus, our investigation, for the first time, demonstrated the feasibility of the well-known Ostwald's step rules towards the phase evolution process of VO2 and could provide unprecedented new insight to promote understanding of the synthesis and properties of vanadium oxide compounds.

Synthesis and characterization of polypyrrole using TiO2 nanotube@poly(sodium styrene sulfonate) as dopant and template

Co-reporter:Xiongzhi Zhang;Yu Huang;Xiyan Huang;Houbin Li

Polymer Composites 2016 Volume 37( Issue 2) pp:462-467

Publication Date(Web):

DOI:10.1002/pc.23200

A polypyrrole (PPy) using TiO₂ nanotube@poly(sodium styrene sulfonate) (TiO₂@PSS) as dopant and template was synthesized by chemical oxidation polymerization. The template TiO₂@PSS consisting of a TiO₂ nanotube core and PSS on the surface was prepared by a “grafting from” approach. PPy on the layer of TiO₂@PSS (TiO₂@PSS/PPy) was characterized by transmission electron microscopy, scanning electron microscopy, X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectrometry (FTIR), Raman spectroscopic analysis, UV-visible (UV-vis) spectroscopy, thermo gravimetric analysis, and electrical conductivity analysis. Results showed that TiO₂@PSS/PPy was successfully fabricated. The electrical conductivity of the TiO₂@PSS/PPy nanocomposites at room temperature was 11.6 S cm⁻¹, which was higher than that of the PPy (4.2 S cm⁻¹). This result was consistent with those based on FTIR, UV-vis spectroscopy, and XPS analyses. The nanocomposites have nanoparticle size and controllable morphology and thus potential applications in photoelectrochemical devices, photocatalytic devices, conductive inks, electronic printing sensors, and electrodes. POLYM. COMPOS., 37:462–467, 2016. © 2014 Society of Plastics Engineers

Facile synthesis of V2O3 nanobelts by the transformation of VO2(B) with controllable phase transition property

Co-reporter:Zhan Zhan, Xinghai Liu, Houbin Li, Meijuan Fan, Chi Huang

Materials Letters 2016 Volume 165() pp:214-216

Publication Date(Web):15 February 2016

DOI:10.1016/j.matlet.2015.11.094

•The V2O3 nanobelts can be obtained by the precursor VO2(B) after calcination.•The Tc of annealed V2O3 is −107.25 °C, which is higher than −113 °C reported before.•The proportion of doped Cr could accurately change the Tc of the V2O3 in our study.V2O3 nanoparticles, with belt-like morphology, have been successfully synthesized by a facile hydrothermal route and subsequent calcination. It was found that the ratio of H2C2O4 plays a duel role in the formation of the precursor VO2(B) through the hydrothermal process and in the morphology of the annealed V2O3 nanoparticles. Furthermore, the phase transition properties of V2O3 nanobelts were studied by the differential scanning calorimetry (DSC) curve, which shows that the phase transition temperature (Tc) of the samples is higher and it could be changed accurately by the doping of Cr, indicating that the as-obtained V2O3 nanobelts had potential applications in electrochemical catalysts and conductive composite polymeric materials.

Facile fabrication of superhydrophobic coatings based on two silica sols

Co-reporter:Yanfen Huang;Shengping Yi;Zaosheng Lv

Colloid and Polymer Science 2016 Volume 294( Issue 9) pp:1503-1509

Publication Date(Web):2016 September

DOI:10.1007/s00396-016-3912-9

Superhydrophobic coatings were successfully fabricated by using two silica sols and fluorinated acrylate copolymers through the organic-inorganic hybrid method. The two silica sols contained different nanoparticles, namely, silica nanoparticles with many hydroxyl groups on their surfaces and silica nanoparticles with many long-chain alkyls on their surfaces. The integration of these two silica sols and fluorinated acrylate copolymers satisfied two necessary conditions of multi-scale nano/microstructures and low surface energy for fabricating superhydrophobic coatings. The superhydrophobic surfaces were constructed by using appropriate weight ratios of silica/copolymers and silica sol (methanol) contents. The superhydrophobic coatings displayed a water contact angle as high as 156.2° and contact angle hysteresis of 2.4°, which indicated their good self-cleaning capability. In particular, these coatings showed good mechanical properties and excellent thermal stabilities. The method is not only a facile and inexpensive way to achieve the lotus effect but could also create coatings with high values in practical application.

Preparation and performance of cationic flocculant for papermaking based on the graft polymerization of cationic chains from colloidal silica particles

Co-reporter:Xiongzhi Zhang, Yu Huang, Kaiqiao Fu, Shiju Yuan, Chi Huang, Houbin Li

Colloids and Surfaces A: Physicochemical and Engineering Aspects 2016 Volume 491() pp:29-36

