Co-reporter:Wei Wang;Ying Liu;Yi Zhong;Linping Zhang;Hong Xu
Industrial & Engineering Chemistry Research October 30, 2013 Volume 52(Issue 43) pp:15066-15074
Publication Date(Web):2017-2-22
DOI:10.1021/ie401827s
Ordered mesoporous carbon–aluminum-doped zinc oxide (C-AZO) composites were prepared by the solvent-evaporation induced self-assembly method (EISA). The mesoporous structure was evaluated by small-angle X-ray scattering (SAXS), transmission electron microscopy (TEM), and N2 adsorption–desorption. The results showed that the composites had uniform pore size and high surface area. Textural characteristics of the nanocomposites were affected by the carbonization temperature. The specific area and pore volume increased upon increasing the calcination temperature, while the pore diameter decreased. The infrared emissivity value (8–14 μm) of ordered mesoporous C-AZO was measured by an IR-2 Infrared Emissometer. The results showed that infrared emissivity was as low as 0.39, which exhibited outstanding performance of infrared stealth.
Co-reporter:Hong Yu;Yuanfeng Wang;Hong Xu;Yi Zhong;Linping Zhang
Industrial & Engineering Chemistry Research May 28, 2014 Volume 53(Issue 21) pp:8927-8934
Publication Date(Web):2017-2-22
DOI:10.1021/ie501071h
Low add-on technologies have attracted more and more attention due to the shortage of water resources. In order to explore the mechanism of low add-on technologies, the states of water and the pore properties (pore size distribution, total pore volume, specific surface area, and the average of pore radius) of cotton fibers were investigated over a wide moisture range by using differential scanning calorimetry (DSC) based on the Gibbs–Thomson effect. A simple model of cotton fiber with various moisture ratios was given. Larger pores changed in size with the change of moisture ratio prior to smaller pores in both wetting and drying of cotton fibers. The information obtained could be used to explain the results of dyeing processes. Low add-on technology (wet pick-up 30–40%) was a favorable choice for surface treatment. Excellent surface performance of fabric could be obtained, and large amounts of water and energy could be saved by low add-on technology.
Co-reporter:Yingzhan Li, Lei Xu, Bo Xu, Zhiping Mao, Hong Xu, Yi Zhong, Linping Zhang, Bijia Wang, and Xiaofeng Sui
ACS Applied Materials & Interfaces May 24, 2017 Volume 9(Issue 20) pp:17155-17155
Publication Date(Web):May 4, 2017
DOI:10.1021/acsami.7b03600
Robust and flexible cellulose sponges were prepared by dual-cross-linking cellulose nanofiber (CNF) with γ-glycidoxypropyltrimethoxysilane (GPTMS) and polydopamine (PDA) and used as carriers of metal nanoparticles (NPs), such as palladium (Pd). In situ growth of Pd NPs on the surface of CNF was achieved in the presence of polydopamine (PDA). The modified sponges were characterized with FT-IR, XRD, EDX, SEM, TEM, and TGA. XRD, EDX, and TEM results revealed that the Pd NPs were homogeneously dispersed on the surface of CNF with a narrow size distribution. The catalysts could be successfully applied to heterogeneous Suzuki and Heck cross-coupling reactions. Leaching of Pd was negligible and the catalysts could be conveniently separated from the products and reused.Keywords: catalysts; Cellulose nanofiber; palladium; polydopamine; sponge;
Co-reporter:Zhiping Mao;Xiandong Zeng;Xiaofeng Sui;Feng Pan;Linping Zhang;Jiawei Li;Yi Zhong;Hong Xu
Industrial & Engineering Chemistry Research April 22, 2015 Volume 54(Issue 15) pp:3788-3799
Publication Date(Web):Publication Date (Web): March 26, 2015
DOI:10.1021/ie504510t
A novel phenylethynyl-terminated cyclotriphosphazene oligoimides (hexakis (4-phenyl acetylene imide phenoxy) cyclotriphosphazene, HPAIPC) was synthesized to solve the conflict between flame retardance and antidripping of poly(ethylene terephthalate) (PET). The PET/HPAIPC composites were prepared by direct melt compounding, and the flame-retardancy and antidripping properties of the composites were investigated. The results revealed that thermal stability, self-extinguishing ability, and inhibition of melt-dripping properties of PET/HPAIPC composites were obviously enhanced by the introduction of high-temperature auto-cross-linking cyclotriphosphazene oligomides into polyester. All results of rheological analyses, pyrolysis products, and the morphology of the char demonstrated that the HPAIPC could exhibit a greater complex viscosity and enhance the physical barrier effect retarding the flammable gases, heat flux, and flame.
