CHEMICAL ENGINEERING JOURNAL
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2020
·
IF 10.652
Kai Wu,Yongzheng Zhang,Feng Gong,Dingyao Liu,Chuxin Lei,Qiang Fu
Polymer-based 1D materials with excellent axial thermal conductivity and electrical resistivity are highly demanded for thermal management in wearable electronics. In the last decades, boron nitride nanosheets (BNNS) were commonly introduced into polymer-based materials for improving their thermal conductivity, while they were mainly focused on 2D papery film or 3D bulk composite materials. 1D polymer/BNNS composite filaments are far from a rapid development, and their axial thermal conductivity is still restricted to a low value (<5 W/m K), mainly because of insufficient orientation and low addition of BNNS. Herein, a highly thermo-conductive but electrically insulating regenerated cellulose (RC)/BNNS composite filament is fabricated by a volume-confinement self-assembled method in a wet-spinning procedure, in which large-sized BNNS are mandatorily confined within the limited region among adjacent RC nanofibers at BNNS loading of 60 wt%. Attributed to its highly anisotropic conformation, the as-prepared composite filament exhibits an ultra-high thermal conductivity of 9.22 W/m K, about 4.5-fold of non-confined RC/BNNS counterpart. After being weaved into a textile and integrated with a thermoelectric generator (TEG), it enables TEG to efficiently harvest energy from body heat and continuously self-power some wearable electronics, demonstrating a significant proof of concept for its extraordinary wearable thermal management applications.
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高影响因子
Journal of Cleaner Production
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2020
·
IF 7.246
Xingguo Wang,Wenjia Wang,Shuheng Wang,Yufan Yang,Hongfei Li,Jun Sun,Xiaoyu Gu,Sheng Zhang
The demand for eco-friendly poly (lactic acid) (PLA) nonwovens grows at a high rate in the past several decades, however, only a little attention has been received for flame retardant PLA nonwoven fabrics. In this work, a novel halogen-free self-intumescent polyelectrolyte tris (hydroxymethyl)-aminomethane polyphosphate (APTris) was synthesized by reacting ammonium polyphosphate with tris (hydroxymethyl) aminomethane, and was then used to improve the fire resistance of PLA nonwovens via a dip-nip process. The flammability characterization indicated the limiting oxygen index value was increased to 30.0% from 18.3%, and the damaged area in the vertical burning test was reduced by about 87.0% by the presence of APTris. The cone calorimeter test results revealed that the peak heat release rate and total heat release of the treated sample were decreased by 41.0% and 28.2% respectively compared with that of the control PLA nonwoven sample. The char residue was increased to 12.3 from 1.7 wt % at 800 °C. It is suggested that the dense char barrier formed at the presence of APTris prevents heat, smoke, and gas transfer, and hence enhance thermal dilatability and flame retardancy of PLA nonwovens. This simple sustainable halogen-free treatment has great potential to produce cleaner commercialized flame-retardant PLA nonwovens.
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PubMed
高影响因子
DALTON TRANSACTIONS
·
2020
·Vol. 49
·期 32
·11226-11237
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IF 4.174
Zhihao Zhang,Xinjuan Li,Zhongying Ma,Haozhe Ning,Dan Zhang,Yuhua Wang
There are still some key problems in the process of the flame retardant treatment of poly vinyl alcohol (PVA): poor compatibility, deteriorating mechanical properties and potential toxicity to human health and environment. To solve these issues, a green and eco-friendly bio-based polyelectrolyte complex (PEC) formed by chitosan and phytic acid was designed to enhance the flame retardant and mechanical properties of PVA by a facile ultrasonic-assisted solution blending method. Moreover, the mechanical and flame retardant properties could be regulated by varying the ratio of each component in the PEC. Thermogravimetric analysis (TGA) indicated that after the introduction of PEC, PVA/PEC composites maintained better thermal stability and char formation ability. Besides, when the addition of PEC reached 20 wt%, the limited oxygen index (LOI) value of cured PVA increased from 18% to 25.9%, 30.8% and 35.6% for PVA/20(2 : 1) PEC, PVA/20(1 : 2) PEC and PVA/20(1 : 8) PEC, respectively. Moreover, UL-94 V-0 rating was achieved except for the PVA/20(2 : 1) PEC. Compared with pure PVA, the peak heat release rate (pHRR) and the total heat release (THR) of PVA/20(1 : 8) PEC demonstrated a sharp decrease by 69.9% and 45.5%, respectively, in the microscale combustion calorimeter measurements (MCC). These results indicate that PEC can endow PVA with excellent flame retardancy. Furthermore, the microscopic investigations on char residues of all samples by scanning electron microscopy, Fourier transform infrared spectra and Raman spectroscopy revealed the possible flame retardant mechanisms in condensed and gaseous phases. In addition, PVA/PEC composites have better mechanical properties owing to their harder backbones of chitosan, formation of phosphonate bonds and the PVA molecular chain movement blocked by PEC. As a result, the facile processing technology and eco-friendly flame retardants are expected to be applied in practice.