Publication Date(Web):20 February 2016

DOI:10.1016/j.colsurfa.2015.12.003

•Cationic spherical polyelectrolyte brushes (CSPB) were synthesized by “grafting from” polymerization.•CSPB acted as flocculants or retention-aids for bleached eucalyptus kraft pulp and kaolin/pulp particles.•Bridging flocculation model may be the mainly mechanism for CSPB on flocculation of pulp.•The CSPB achieved a better flocculation and retention-aid efficiency than PDMC.The cationic spherical polyelectrolyte brushes (CSPB), with poly(2-(acryloyloxy) ethyltrimethylammonium chloride) chains grafted from the surfaces of colloidal silica particles were prepared and evaluated. The CSPB was characterized by Fourier-transform infrared spectrometry, thermo gravimetric analysis, colloid titration, gel permeation chromatography, transmission electron microscopy and X-ray photoelectron spectroscopy. The results show that CSPB with 1.8 × 10−3 mmol/g surface grafting density was successfully fabricated. The CSPB was investigated as flocculation and retention-aids for bleached eucalyptus kraft pulp and kaolin/pulp particles using relative turbidity, zeta potential, Focused beam reflectance measurement (FBRM), dynamic drainage jar and field emission scanning electron microscopy methods. The results showed that the zeta potential of pulp suspension gradually changed from negative to zero and then to positive, maximum flocculation occurred when the zeta potential was still negative. The data also suggested that the efficiency of both flocculation and retention-aid were increased and then demonstrated a gradual downward trend as the concentration of the CSPB increased. FBRM showed that flocs of CSPB had low re-flocculate ability. Bridging flocculation model may be the mainly mechanism for CSPB on flocculation of pulp.

High-performance interpenetrating polymer network polyurethane pervaporation membranes for butanol recovery

Co-reporter:Mingjie Hu;Le Gao;Wei Fu;Xinhai Liu;Fucai Huang;Yunbai Luo

Journal of Chemical Technology and Biotechnology 2015 Volume 90( Issue 12) pp:2195-2207

Publication Date(Web):

DOI:10.1002/jctb.4533

Abstract

BACKGROUND

Butanol produced by fermentation from waste biomass suffers from low final concentration. Separation of butanol from its dilute aqueous solution is of significant importance. Among various separation methods, pervaporation has been proved to be one of the most promising methods for the butanol–water system and developing pervaporation membranes with high performance is therefore of interest.

RESULTS

A high performance interpenetrating polymer network (IPN) polyurethane (PU) pervaporation membrane was obtained, giving membrane selectivity of 130.3 with butanol permeability of 2.5 × 10⁴ Barrer at 60 °C. Both membrane selectivity and butanol permeability increased with feed temperature at temperatures up to 60 °C and then decreased.

CONCLUSION

Hydroxyl-terminated polybutadiene (HTPB) based PU was used in pervaporation recovery of butanol. Pervaporation performance was obviously improved by formation of IPN structure. The pervaporation performance was studied using the solution-diffusion model and the mechanism of performance improvement was also studied. © 2014 Society of Chemical Industry

Synthesis of a cyclen-containing disubstituted polyacetylene with strong green photoluminescence and its application as a sensitive chemosensor towards sulfide anion with good selectivity and high sensitivity

Co-reporter:Yanfen Huang, Daxin Ou, Can Wang, Chi Huang, Qianqian Li and Zhen Li

Polymer Chemistry 2014 vol. 5(Issue 6) pp:2041-2049

Publication Date(Web):29 Oct 2013

DOI:10.1039/C3PY00873H

Through a postfunctional method, a new disubstituted polyacetylene (P2) bearing cyclen moieties in the side chains, was prepared conveniently and exhibited strong green fluorescence. P2 showed good pH stability in the solution mixture of THF/H2O (v/v = 1:1), and could report the presence of trace Cu2+ ions at a concentration as low as 1.0 × 10−7 mol L−1 in diluted solutions, through an on–off mode. By utilizing the displacement strategy, due to the much higher stability constant of the complex of S2− and Cu2+, the quenched fluorescence of P2 by Cu2+ ions could recover upon the addition of trace S2− anions, with a detection limit down to 2.0 × 10−7 mol L−1. Excitingly, no interference was observed from other anions, including AcO−, SO32−, HSO3−, HCO3−, CO32−, I−, Br−, Cl−, F−, S2O32−, C2O42−, P2O74−, SCN−, HSO4−, SO42−, NO2−, H2PO4−, HPO42−, PO43−, ClO4−, Cr2O72−, S2O82−, ClO3−, IO3−, CN− and NO3−, making P2 a new, sensitive and selective sulfide probe.

One-step hydrothermal conversion of VO2(B) into W-doped VO2(M) and its phase transition and optical switching properties

Co-reporter:Yifu Zhang, Xiongzhi Zhang, Yu Huang, Chi Huang, Fei Niu, Changgong Meng, Xiaoyu Tan

Solid State Communications 2014 180() pp: 24-27

Publication Date(Web):February 2014

DOI:10.1016/j.ssc.2013.10.028

One-pot synthesis of hyperbranched polyols and their effects as crosslinkers on HTPB-based polyurethane

Co-reporter:Hu Mingjie;Fu Wei;Gao Le;Wu Weibing;Liu Xinghai;Huang Chi

Polymer Bulletin 2014 Volume 71( Issue 10) pp:2671-2693

Publication Date(Web):2014 October

DOI:10.1007/s00289-014-1215-1

Hyperbranched polyethers and hyperbranched poly(amino ester)s were synthesized through one-pot method, and characterized by fourier transform infrared spectroscopy, hydrogen nuclear magnetic resonance and thermogravimetry analysis (TGA). The as-obtained hyperbranched polyols with different molecular structure and sizes were used to crosslink hydroxyl-terminated polybutadiene-based polyurethane (PU). The PU was characterized by tensile test, dynamic mechanical analysis, TGA, and swelling properties. It was found that the crosslinker structure and size have great effects on the properties of the PU. Hyperbranched polyether cross-linked PU showed the best mechanical properties, which reached mechanical strength of 1.45 MPa with elongation at break of 617 % for the third generation with hard segment content of 26.8 % at 25 °C.