Co-reporter:Zhiping Mao, Ruyi Xie, Dawei Fu, Linping Zhang, Hong Xu, Yi Zhong, Xiaofeng Sui
Separation and Purification Technology 2017 Volume 176() pp:277-286
Publication Date(Web):4 April 2017
DOI:10.1016/j.seppur.2016.12.027
•The composite fiber mats were obtained by coaxial electrospinning technology.•The photocatalytic and antibacterial property of fiber mats were evaluated.•The fiber mats exhibited improved photocatalytic activity and good recyclability.•They showed efficient antibacterial property against both kinds of bacteria.The visible light-responsive photocatalyst Ag-AgBr@Bi20TiO32 exhibited both high photocatalytic activity and antibacterial activity. To achieve the efficient immobilization of Ag-AgBr@Bi20TiO32, coaxial electrospinning technology was adopted to fabricate the novel multifunctional PAN/Ag-AgBr@Bi20TiO32 electrospun fiber mats. The characterization results indicated that the surface of each electrospun fiber was uniformly covered with the Ag-AgBr@Bi20TiO32 photocatalyst. The loaded Ag-AgBr@Bi20TiO32 endowed the composite fiber mats with an excellent photocatalytic activity and recyclability for the degradation of the herbicide isoproturon under visible light irradiation. Meanwhile, it showed efficient antibacterial activity against both the Gram-positive bacteria S. aureus and Gram-negative bacteria E. coli due to the synergistic effect between the silver, which has innate antibacterial activity, and active species, which have a strong oxidation ability, generated on the surface of the photocatalyst. Given the above research results, the flexible PAN/Ag-AgBr@Bi20TiO32 electrospun fiber mats would have potential applications in the water/air purification field and biochemical protective clothing.
Co-reporter:Jiaying Yang, Hong Xu, Linping Zhang, Yi Zhong, Xiaofeng Sui, Zhiping Mao
Surface and Coatings Technology 2017 Volume 309() pp:149-154
Publication Date(Web):15 January 2017
DOI:10.1016/j.surfcoat.2016.11.058
•The uniform deposition of copper nanoparticles are formed by the in-situ reduction of dopamine.•The fabric has superhydrophobicity after 30 washing cycles and after dyeing.•The fabric has high antibacterial activity against E. coli after 50 washing cycles and after dyeing.A simple two-step impregnation method was used to prepare copper nanoparticles coated cotton fabric. In which, dopamine firstly self-polymerized to polydopamine membrane on the cotton fabric surface, then copper nanoparticles were obtained and bound onto the cotton fabric using polydopamine as a reductant and binder. Field emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS) and Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES) were used to observe the surface morphology and analyze the elemental composition as well as their surface chemical states of all samples. The results confirmed the formation of polydopamine film and copper nanoparticles. The results of contact angle measurements and antibacterial tests showed that the modified cotton fabrics had durable sticky superhydrophobicity and considerable antibacterial activity.
Co-reporter:Yingying Jiang;Linping Zhang;Hong Xu
Journal of Sol-Gel Science and Technology 2017 Volume 82( Issue 2) pp:370-379
Publication Date(Web):2017 May
DOI:10.1007/s10971-017-4323-1
In this work, aluminum hydroxide aerogel was successfully assembled on polysulfonamide fabrics by sol–gel forming method to improve the thermal insulation and flame resistance properties. The presence of aluminum hydroxide aerogels assembled on the surface of polysulfonamide fabrics was verified by the scanning electron microscopy. The aerogel was crystalized in γ-AlOOH boehmite form characterized by X-ray powder diffraction. The heat insulation and flame resistance of polysulfonamide fabrics were improved by coating aluminum hydroxide aerogels. When the molar ratio of propylene oxide to aluminum chloride hexahydrate was 4:1, the prepared aluminum hydroxide aerogel marked as SAl-2 had the largest pore volume with the value of 2.33 cm3/g, the corresponding apparent density was 0.172 g/cm3, the specific surface area was 392 m2/g, the average pore diameter was 18.6 nm, and it gave the best thermal insulation property. Compared with the original polysulfonamide fabric, the thermal conductivity of the composite fabric was decreased from 0.0513 to 0.0301 W/(m·K). When the molar ratio of propylene oxide to aluminum chloride hexahydrate was 3:1, the prepared aluminum hydroxide aerogel marked as SAl-1 had the smallest pore volume with the value of 0.72 cm3/g, the corresponding apparent density was 0.645 g/cm3, the specific surface area was 293 m2/g, the average pore diameter was 10.9 nm, and it gave the best flame resistance property. Compared with the original polysulfonamide fabric, the vertical burning damage length was shorted from 4.90 to 1.30 cm.Open image in new window