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高影响因子
Sustainable Energy & Fuels
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2020
·Vol. 4
·期 8
·3926-3933
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IF 5.503
Tao Long,Fancheng Meng,Bin Xu,Yixin Zhao,Weilin Liu,Xiangfeng Wei,Lianxi Zheng,Jiehua Liu
Porous carbon structures are considered as desirable electrode materials for Li–S batteries due to their flexible texture, high surface areas, and good conductivities. However, polymer carbonized materials usually suffer from limited electrical conductivity that will finally restrain the battery's electrochemical performance. Herein, in this paper, polyaniline (PANI) hydrogels are firstly synthesized on a template of conductive N-doped carbon nanotubes (NCNTs) via a solution process. After carbonization and activation treatments, the composite materials reveal a highly porous carbon (HPC) structure interwound by NCNT wires, demonstrating a high specific surface area of 1861 m2 g−1 and a high electrical conductivity. After further incorporation of elemental sulfur, the resultant NCNTs@HPC/S cathode exhibits excellent electrochemical properties with a superior initial capacity of 1506 mA h g−1 at 0.2C, a stable capacity of 613 mA h g−1 after 250 cycles, and an obviously improved rate performance. This work suggests a feasible and efficient approach to fabricate carbon-based high-performance Li–S battery cathodes.
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高影响因子
Materials
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2020
·Vol. 13
·期 9
·2033
·
IF 3.057
Yongzhen Lei,Long Mao,Jin Yao,Zhihan Li
Poly(lactic acid) (PLA) represents one of the most promising and attractive bio-based polymers for green packaging. However, toughness, gas barrier and antibacterial properties of pure PLA films cannot compete with those of traditional petroleum-based active packaging plastics. To fill this gap, utilization of excellent chelating properties of phytic acid (PA), functionalized layered double hydroxides (LDHs@PA-Cu(II)) was firstly synthetized via facile deposition and chelation of one-step assembled PA-Cu(II) coordination compounds on the surface of layered clay. Furthermore, LDHs@PA-Cu(II)/PLA nanocomposites were prepared by blending LDHs@PA-Cu(II) and pure PLA via solution casting evaporation process. After adding only 1 wt % LDHs@PA-Cu(II), elongation at break and tensile strength increase by 53.0% and 18.9%, respectively, and the oxygen relative permeability decreases by 28.0%. Due to the strong interface interaction and heterogenous nucleation, the reinforcement effect of LDHs@PA-Cu(II) at low loadings is remarkable. Meanwhile, owing to the antibacterial activity of PA-Cu(II) coatings, the antibacterial rate (against Escherichia coli) of LDHs@PA-Cu(II) exceeds 99.99%. Furthermore, the corresponding LDHs@PA-Cu(II)/PLA nanocomposites also show outstanding antibacterial properties, which will be a promising candidate for active packaging application.Keywords:layered double hydroxides;phytic acid;antibacterial activity;polylactic acid;barrier properties
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高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2020
·
IF 5.162
Chanchal Kumar Kundu,Zhiwei Li,Xiaohong Li,Zhijun Zhang,Yuan Hu
A plant derived bio-macromolecule namely lignin (L) and a green phosphorus compound like phytic acid (PA) were functionalized with graphene oxide (GO) and subsequently, used to enhance the flame retardant properties of polyamide 66 (PA66) fabrics in a one pot deposition method. Meanwhile, we also considered pure phytic acid and one more bio-derived charring agent like chitosan (CS) to formulate a series of GO-based flame retardant finishing by altering the applied compounds in the formulation. The applied finishing with a minimum loading % (i.e., less than 10%) rarely altered the physical properties (i.e., color, handle and tensile strength , etc.) of treated textiles while provided enhanced thermal stability and added flame retardancy. Thus, a significant increase in limiting oxygen index (LOI) by 27% was received for the GO-lignin and GO-phytic acid modified fabric sample (i.e., PA66-A), indicating the supremacy of graphene-based compound. Furthermore, a substantial reduction in the peak heat release rate (pHRR) by 25% was also noticed for the fabric sample treated with GO-lignin, chitosan and phytic acid (i.e., PA66-D). Additionally, the as prepared finishing exhibited a considerable level of wash durability as a maximum reduction of pHRR by 17% was retained even after 5 washing cycles.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
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2020
·
IF 10.652
Wenwen Guo,Xin Wang,Jiali Huang,Yifan Zhou,Wei Cai,Junling Wang,Lei Song,Yuan Hu