Synthesis and characterization of addition-type silicone rubbers (ASR) using a novel cross linking agent PH prepared by vinyl-POSS and PMHS

Co-reporter:Yifu Zhang, Yongyun Mao, Dongzhi Chen, Weibing Wu, Shengping Yi, Shaobo Mo, Chi Huang

Polymer Degradation and Stability 2013 Volume 98(Issue 4) pp:916-925

Publication Date(Web):April 2013

DOI:10.1016/j.polymdegradstab.2013.01.009

A novel cross-linker (denoted as PH) prepared using vinyl-POSS and poly(methylhydrogensiloxane) (PMHS), was introduced to vinyl terminated polydimethylsiloxane (VPDMS) matrix to prepare a series of addition-type silicone rubbers (ASR) for the first time. Morphology, thermal properties and mechanical properties of these ASR were respectively studied by means of scanning electron microscope (SEM), thermal gravimetric analysis (TGA) and universal tensile testing machine. The results revealed that the thermal stabilities and mechanical properties of ASR were significantly enhanced by the addition of PH compared with the traditional cross-linker PMHS. It was found that the tensile strength of ASR prepared using PH as cross-linker was strikingly increased by 43.8% compared with the one prepared using PMHS as cross-linker. The striking enhancements in thermal properties and improvements on mechanical properties of ASR were likely attributed to the increase of dimensionality of novel cross-linked networks in novel ASR.

Facile hydrothermal synthesis of vanadium oxides nanobelts by ethanol reduction of peroxovanadium complexes

Co-reporter:Yifu Zhang, Chongxue Chen, Weibing Wu, Fei Niu, Xinghai Liu, Yalan Zhong, Yuliang Cao, Xin Liu, Chi Huang

Ceramics International 2013 Volume 39(Issue 1) pp:129-141

Publication Date(Web):January 2013

DOI:10.1016/j.ceramint.2012.06.001

Abstract

V₃O₇·H₂O and VO₂(B) nanobelts were successfully synthesized by a one-pot hydrothermal approach using peroxovanadium (V) complexes, ethanol and water as the starting materials. Some parameters, such as the ratio of ethanol/water, the reaction temperature and the reaction time, were briefly discussed to reveal the formation of vanadium oxides nanobelts. It was found that the ethanol was oxidized to aldehyde confirmed by the silver mirror reaction and gas chromatography. V₃O₇·H₂O and VO₂(B) nanobelts could be selectively synthesized by controlling the quantity of ethanol. The possible formation mechanism of the synthesis of vanadium oxides nanobelts was proposed. The electrochemical properties of V₃O₇·H₂O and VO₂(B) nanobelts were studied, and they exhibited a high initial discharge capacity of 350 mAh/g and 190 mAh/g, respectively. VO₂(M) nanobelts were prepared by the irreversible transformation of VO₂(B) nanobelts at 700 °C for 2 h under the inert atmosphere. The phase transition properties of VO₂(M) nanobelts were investigated by DSC and variable-temperature IR, which revealed that the as-obtained VO₂(M) nanobelts could be applied to the optical switching devices.

The additives W, Mo, Sn and Fe for promoting the formation of VO2(M) and its optical switching properties

Co-reporter:Yifu Zhang, Juecheng Zhang, Xiongzhi Zhang, Chi Huang, Yalan Zhong, Yuan Deng

Materials Letters 2013 Volume 92() pp:61-64

Publication Date(Web):1 February 2013

DOI:10.1016/j.matlet.2012.10.054

Belt-like X-doped VO2(M) (X=W, Mo, Sn or Fe) with rectangular cross sections were successfully synthesized by a facile one-pot hydrothermal approach. The as-obtained samples were characterized by XRD, XPS, SEM, DSC and variable-temperature IR. The results showed that the additives W, Mo, Sn and Fe could promote the formation of VO2(M) under hydrothermal conditions. The additives had little influence on the morphology of doped VO2(M), but they were the key factor for the synthesis of VO2(M). The W and Mo atoms could effectively reduce the Tc of VO2(M), while Sn and Fe atoms had little influence on Tc. Furthermore, it was found that the as-obtained doped VO2(M) possessed prominent thermochromic properties and optical switching characters.Graphical abstractThe additives W, Mo, Sn and Fe can promote the formation of VO2(M) under the hydrothermal conditions.Highlights► one-pot hydrothermal route was developed to fabricate belt-like doped VO2(M). ► Additives W, Mo, Sn and Fe can promote the formation of VO2(M). ► Additives have little influence on the morphology of doped VO2(M). ► W and Mo can reduce Tc of VO2(M), while Sn and Fe have little influence on Tc. ► Doped VO2(M) has thermochromic characters and optical switching properties.