Co-reporter:Ruyi Xie, Linping Zhang, Hongchen Liu, Hong Xu, Yi Zhong, Xiaofeng Sui, Zhiping Mao
Materials Research Bulletin 2017 Volume 94(Volume 94) pp:
Publication Date(Web):1 October 2017
DOI:10.1016/j.materresbull.2017.05.040
•The flexible fiber membranes were prepared by coaxial electrospinning technique.•CQDs-Bi20TiO32 photocatalyst was uniformly fixed on the surfaces of PAN fibers.•The fiber membranes had high photocatalytic activity for degradation of isoproturon.•The composite fiber membranes exhibited good recyclability.The CQDs-Bi20TiO32 photocatalysts exhibited high visible-light responsive photocatalytic activity. To achieve the cyclic utilization of CQDs-Bi20TiO32, the novel flexible CQDs-Bi20TiO32/PAN fiber membranes were prepared by a simple coaxial electrospinning technique. It was found that the CQDs-Bi20TiO32 photocatalyst could be firmly and uniformly fixed on the surfaces of electrospun fibers and the composite fiber membranes possessed the hierarchical macro- and mesoporous structure. The loaded CQDs-Bi20TiO32 endowed the composite fiber with an obvious photocatalytic activity for the degradation of the herbicide isoproturon under visible light irradiation. Among these samples, S3 at photocatalyst dosage 15 w/v% had the highest degradation efficiency for isoproturon. Meanwhile, the core-shell structured inorganic-organic hybrid fiber membranes have a significant advantage in the recyclability for photocatalyts. The flexible CQDs-Bi20TiO32/PAN electrospun fiber membranes would have potential applications in efficient removal of organic contaminants.Download high-res image (165KB)Download full-size image
Co-reporter:Ruyi Xie, Linping Zhang, Hong Xu, Yi Zhong, Xiaofeng Sui, Zhiping Mao
Chemical Engineering Journal 2017 Volume 310, Part 1(Volume 310, Part 1) pp:
Publication Date(Web):15 February 2017
DOI:10.1016/j.cej.2016.10.089
•Nanowire photocatalyst Bi20TiO32 was modified by carbon quantum dots (CQDs).•CQDs/Bi20TiO32 showed much higher photocatalytic activity than pure Bi20TiO32.•The introduction of CQDs accelerated separation of photo-induced charge carriers.•O2− and h+ were the dominant active species to decompose isoproturon.•PAN-CQDs/Bi20TiO32 nanofiber mats exhibited good recyclability and high stability.To achieve the efficient utilization of solar light energy, novel carbon quantum dots (CQDs) modified Bi20TiO32 photocatalysts were prepared with different CQDs contents. The obtained photocatalysts were characterized by XRD, FT-IR, XPS, SEM, HRTEM, photoluminescence (PL) spectra, transient photocurrent and electrochemical impedance spectroscopy (EIS). The results showed that the CQDs were uniformly deposited on the surface of Bi20TiO32. The as-prepared CQDs/Bi20TiO32 composites were capable of utilizing both the visible and near-infrared light due to the active role of the carbon nanodots as up-converting photo-sensitizers. By the LC–MS-MS analysis, the herbicide isoproturon molecular could be firstly degraded to several intermediates and then completely mineralized. The CQDs/Bi20TiO32 photocatalysts with a CQDs content of 1% exhibited the optimum photocatalytic activity and could degrade 98.1% of isoproturon within 48 h. Its degradation rate constant was approximately 4.3 times higher than that of pure Bi20TiO32. The main active species in the photo-degradation process was h+ and O2−. To further study the recycle ability of CQDs/Bi20TiO32 photocatalyst, the PAN supported CQDs/Bi20TiO32 nanofiber mat was prepared by coaxial electrospinning method. The composite nanofiber materials showed good photocatalytic activity and recyclability, which had potential applications in water/air purification field and biochemical protective clothing.Hierarchical carbon quantum dots/Bi20TiO32 with enhanced photoactivity towards the degradation of isoproturon.Download full-size image
Co-reporter:Ming Lu;Lanqian Li;Ruyi Xie;Zhenyun Zhao
Cellulose 2017 Volume 24( Issue 2) pp:1099-1106
Publication Date(Web):09 December 2016
DOI:10.1007/s10570-016-1152-2
Magnetic nanoparticles were synthesized and embedded into the surface of cotton fibers via surface micro-dissolution method using NaOH/urea aqueous solution as dissolving agent, magnetic nanoparticles as the filler, and H2SO4/Na2SO4 aqueous solution as the coagulant. The magnetic nanoparticles and cotton fabrics were systematically studied by means of scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, thermal gravity, vibrating sample magnetometry, Fourier transform infrared spectroscopy, and tensile testing. The results indicated that treated cotton fabrics contained about 12 wt% Fe3O4 and possessed durable magnetic response. Without using any adhesion agents, this surface micro-dissolution treatment provides a simple and green method to introduce nanoparticles into superficial layers of natural cotton fibers.