Fabrication of V2O3/C core–shell structured composite and VC nanobelts by the thermal treatment of VO2/C composite

Co-reporter:Yifu Zhang, Meijuan Fan, Ling Hu, Weibing Wu, Juecheng Zhang, Xinghai Liu, Yalan Zhong, Chi Huang

Applied Surface Science 2012 Volume 258(Issue 24) pp:9650-9655

Publication Date(Web):1 October 2012

DOI:10.1016/j.apsusc.2012.06.004

Abstract

Belt-like V₂O₃ encapsulated into carbon tubes (V₂O₃/C) core–shell structured composite and vanadium carbide (VC) nanobelts have been successfully synthesized by the thermal treatment with VO₂/C core–shell structured composite through adjusting the heating temperature for the first time. The amorphous carbon on the surface of VO₂ plays a dual role in this thermal process, namely as the reductant to reduce VO₂ to V₂O₃ or VC, and as the carbon precursor for the V₂O₃/C carbon shell and VC. The as-obtained samples were respectively characterized by X-ray powder diffraction, energy-dispersive X-ray spectrometer, Raman spectrum, elemental analysis, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy and Brunauer–Emmett–Teller. V₂O₃/C was successfully synthesized at 700–900 °C for 2 h, and VC nanobelts were successfully prepared at 1000 °C for 2 h. The as-obtained V₂O₃/C composite and VC nanobelts contain C–H groups, which will facilitate the linkage of catalytic species or polymers to the surface in their potential applications. V₂O₃/C composite has higher specific surface area than that of VC due to the amorphous carbon coated on the surface of V₂O₃. Furthermore, the thermal stability of VC in air was investigated by Thermo-Gravimetric/Differential Thermal Analyzer, revealing that it had good thermal stability and oxidation resistance below 335 °C in air.

Preparation of W- and Mo-doped VO2(M) by ethanol reduction of peroxovanadium complexes and their phase transition and optical switching properties

Co-reporter:Yifu Zhang, Wei Li, Meijuan Fan, Fangfang Zhang, Juecheng Zhang, Xinghai Liu, Haining Zhang, Chi Huang, Houbin Li

Journal of Alloys and Compounds 2012 Volume 544() pp:30-36

Publication Date(Web):15 December 2012

DOI:10.1016/j.jallcom.2012.07.093

Thermochromic W- and Mo-doped VO2(M) with a various doped contents were successfully synthesized using peroxovanadium (V) complexes as the vanadium precursor and green solvent (ethanol) as the reducing agent by a facile hydrothermal approach and subsequent calcination for the first time. The samples were characterized by X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), inductive coupled plasma emission spectrometer (ICP), differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FT-IR). The results revealed that W or Mo atoms were successfully doped into the crystal lattice of VO2 matrix, and the as-prepared W- and Mo-doped VO2(M) had a belt-like morphology. The phase transition temperature of doped VO2(M) could be simply tuned by changing the doping concentration of W or Mo atoms. The variable-temperature infrared spectra disclosed that the doped VO2(M) had outstanding thermochromic characters and optical switching properties.Highlights► W- and Mo-doped VO2(M) with a various doped contents were synthesized. ► The doped VO2(M) has a belt-like morphology. ► The Tc of doped VO2(M) can be simply tuned by changing the doping concentration. ► The doped VO2(M) has thermochromic characters and optical switching properties.

Direct fabrication of organic carbon coated VO2(B) (VO2(B)@C) core–shell structured nanobelts by one step hydrothermal route and its formation mechanism

Co-reporter:Yifu Zhang, Juecheng Zhang, Yalan Zhong, Lei Yu, Yuan Deng, Chi Huang, Xinghai Liu

Applied Surface Science 2012 Volume 263() pp:124-131

Publication Date(Web):15 December 2012

DOI:10.1016/j.apsusc.2012.09.012

Abstract

Organic carbon coated vanadium dioxide (VO₂(B)@C) core–shell structured nanobelts were successfully synthesized using V₂O₅ and glucose solution as the starting materials by a facile one-step hydrothermal route. The as-obtained core–shell materials were characterized by scanning electron microscope, transmission electron microscopy, X-ray powder diffraction, energy-dispersive X-ray spectrometer, elemental analysis, Fourier transform infrared spectroscopy and Raman measurements. Some parameters, such as, the concentration of glucose and the reaction time, were briefly discussed to disclose the formation process of VO₂(B)@C core–shell structured nanobelts. Glucose played a dual role in the hydrothermal process, namely as a reductant to reduce V₂O₅ to VO₂(B), and as a carbon precursor for the organic carbon shell. The proper quantity of glucose (i.g.: 0.27 g) was beneficial for the fabrication of VO₂(B)@C. Furthermore, the possible formation mechanism of VO₂(B)@C core–shell structured nanobelts was proposed.

Synergistic effect between POSS and fumed silica on thermal stabilities and mechanical properties of room temperature vulcanized (RTV) silicone rubbers

Co-reporter:Dongzhi Chen, Yan Liu, Chi Huang

Polymer Degradation and Stability 2012 Volume 97(Issue 3) pp:308-315

Publication Date(Web):March 2012

DOI:10.1016/j.polymdegradstab.2011.12.016

In this paper, both divinyl-hexa[(trimethoxysilyl)ethyl]-POSS (DVPS) and fumed silica were firstly introduced into polydimethylsiloxane (PDMS) system using as the cross-linker and the reinforcing filler respectively. And a series of novel RTV silicone rubbers synergistically enhanced by DVPS and fumed silica were prepared. The cross-linked networks in the novel RTV silicone rubbers have been studied by attenuated total reflection infrared spectroscopy, and the dispersions of POSS and fumed silica in these novel RTV silicone rubbers have been observed by means of scanning electron microscope (SEM). And thermal stabilities, thermo-oxidative stabilities and mechanical properties of these novel RTV silicone rubbers were studied by means of thermal gravimetric analysis and universal tensile testing machine, respectively. From the obtained results, it was found that synergistic effect between POSS-rich areas and fumed silica on thermal stability and mechanical property of RTV silicone rubber indeed existed. And the experimental results also exhibited that the thermal stabilities and mechanical properties of the novel RTV silicone rubbers were far better than those of the reference materials (DVPR and MTFR). The striking enhancements in thermal properties and improvements on mechanical properties of novel RTV silicone rubbers were likely attributed to the synergistic effect between POSS-rich domains and fumed silica. Meanwhile, it was found that the mechanical properties of RTV silicone rubbers prepared with a given amount of POSS cross-linker were enhanced with the increment of the loading amount of fumed silica.

Beltlike V2O3@C CoreShell-Structured Composite: Design, Preparation, Characterization, Phase Transition, and Improvement of Electrochemical Properties of V2O3

Co-reporter:Yifu Zhang;Meijuan Fan;Xinghai Liu;Houbin Li

European Journal of Inorganic Chemistry 2012 Volume 2012( Issue 10) pp:1650-1659

Publication Date(Web):

DOI:10.1002/ejic.201101266

Abstract

A beltlike V₂O₃@C core–shell-structured composite was successfully synthesized by thermal treatment with the precursor V₃O₇·H₂O@C composite under an inert atmosphere. The phase, composition, structure, and morphology of the as-obtained samples were confirmed by XRD, elemental analysis, FTIR, energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), IR Raman, SEM, and TEM measurements. The process of the formation of V₂O₃@C is briefly discussed. The carbon coated onto the surface of V₂O₃ is disordered, and V₂O₃ keeps the original morphology of V₃O₇·H₂O. V₂O₃@C has an average length that ranges from 0.4 to 5.2 μm, a width of about 80–170 nm, and an average thickness of the shells of about 15.6 nm. The possible formation mechanism of V₂O₃@C is proposed as follows: the reaction undergoes a solid-state reaction by the interface reaction between V₃O₇ cores and carbon shells. It was found that the V₂O₃@C composite possesses the same phase-transition properties as V₂O₃, which could expand the possible applications of materials related to V₂O₃ in the future. Furthermore, a V₂O₃ sphere, a V₂O₃ nanobelt, and the beltlike V₂O₃@C composite were explored as cathode materials for application in lithium-ion batteries. The beltlike V₂O₃@C composite electrode exhibited the best electrochemical properties among them, thereby achieving our aim of improving the electrochemical properties of V₂O₃.

A novel route to fabricate belt-like VO2(M)@C core-shell structured composite and its phase transition properties

Co-reporter:Yifu Zhang, Meijuan Fan, Weibing Wu, Ling Hu, Juecheng Zhang, Yongyun Mao, Chi Huang, Xinghai Liu

Materials Letters 2012 Volume 71() pp:127-130

Publication Date(Web):15 March 2012

DOI:10.1016/j.matlet.2011.12.061

Belt-like VO2(M)@C core-shell structured composite was successfully fabricated by the thermal treatment with V3O7·H2O@C composite under a flow of Ar gas at 500 °C for 12 h. The processes of the formation of VO2(M)@C were briefly discussed. The core exhibited monoclinic phase VO2(M) and the carbon coated on the surface of VO2(M) was amorphous. The as-obtained VO2(M)@C composite consisted of belt-like shape with width ranging from 50 to 250 nm, length ranging from a few hundred nanometers to several micrometers and the thickness of carbon was about 18.5 nm on average. Furthermore, the phase transition property of VO2(M)@C was measured by DSC, revealing that VO2(M)@C also had the reversible first-order metal-to-insulator transition in the case of VO2(M).Highlights► A novel route was developed to fabricate VO2(M)@C. ► Belt-like VO2(M)@C core-shell structured composite was synthesized for the first time. ► The process of the formation of VO2(M)@C is briefly discussed. ► VO2(M)@C core-shell composite owns the phase transition property of VO2(M).

Synthesis of V O2(A) nanobelts by the transformation of V O2(B) under the hydrothermal treatment and its optical switching properties

Co-reporter:Yifu Zhang, Meijuan Fan, Xinghai Liu, Guangyong Xie, Houbin Li, Chi Huang

Solid State Communications 2012 Volume 152(Issue 4) pp:253-256

Publication Date(Web):February 2012

DOI:10.1016/j.ssc.2011.11.036

V O2(A) nanobelts had been successfully synthesized by the transformation of V O2(B) using H2O as the solvent under the hydrothermal approach at 280 °C for 48 h. Some parameters, such as the reaction temperature and time, had been briefly discussed to reveal the transition from V O2(B) to V O2(A). It was found that H2O played a crucial role in the transition from V O2(B) to V O2(A). The phase transition of V O2(A) nanobelts was at 162 °C. The optical switching properties of V O2(A) were studied by the variable-temperature infrared spectra for the first time. In addition, V O2(A) nanobelts were calcined at 700 °C for 2 h under a high purity Ar (99.999%) atmosphere to obtain V O2(M) which exhibited a strong crystallographic transition at around 65 °C.Highlights► V O2(A) nanobelts have been synthesized by the transformation of V O2(B). ► The phase transition of V O2(A) nanobelts is at 162 °C. ► V O2(A) can be used as the optical switch. ► V O2(A) can be converted to V O2(M).