Co-reporter:Hongchen Liu, Liduo Rong, Bijia Wang, Ruyi Xie, Xiaofeng Sui, Hong Xu, Linping Zhang, Yi Zhong, Zhiping Mao
Carbohydrate Polymers 2017 Volume 176(Volume 176) pp:
Publication Date(Web):15 November 2017
DOI:10.1016/j.carbpol.2017.08.085
•A cellulose-based hydrogel was prepared under physiological condition.•The hydrogel displayed stability in PBS (pH = 7.4) condition for 3 days.•The cellulose-based hydrogel showed dual pH and redox responsiveness.•This protocol can also be applied to prepare other polysaccharide hydrogels.A cellulose-based multi-responsive hydrogel was prepared by the facile incorporation of enamine and disulfide bonds in the same system at physiological pH. The cellulose hydrogel was obtained by simply mixing aqueous solutions of cellulose acetoacetate (CAA) and cystamine dihydrochloride (CYS) at room temperature. The internal morphology, structure, and mechanical properties of the cellulose hydrogel were characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) and Raman spectroscopies, nuclear magnetic resonance (NMR), and water retention, porosity, and rheology measurements. The cellulose hydrogel showed reversible sol–gel transitions in response to both pH and redox triggers. In addition, it displayed good stability under physiological conditions. Gels loaded with small molecules showed variable release properties in response to pH or redox stimuli. The preparation protocol presented here could be used to fabricate other multi-responsive polysaccharide hydrogels.
Co-reporter:Hongchen Liu;Xiaofeng Sui;Hong Xu;Linping Zhang;Yi Zhong
Macromolecular Materials and Engineering 2016 Volume 301( Issue 6) pp:725-732
Publication Date(Web):
DOI:10.1002/mame.201600042
Co-reporter:Shuo Wang, Xiaofeng Sui, Yingzhan Li, Jiawei Li, Hong Xu, Yi Zhong, Linping Zhang, Zhiping Mao
Polymer Degradation and Stability 2016 Volume 128() pp:22-28
Publication Date(Web):June 2016
DOI:10.1016/j.polymdegradstab.2016.02.009
The organosilicon functionalized cyclotriphosphazene (N3P3[NH(CH2)3Si(OC2H5)3]6) was synthesized and characterized by nuclear magnetic resonance (NMR) and Fourier transform infrared spectra (FTIR), then it was applied to cotton fabrics through a convenient pad-dry-cure process to fabricate flame retardant coating with different add-on values. The coating on cotton fabrics was confirmed by the scanning electron microscopy (SEM). Excellent flame retardancy was found from limited oxygen index (LOI) and vertical burning test. The coating induced an earlier decomposition of cellulose, enhanced the formation of the stable char and significantly reduced the heat release rate. Moreover, flame retardancy of the coated fabrics did not change significantly after 30 soaping cycles.
Co-reporter:Ming Lu;Ruyi Xie;Zulan Liu;Zhenyun Zhao;Hong Xu
Journal of Applied Polymer Science 2016 Volume 133( Issue 32) pp:
Publication Date(Web):
DOI:10.1002/app.43601
ABSTRACT
Recently, great efforts have been made to gain highly conductive fabrics for smart textiles and flexible electromagnetic shielding materials. Different from the conventional chemical synthesis method, fibrillar polypyrrole was synthesized on the cotton fabrics via a simple chemical polymerization process with micelles of cationic surfactant (cetyltrimethylammonium bromide, CTAB) as soft template. The modified cotton fabric exhibited excellent electrical conductivity and electromagnetic interference shielding effectiveness due to the formation of fibrillar polypyrrole on the fiber surface. Electrical conductivity of fabric surface were studied by four-probe resistivity system. The highly conductive fabric with surface conductivity of 5.8 S cm−1 could be obtained by changing cationic surfactant concentration. The electromagnetic interference shielding effectiveness (EMI SE) of the modified fabrics was evaluated by the vector network analyzer instrument. Compared with the sample without using surfactant, the EMI SE value of PPy-coated cotton fabrics increased by 28% after using 0.03 M CTAB as soft template. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43601.