Preparation and characterization of silica/fluorinated acrylate copolymers hybrid films and the investigation of their icephobicity

Co-reporter:Yanfen Huang, Mingjie Hu, Shengping Yi, Xinghai Liu, Houbin Li, Chi Huang, Yunbai Luo, Yan Li

Thin Solid Films 2012 Volume 520(Issue 17) pp:5644-5651

Publication Date(Web):30 June 2012

DOI:10.1016/j.tsf.2012.04.067

Inexpensive hydrophobic and icephobic coatings and films were obtained by a simple method. These coatings were prepared by mixing silica sol and fluorinated acrylate copolymers. There was a phase separation process in the film-forming which can provide the excellent performance. Small amount (about 2 wt.%) of fluorinated (methyl) acrylate was used in all of these coatings. The coatings were eco-friendly by using ethanol as the solvent system. Scanning electron microscopy, atomic force microscope, energy dispersive X-ray fluorescence spectrometer, water contact angle, thermal gravimetric analysis and tests of adhesion and hardness had been performed to characterize the morphological feature, chemical composition, hydrophobicity and icephobicity of the surface, thermal stability and mechanical properties of the coatings. The results showed that the films had good hydrophobicity, high thermal stability and excellent mechanical properties of adhesion strength and pencil hardness. Furthermore, by testing their properties of delaying water droplet from icing, it was found that ice formation was delayed for 90 min compared with the glass surface at − 5.6 °C. The hybrid coatings may be suitable for large-scale and practical application owing to its flexibility and simplicity.Highlights► Coatings were prepared by mixing fluorinated acrylate copolymer and silica. ► Mechanical properties and anti-icing performance of the coatings were examined. ► Water contact angle increased with raising SiO2 (sol)/monomers weight ratio. ► Ice formation was delayed for 90 min at − 5.6 °C.

Synthesis and characterization of belt-like VO2(B)@carbon and V2O3@carbon core–shell structured composites

Co-reporter:Yifu Zhang, Fangfang Zhang, Lei Yu, Meijuan Fan, Yalan Zhong, Xinghai Liu, Yongyun Mao, Chi Huang

Colloids and Surfaces A: Physicochemical and Engineering Aspects 2012 Volume 396() pp:144-152

Publication Date(Web):20 February 2012

DOI:10.1016/j.colsurfa.2011.12.058

VO2(B) nanobelts encapsulated into carbon core–shell structured composite (VO2(B)@C) was successfully synthesized using VO2(B) nanobelts as the cores and glucose as the shells via an environmental hydrothermal method. The “adsorption carbonization growth” (ACG) mechanism was proposed to explain the formation of VO2(B)@C. The influence of synthetic parameters, such as, the reaction temperature, concentration of glucose and reaction time, was systematically investigated to control the fabrication of VO2(B)@C. Subsequently, belt-like V2O3@C core–shell structured composite was prepared by the heating treatment of VO2(B)@C. Furthermore, the electrochemical properties of this novel belt-like V2O3@C core–shell structured composite was studied, indicating that it exhibits an initial discharge capacity of as high as 162 mAh/g and the discharge capacity is still 104, 89, 67 mAh/g after 30, 50, and 89 cycles, which is much higher than pure V2O3. The phase transition properties of V2O3 powder and V2O3@C composite were investigated by DSC, which revealed that V2O3@C has the same phase transition properties of V2O3. The as-obtained V2O3@C composite has potential applications to the cathode and functional positive temperature coefficient (PTC) materials.Graphical abstractHighlights► VO2(B)@C core–shell structured composite has been successfully synthesized. ► The ACG mechanism was proposed to explain the formation of VO2(B)@C. ► Belt-like V2O3@C composite was first prepared using VO2(B)@C as the precursor. ► The electrochemical property of V2O3 has been greatly improved by V2O3@C. ► V2O3@C core–shell composite owns the phase transition property of V2O3.

Facile synthesis, phase transition, optical switching and oxidation resistance properties of belt-like VO2(A) and VO2(M) with a rectangular cross section

Co-reporter:Yifu Zhang, Yanfen Huang, Juecheng Zhang, Weibing Wu, Fei Niu, Yalan Zhong, Xinghai Liu, Xin Liu, Chi Huang

Materials Research Bulletin 2012 47(8) pp: 1978-1986

Publication Date(Web):

DOI:10.1016/j.materresbull.2012.04.015

Fabrication of V3O7·H2O@C core-shell nanostructured composites and the effect of V3O7·H2O and V3O7·H2O@C on decomposition of ammonium perchlorate

Co-reporter:Yifu Zhang, Xinghai Liu, Dongzhi Chen, Lei Yu, Jiaorong Nie, Shengping Yi, Houbin Li, Chi Huang

Journal of Alloys and Compounds 2011 Volume 509(Issue 5) pp:L69-L73

Publication Date(Web):3 February 2011

DOI:10.1016/j.jallcom.2010.10.154

V3O7·H2O@C core-shell materials have been synthesized using V3O7·H2O nanobelts as the cores and glucose as the source of carbon via an environmental hydrothermal method. The as-obtained V3O7·H2O@C core-shell materials were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), elemental analysis (EA), Fourier transform infrared spectroscopy (FT-IR) and Raman spectrum. The influences of the reaction temperature, concentration of glucose and reaction time on the morphologies of the samples were respectively discussed in detail. The possible formation mechanism of V3O7·H2O@C was proposed according to our experimental results. Furthermore, the effect of V3O7·H2O and V3O7·H2O@C on the thermal decomposition of ammonium perchlorate (AP) were investigated by thermal gravimetric analyzer (TG) and differential thermal analysis (DTA). The thermal decomposition temperatures of AP in the presence of V3O7·H2O and V3O7·H2O@C were reduced by 70 and 89 °C, respectively, which indicates that V3O7·H2O@C core-shell composites have higher activity than V3O7·H2O.

Improve the catalytic activity of α-Fe2O3 particles in decomposition of ammonium perchlorate by coating amorphous carbon on their surface

Co-reporter:Yifu Zhang, Xinghai Liu, Jiaorong Nie, Lei Yu, Yalan Zhong, Chi Huang

Journal of Solid State Chemistry 2011 Volume 184(Issue 2) pp:387-390

Publication Date(Web):February 2011

DOI:10.1016/j.jssc.2010.12.004

Sphere- and pod-like α-Fe2O3 particles have been selectively synthesized using NH3·H2O and NaOH solution to adjust the pH value of the designed synthetic system, respectively. The sphere-like α-Fe2O3 particles with diameter about 25 nm on average were encapsulated into carbon shells to fabricate a novel core–shell composite (α-Fe2O3@C) through the coating experiments. The catalytic performance of the products on the thermal decomposition of ammonium perchlorate (AP) was investigated by thermal gravimetric analyzer (TG) and differential thermal analysis (DTA). The thermal decomposition temperatures of AP in the presence of pod-like α-Fe2O3, sphere-like α-Fe2O3 and α-Fe2O3@C are reduced by 72, 81 and 109 °C, respectively, which show that α-Fe2O3@C core–shell composites have higher catalytic activity than that of α-Fe2O3.Graphical abstractThe catalytic performance of pod-like α-Fe2O3, sphere-like α-Fe2O3 and α-Fe2O3@C on the thermal decomposition of ammonium perchlorate (AP).Research highlights► Sphere- and pod-like α-Fe2O3 particles have been selectively synthesized using NH3·H2O and NaOH solution to adjust the pH value. ► A novel core–shell composite (α-Fe2O3@C core–shell structured composite) has been successfully synthesized using sphere-like α-Fe2O3 particles as the cores and glucose as the source of carbon. ► The thermal decomposition temperatures of AP in the presence of pod-like α-Fe2O3, sphere-like α-Fe2O3 and α-Fe2O3@C are reduced by 72, 81 and 109 °C, respectively, which shows that these materials have high catalytic activity.

Synthesis and characterization of novel room temperature vulcanized (RTV) silicone rubbers using octa[(trimethoxysilyl)ethyl]-POSS as cross-linker

Co-reporter:Dongzhi Chen, Shengping Yi, Pengfei Fang, Yalan Zhong, Chi Huang, Xiaojun Wu

Reactive and Functional Polymers 2011 71(4) pp: 502-511

Publication Date(Web):April 2011

DOI:10.1016/j.reactfunctpolym.2010.12.010

Preparation of V2O3 nanopowders by supercritical fluid reduction

Co-reporter:Xinghai Liu, Yifu Zhang, Shengping Yi, Chi Huang, Jun Liao, Houbin Li, Di Xiao, Hongyun Tao

The Journal of Supercritical Fluids 2011 Volume 56(Issue 2) pp:194-200

Publication Date(Web):March 2011

DOI:10.1016/j.supflu.2010.11.012

V2O3 nanoparticles, with diameters of 30–60 nm, have been synthesized by supercritical ethanol fluid reduction of VOC2O4. It was found that the reaction time has little influence on the purity and morphology of as-prepared products. And carbon oxides decomposed from C2O42− were conducive to the formation of the uniform sphere-like nanoparticles. The reaction mechanism of synthesizing uniform V2O3 nanoparticles is believed to be the redox reaction between VOC2O4 and ethanol in the supercritical condition. The crystal growth mechanism was proposed on the basis of the discussion about the formation process of the uniform sphere-like nanoparticles.Graphical abstractResearch highlights▶ A novel method for preparing V2O3 nanoparticles with spherical morphology was disclosed by supercritical ethanol fluid reduction of VOC2O4. ▶ The carbon oxides decomposed from C2O42− were conducive to the formation of the uniform sphere-like nanoparticles. ▶ The mechanism for preparation of V2O3 nanoparticles is the redox reaction of VOC2O4 with ethanol in the supercritical condition and the crystal growth was also proposed.

Thermal behaviour and mechanical properties of novel RTV silicone rubbers using divinyl-hexa[(trimethoxysilyl)ethyl]-POSS as cross-linker

Co-reporter:Dongzhi Chen, Jiaorong Nie, Shengping Yi, Weibing Wu, Yalan Zhong, Jun Liao, Chi Huang