Co-reporter:Dawei Fu, Linping Zhang, Ruyi Xie, Hong Xu, Yi Zhong, Xiaofeng Sui, Zhiping Mao
Journal of Photochemistry and Photobiology A: Chemistry 2016 Volume 329() pp:18-25
Publication Date(Web):1 October 2016
DOI:10.1016/j.jphotochem.2016.06.012
•rGO/Bi20TiO32 was prepared by a facile in suit hydrothermal method.•The activity of rGO/Bi20TiO32 was enhanced under visible-light.•rGO/Bi20TiO32 showed strong optical absorption and rapid charge separation.The photocatalytic performance of pure Bi20TiO32 was restricted by the fast charge recombination. Considering the high carrier mobility of reduced graphene oxide (rGO), a series of rGO/Bi20TiO32 composites were successfully fabricated by a facile in suit method with the aim to promote the charge separation. Inspiringly, 2% rGO/Bi20TiO32 composite showed much higher photocatalytic activity for the degradation of non-biodegradable Rhodamine B (RhB) under visible-light irradiation, which was 10 times higher than that of pure Bi20TiO32. The enhanced photocatalytic performance of rGO/Bi20TiO32 composites could be attributed to their stronger optical absorption in the visible-light region and rapider separation efficiency of the photogenerated electron-hole pairs. The underlying photocatalytic mechanism was revealed through the Photoluminescence spectra and free radical capture experiment. This work provided a rational design for the development of high efficient visible-light photocatalysts.
Co-reporter:Jiawei Li;Feng Pan;Xiong Zeng;Hong Xu;Linping Zhang;Yi Zhong;Xiaofeng Sui
Journal of Applied Polymer Science 2015 Volume 132( Issue 44) pp:
Publication Date(Web):
DOI:10.1002/app.42711
ABSTRACT
Para-allyl ether phenol derivative of cyclophosphazene (PACP) was prepared and used as a filler to modify the flame-retardant properties of poly(ethylene terephthalate) (PET) by melting-blending. The mechanism of flame-retardant was discussed and the influences of flame-retardant contents to the mechanical properties were studied. The results revealed that the incorporation of only 5 phpp PACP (0.37 wt % phosphorus containing) into PET matrix can distinctly increase the flame retardancy of PET/PACP composition, and it has a little effect on the mechanical properties of PET. The high flame-retardant performance of PET/PACP composite was attributed to the combination of condensed-phase flame retardant and gas-phase flame retardant. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42711.
Co-reporter:Shuaijun Fang, Wei Wang, Xili Yu, Hong Xu, Yi Zhong, Xiaofeng Sui, Linping Zhang, Zhiping Mao
Materials Letters 2015 Volume 143() pp:120-123
Publication Date(Web):15 March 2015
DOI:10.1016/j.matlet.2014.11.102
•ZnO:(Al, La)/PAN nonwovens were firstly prepared by electrospinning.•The infrared emissivity of nonwovens at the waveband 8–14 μm was low to 0.793.•This material was applied in military camouflage field.Polyacrylonitrile (PAN) nonwovens with infrared stealthy performance were successfully prepared via electrospinning. ZnO:(Al, La) dispersion mixed with PAN solution, then the solution was electrospun to obtain ZnO:(Al, La)/PAN nanocomposite. The infrared stealthy performance of ZnO:(Al, La)/PAN nonwovens was characterized by IR-2 dual-band infrared emissivity measuring instrument and thermal infrared imaging system. Results showed that the infrared emissivity of nonwoven fabric at the waveband 8–14 µm was low to 0.793, which could be matched in the surroundings of withered grass or rock under the non-sunshine time.
Co-reporter:Tong Xu;Linping Zhang;Yi Zhong
Journal of Applied Polymer Science 2014 Volume 131( Issue 1) pp:
Publication Date(Web):
DOI:10.1002/app.39608
ABSTRACT
Polyimide (PI) fabric was coated with composite films composed of poly(N-benzyloxycarbonyl-3,4-dihydroxyphenylalanine) (PNBD) and montmorillonite (MMT), prepared via layer-by-layer assembly. Three coating recipes (changed by altering the concentration of PNBD solution) were used to study the growth of thin films. Scanning electron microscope showed that, after 20 times standard washing, PNBD-MMT film still coated on PI fiber, while MMT film coated on PI had been almost washed off. Thermogravimetric analysis indicated that, in nitrogen atmosphere at 900°C, the residue of uncoated PI was 36.62%, after 20 times standard washing, residue of PNBD-MMT coated PI (53.80%) was higher than that of MMT coated PI (50.08%). Vertical flame testing showed that the burning length of PNBD-MMT coated PI (7 mm) was much shorter than that of uncoated PI (30 mm) and MMT coated PI (17 mm) after 20 times standard washing. These results demonstrated the excellent flame retardancy and durability of PNBD-MMT film coated PI fabric. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39608.
Co-reporter:Jiawei Li, Feng Pan, Hong Xu, Linping Zhang, Yi Zhong, Zhiping Mao
Polymer Degradation and Stability 2014 110() pp: 268-277
Publication Date(Web):
DOI:10.1016/j.polymdegradstab.2014.08.027
Co-reporter:Zhiping Mao, Wei Wang, Ying Liu, Linping Zhang, Hong Xu, Yi Zhong
Thin Solid Films 2014 Volume 558() pp:208-214
Publication Date(Web):2 May 2014
DOI:10.1016/j.tsf.2014.02.055
•The infrared stealth cotton fabric was coated by W-doped VO2 as the filler.•The emissivity of coated fabric was 0.752.•The abrupt amount in the emissivity of coated fabric was 0.2 in the phase transition.•The infrared stealth cotton fabric was adaptable to the surroundings spontaneously.The infrared stealth fabric was prepared using W-doped VO2 (M) paints by the coating technology. The thermochromic W-doped VO2 (M) was synthesized through hydrolysis method and two-step calcinations under N2 atmosphere. The powders were evaluated by scanning electron microscopy, X-ray diffraction patterns and differential scanning calorimetry. The infrared emissivity of coated cotton fabric was measured by IR-2 Infrared Emissometer, which was as low as 0.752. The low infrared radiation intensity for coated cotton fabric was detected using the infrared imaging systems above the phase temperature of W-doped VO2 (M). The results indicated that the W-doped VO2 (M) thin films exhibited thermal infrared stealth performance, which could adapt to the surroundings spontaneously.
Co-reporter:Hui Ma, Hong Xu, Jielei Qu, Wenbo Bian, Yi Zhong, Narendra Reddy, Yiqi Yang, Zhiping Mao
Composites Science and Technology 2013 Volume 87() pp:118-125
Publication Date(Web):18 October 2013
DOI:10.1016/j.compscitech.2013.08.007
Modified vermiculites (MVMTs) that self-assembled into fiber or nacre-like structures were fabricated by covalent bonding with hexamethylene adipamide (HA) during in situ polymerization. Unlike previous researches where self-assembled silicates have been fabricated via physical interactions, covalent bonding of vermiculites demonstrated in this research provided substantially higher mechanical properties and thermal resistance to the assembled materials. In addition, the shape and size of the self-assembled structures could be controlled by varying the amount of coupling agent and the modulus of the fiber-like assemblies could be controlled by heating. X-ray Photon Spectroscopy proved the covalent attachment of the HA onto vermiculites. At low concentrations (11%) of coupling agent, the MVMTs self-assembled into fiber like structure and into nacre-like structures at a coupling agent concentration of 17% thereby enabling us to control the shape and size of the self-assemblies. Atomic force microscope measurements showed that the elastic modulus of the self-assemblies were about 17–18 GPa, compared to the modulus of 0.3 and 1.5 GPa for the pure polymer and unmodified clay, respectively. The ability to covalently bond and control the self-assemblies and the resulting high performance properties of the self-assemblies could be useful to develop materials for various applications.
Co-reporter:Linping Zhang, Yingying Jiang, Hui Ma, Xiaoyan Zhang, Hong Xu, Yi Zhong, and Zhiping Mao
Industrial & Engineering Chemistry Research 2013 Volume 52(Issue 10) pp:3607-3612
Publication Date(Web):February 20, 2013
DOI:10.1021/ie302441r
Al(OH)3 thin films were assembled on anionic polysulfonamide (PSA) fabrics by electrostatic self-assembly method to improve the mechanical, heat insulation, and flame retardant properties of PSA fabrics. PSA fabric surface was modified with a chemical reaction to build-up anionic charge known as anionization. Then a homogeneous Al(OH)3 film was deposited in the fiber interstices after the treatment of Al(OH)3 nanoparticles by electrostatic self-assemblies. The scanning electron microscopy (SEM) and X-ray powder diffraction (XRPD) were used to verify the presence of deposited Al(OH)3 thin films. Tensile strength, heat insulation, and flame retardancy of PSA fabrics were analyzed before and after the treatment of Al(OH)3 thin films. It was proved that the heat insulation and flame retardancy of PSA fabrics could be improved by Al(OH)3 films additive through electrostatic self-assembly process.