Polymer Degradation and Stability 2010 Volume 95(Issue 4) pp:618-626

Publication Date(Web):April 2010

DOI:10.1016/j.polymdegradstab.2009.12.002

Divinyl-hexa[(trimethoxysilyl)ethyl]-POSS (DVPS) as an octavinyl-POSS derivative was first prepared. A series of novel polydimethylsiloxane (PDMS)/DVPS hybrid materials as room temperature vulcanized (RTV) silicone rubber were prepared. The chemical incorporation of novel POSS into hydroxyl-terminated PDMS system by hydrolytic condensation reaction was verified by attenuated total reflection (ATR) infrared spectroscopy. Thermal degradation, thermo-oxidative stability and mechanical properties of these novel RTV silicone rubbers were studied by means of thermogravimetric analysis and tensile testing. The results exhibited significantly enhanced effects on the thermal stabilities and mechanical properties as compared to the PDMS polymer prepared with tetraethoxysilane (TEOS). The observed improvements in thermal properties could be attributed to the effective three-dimensional network structures resulting from the structure of DVPS. The thermal decomposition of the RTV silicone rubbers in nitrogen was also monitored by TGA coupled with real-time FTIR, and the degradation residues were also characterized by FTIR. It was found that the POSS cross-linker facilitated the formation of cross-links in the degradation residues. The striking improvement in mechanical properties could be attributed to the synergistic action of the structure of three-dimensional multi-arm cross-linker (vinyl-POSS derivative), the plasticization of self-cross-linking Vinyl-POSS derivative and perfect distribution of vinyl-POSS derivative.

Synthesis and characterization of novel room temperature vulcanized (RTV) silicone rubbers using Vinyl-POSS derivatives as cross linking agents

Co-reporter:Dongzhi Chen, Shengping Yi, Weibing Wu, Yalan Zhong, Jun Liao, Chi Huang, Wenjuan Shi

Polymer 2010 Volume 51(Issue 17) pp:3867-3878

Publication Date(Web):4 August 2010

DOI:10.1016/j.polymer.2010.06.028

Two kinds of novel POSS cross-linkers were firstly prepared via hydrosilylation of Vinyl-POSS and trimethoxysilane. And two types of novel polydimethylsiloxane (PDMS) polymer composites as RTV silicone rubbers were prepared using Vinyl-POSS derivatives as cross-linkers in the presence of organotin catalyst. To completely exhibit superiorities of two kinds of novel cross-linkers, RTV silicone rubbers prepared with two proportions of different cross-linkers were assessed. The chemical inclusion of novel POSS into PDMS networks by hydrolytic condensation reaction was verified by attenuated total reflection (ATR) infrared spectroscopy. Morphologies, thermal properties, mechanical properties and hardness of these novel RTV silicone rubbers were studied. The results exhibited significantly enhanced effects of POSS on thermal stabilities, mechanical properties and hardness as compared to the PDMS polymers prepared with the traditional tetra-functional TMOS and TEOS cross-linkers. The striking improvements in thermal properties, mechanical properties and hardness could be attributed to the synergistic effect of the increase of dimensionality of cross-linked networks in novel RTV silicone rubbers resulting from special three-dimensional structure of novel POSS cross-linkers, plasticization of self-cross-linked POSS cross-linkers and uniform distribution of POSS cross-linkers.

Hydrothermal synthesis, characterization, formation mechanism and electrochemical property of V3O7·H2O single-crystal nanobelts

Co-reporter:Yifu Zhang, Xinghai Liu, Guangyong Xie, Lei Yu, Shengping Yi, Mingjie Hu, Chi Huang

Materials Science and Engineering: B 2010 Volume 175(Issue 2) pp:164-171

Publication Date(Web):25 November 2010

DOI:10.1016/j.mseb.2010.07.023

Single-crystal V3O7·H2O nanobelts have been successfully synthesized in a large-scale by ethanol reducing of the commercial V2O5 powder via a facile hydrothermal approach, without any templates and surfactants. The as-prepared V3O7·H2O nanobelts are up to several tens of micrometers in length, about 100 nm in width and about 20 nm in thickness in average, respectively. The “Hydrating–Reducing–Exfoliating–Splitting” (HRES) mechanism was proposed to describe the formation of the V3O7·H2O nanobelts. In our research progress, it was found that the ratio of EtOH/H2O, the reaction time and categories of the reducing agents had significant effects on the morphology and composition of as-obtained products. Furthermore, the electrochemical properties of V3O7·H2O nanobelts were preformed and the results revealed that a lithium battery using those nanobelts as the positive electrode exhibited a high initial discharge capacity of 373 mAh/g.

A facile method for preparing VO2 nanobelts

Co-reporter:Xinghai Liu, Guangyong Xie, Chi Huang, Qian Xu, Yifu Zhang, Yunbai Luo

Materials Letters 2008 Volume 62(12–13) pp:1878-1880

Publication Date(Web):30 April 2008

DOI:10.1016/j.matlet.2007.10.022

Metastable VO2 nanobelts were synthesized via a facile hydrothermal approach. Then the as-obtained samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectra (XPS), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Typical samples exhibited monoclinic phase VO2 (B) indexed as XRD, and the XPS results demonstrated that the V (IV) existed only in vanadium oxides. According to the results of TEM and SEM, the VO2 (B) nanobelts were 0.6–2.2 μm long, typically 70–180 nm wide and 20–30 nm thick. Some factors that affected the shape of One-dimensional (1-D) VO2 nanomaterials were briefly discussed.

Synthesis of V O2(A) nanobelts by the transformation of V O2(B) under the hydrothermal treatment and its optical switching properties

Co-reporter:Yifu Zhang, Meijuan Fan, Xinghai Liu, Guangyong Xie, Houbin Li, Chi Huang

Solid State Communications (February 2012) Volume 152(Issue 4) pp:253-256

Publication Date(Web):1 February 2012

DOI:10.1016/j.ssc.2011.11.036