Co-reporter:Hui Ma, Zhixiang Chen, Zhiping Mao
Vacuum 2013 Volume 95() pp:1-5
Publication Date(Web):September 2013
DOI:10.1016/j.vacuum.2013.02.001
Controlled magnesium hydroxide particles were assembled successfully on the surface of cotton fibers for the improvement of flammability and thermal stability of cotton/magnesium hydroxide composites. Unlike previous researches where magnesium hydroxide particles have been blended into polymer matrix, self-assembly of particles onto the fiber surface demonstrated in this research provided substantially excellent properties. The morphology, structure and properties of cotton/magnesium hydroxide composites were characterized. Here, the fibers exhibited a swelling surface after the urea-modification, resulting in the more amounts of magnesium hydroxide crystals growing. Without the presence of sodium chloride, the particles self-assembled into lamellar-like structure on the surface of cotton fibers and into rod-like structures with the presence of sodium chloride thereby enabling us to control the growth of the particles. The vertical flammability test showed that the introduction of sodium chloride resulted in the change of morphology of magnesium hydroxide crystals, which had the important effect on the fire-proofing properties of cotton/magnesium hydroxide composites. The weight loss of origin fabrics, citric acid-modified cotton fabrics with Mg(OH)2 crystals grew with salts and urea/citric acid-modified cotton fabrics with Mg(OH)2 crystals grew with salts were 81.5%, 57.4% and 48.9% respectively when heated to a temperature of 500 °C.Highlights► Controlled magnesium hydroxide particles were obtained on the cotton fibers. ► Magnesium hydroxide could be assembled into lamellar- and rod-like structures. ► Fire-proofing properties of the cotton/magnesium hydroxide were improved. ► Thermal stability of the cotton/magnesium hydroxide was elevated.
Co-reporter:Linping Zhang;Peiju Zhu;Hong Xu;Yi Zhong
Journal of Inorganic and Organometallic Polymers and Materials 2013 Volume 23( Issue 3) pp:546-552
Publication Date(Web):2013 May
DOI:10.1007/s10904-012-9811-8
This research was primarily focused on investigating the possibility of the production of novel organo-soluble polyamides with coordination metal complex units in the main chain. Using a copper(II) coordination complex as a monomer, a novel Cu(II)-containing polyamide was synthesized by polycondensation with m-phenylenediamine. The obtained polyamide with Cu(II) ions in the main chain had an inherent viscosity of 0.20 dL/g, which indicated that it was a low molecular weight polymer. Then the p-phthalic acid monomer was introduced to the above synthesis system to create a Cu(II)-containing co-polyamide with a higher molecular weight. The subsequent addition of p-phthalic acid resulted in the formation of a series of co-polyamides with different contents of the Cu-complex in the main chain, which had higher inherent viscosity. The structures of the Cu(II)-containing polymers were characterized by ICP and 1H-NMR. The prepared co-polyamides had increased solubility in organic solvents. It also revealed that the UV absorption properties of co-polyamides were enhanced significantly by the incorporation of Cu(II) ions into the polymer chain.
Co-reporter:Tong Xu;Yi Zhong;Yan liu;Hong Yu
Journal of Thermal Analysis and Calorimetry 2013 Volume 111( Issue 1) pp:27-33
Publication Date(Web):2013 January
DOI:10.1007/s10973-012-2549-2
In this study, polyimide (PI) fabric was coated with montmorillonite (MMT) which performed as a kind of flame retardant. Thermogravimetric analysis showed that PI coated with MMT left as much as 69 % char after heating to 700 °C, about 15 % more than uncoated PI fabric. Cone calorimeter testing (heat flux: 60 kW m−2) showed that coated fabric reduced the total heat release and showed resistance to degradation from direct flame. Post-burn residues of samples were examined with SEM and revealed that the weave structure and fiber shape in all coated fabrics were preserved. In addition, heat-insulting test showed that the temperature difference of coated PI could reach 400 °C after 10 min at 800 °C. These results demonstrate that MMT coating is relatively effective for improving flame-retardant behavior to PI fabric.
Co-reporter:Xuan Zhang, Yi Zhong, Zhi-Ping Mao
Polymer Degradation and Stability 2012 Volume 97(Issue 8) pp:1504-1510
Publication Date(Web):August 2012
DOI:10.1016/j.polymdegradstab.2012.05.006
The aim of this work was to study the effect of hexakis(4-nitrophenoxy) cyclotriphosphazene (HNCP), which was found to be a highly efficient and intumescent flame retardant, on the thermal properties and flame retardancy of poly(ethylene terephthalate) (PET). HNCP was synthesized for use as flame retardant. PET/HNCP composites were prepared by melt blending. Three levels of HNCP (5%, 10% and 15%) were considered for the blends. Thermal stability of PET/HNCP systems was studied by thermogravimetric analysis, and the results showed that the addition of HNCP could improve char formation of this system both in nitrogen and in air atmosphere. It was found that the blends could pass UL-94 V-0 just containing 5% of HNCP. The Py-GC/MS analytical results indicated that introducing HNCP into PET would prevent the polymer pyrolysis during heating. The morphology and structure of the charred residue of these samples were evaluated by SEM and FTIR respectively. Results demonstrated that the char of PET/HNCP blends with a continuous outer surface and porous internal structure provided a good barrier to improve the thermal behaviours and decrease combustion properties of the composites during burning.
Co-reporter:Ying Pan, Guangting Han, Zhiping Mao, Yuanming Zhang, Hui Duan, Jiancheng Huang, Lijun Qu
Carbohydrate Polymers 2011 Volume 85(Issue 1) pp:188-195
Publication Date(Web):22 April 2011
DOI:10.1016/j.carbpol.2011.02.013
Lotus fiber is a natural cellulose fiber isolated from lotus petiole. Botanically, the fiber is the thickened secondary wall in xylem tracheary elements. In order to obtain essential information for the preparation and processing of lotus fibers, the fine structure and properties of lotus fibers were investigated by the aid of transmission electron microscopy (TEM), confocal laser scanning microscopy (CLSM), atomic force microscopy (AFM), X-ray diffraction (XRD), and so on. The results show that lotus fibers display a rough surface topography and an internal structure different from common plant fibers. The percent crystallinity and preferred orientation of crystallites in lotus fibers are 48% and 84%, respectively. Considering the average breaking tenacity and Young's modulus, lotus fibers are similar to cotton. The elongation of lotus fibers is only about 2.6% while their moisture regain is as high as 12.3%.
Co-reporter:Hong Xu, Xue Shi, Hui Ma, Yihang Lv, Linping Zhang, Zhiping Mao
Applied Surface Science 2011 Volume 257(Issue 15) pp:6799-6803
Publication Date(Web):15 May 2011
DOI:10.1016/j.apsusc.2011.02.129
Abstract
Silver nanoparticles (AgNPs) have been known to have powerful antibacterial activity. In this paper, in situ generation of AgNPs on the surface of dopamine modified cotton fabrics (dopa-cotton/AgNPs) in aqueous solution under room temperature is presented. X-ray photoelectron spectroscopy (XPS) and field emission scanning electron microscope (FE-SEM) were used to analyze the surface chemical composition and the morphology of the modified cotton fabrics, respectively. The results indicated that the surface of cotton fabrics was successfully coated with polydopamine and AgNPs. The cotton fabrics with AgNPs showed durable antibacterial activity.
Co-reporter:He Huang;Dan Zhang;Weidong Yu;Haojing Yan
Journal of Applied Polymer Science 2009 Volume 112( Issue 1) pp:123-128
Publication Date(Web):
DOI:10.1002/app.28457
Abstract
Poly(N-isopropylacrylamide-co-sodium acrylate) gels with N,N-methylene bisacrylamde (BIS) as crosslinker were prepared by free radical polymerization method at the temperature of 35°C, which was just around the lower critical solution temperature (LSCT) of the hydrogels. The gels synthesized at 35°C demonstrated strong swellability and fast responseability when compared with the gels synthesized at the temperature of 0 and 18°C (below the LCST) and 50 and 80°C (above the LSCT). The response rate and swelling behavior of poly(N-isopropylacrylamide-co-sodium acrylate) gels was investigated and characterized by the temperature-dependent swelling ratio and swelling and deswelling kinetics. The swelling behavior of the gels indicated that the synthesis temperature was the main factor when the swellability concerned and also had effect on the responseability of the resulting hydrogels. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Co-reporter:Zhiping Mao, Qiuping Shi, Linping Zhang, Huantian Cao
Thin Solid Films 2009 Volume 517(Issue 8) pp:2681-2686
Publication Date(Web):27 February 2009
DOI:10.1016/j.tsf.2008.12.007
ZnO nanoparticles were in-situ grown on SiO2 coated cotton fabric through hydrothermal method. A following hot water treatment at 100 °C or higher could transform the morphology of the ZnO nanoparticles on the surface of cotton fabric from sphere and rod to much smaller diameter needle shape through a recrystallization process. After water treatment at 100 °C or higher, the cotton fabric was covered with approximately 24 nm diameter needle-shaped ZnO nanorod and had an excellent UV-blocking property with UV protection factor value over 50. The effects of temperature and time of hot water treatment on the size and crystalline perfection of ZnO nanorod and the UV-blocking property were also studied.
Co-reporter:Ying Pan, Guangting Han, Zhiping Mao, Yuanming Zhang, Jiancheng Huang, Lijun Qu
Aquatic Botany (August 2011) Volume 95(Issue 2) pp:167-171
Publication Date(Web):August 2011
DOI:10.1016/j.aquabot.2011.05.002
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