A flame-retardant and superhydrophobic coating was deposited on cotton fabrics using a simple two-step spraying method. In detailed, the first step involved flame-retardant layer consisted of alkylammonium functional silsesquioxane (A-POSS)/phytic acid (PA) complex, while the second step generated superhydrophobic layer that was composed of hierarchical structured titanium oxide@polydimethylsiloxane (TiO 2 @PDMS) composite. The influence of the components’ loading in the coating on flame-retardant, thermal and wetting properties of the coated cotton fabrics was investigated systematically. The optimized coated cotton sample denoted as C3-PDMS-TiO 2 was screened through limiting oxygen index (LOI), UL-94 flammability test, cone calorimetry measurement and water contact angle (WCA). Specifically, C3-PDMS-TiO 2 sample showed self-extinguishing behavior in the vertical burning test, as well as a significantly enhanced LOI to 29% from 18% for pristine cotton fabrics. Furthermore, the peak heat release rate (PHRR) and the total heat release (THR) values of C3-PDMS-TiO 2 were significantly declined by 70% and 41%, respectively, compared to those of pristine cotton fabrics. Additionally, C3-PDMS-TiO 2 exhibited super self-cleaning ability as a consequence of its superhydrophobic surface. Furthermore, C3-PDMS-TiO 2 was applied for water-oil separation, and exhibited robust ability even in strong acid- or alkali-oil mixtures. The C3-PDMS-TiO 2 fabrics also displayed super abrasion resistance (WCA > 139° after 50 abrasion cycles) and washing durability (self-extinguishing after 5 laundering cycles). This facile finishing technique has great potentials in application as multifunctional advanced textiles.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Zhe Wang,Huimin Hu,Liqin Huang,Fanyu Lin,Shuang Liu,Tong Wu,Njud Saleh Alharbi,Samar Omar Rabah,Yuexiang Lu,Xiangke Wang
Developing convenient and rapid method for eliminating uranium from massive contaminated water under emergency conditions is highly needed. Herein we developed a novel chemical precipitation strategy based on graphene aerogel capsulated with the degradation products of phytic acid (PAGA). With hydrothermal treatment, graphene oxide was twisted and reduced to generate aerogel, acting as an encapsulator. At the same time, phytic acid (PA) was degraded into various compounds and capsulated into graphene aerogel with a high loading capacity of 85 g/g. After adding PAGA into uranium contaminated water, the degradation products were released out of GA skeleton to combined with uranium and form sediments. The elimination capacity reached up to 3550 mg/g within 40 min and the obtained sediments possessed good stability in the following 72 h. PAGA capsule also presented high removal rate in various water systems, making it a kind of versatile material in the elimination of uranium under emergency conditions.
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高影响因子
PROGRESS IN ORGANIC COATINGS
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2020
·
IF 4.469
Mohammad Ziaur Rahman,Chanchal Kumar Kundu,Hafezeh Nabipour,Xin Wang,Lei Song,Yuan Hu
The layer by layer (LBL) deposition of chitosan/melamine/urea (CS/ME/UREA) and phytic acid (PA) onto the acrylic acid (AA) grafted Polyamide 6.6 (PA6.6) fabrics including a pad-dry-cure treatment with chitosan/graphene oxide (CS/GO) nanocomposites were considered to improve the hydrophilicity and durable flame retardancy. Obtained results indicated that these hybrid coatings could significantly improve the flame retardancy as the limiting oxygen index (LOI) value reached up to 25 % from 18.5 % and could completely stop the melt dripping where the fabric sample with two bilayers deposition and simultaneously treated with CS/GO nanocomposite (PA6.6-g-AA-2BL-CS/GO) achieved a V-1 rating. A 2BLs deposited hybrid coating (i.e., PA6.6-g-AA-2BL-CS/GO) could decrease the peak heat release rate (pHRR) by 47.1 %; whereas a maximum reduction of pHRR by about 56 % was achieved for 5BLs deposition. Moreover, a considerable improvement in thermal stability and char yield% were also realized in the thermogravimetric analysis (TGA) test. Furthermore, the as-prepared hybrid coatings imparted better hydrophilicity as a 2BLs deposition along with pad-dry-cure treatment by CS/GO could boost up the hydrophilicity of the treated fabrics further compared to the only 2BLs deposited fabric sample. In addition, the application of CS/GO nanocomposite could improve the stability of this coating and able to stop the dripping tendency even after 10 laundering cycles as well.
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高影响因子
ACS Applied Materials & Interfaces
·
2020
·
IF 8.758
Jia Yang,Xianqiang Yu,Xiangbin Sun,Qiong Kang,Lin Zhu,Gang Qin,Aiguo Zhou,Gengzhi Sun,Qiang Chen
It is a challenge to realize high strength, toughness, and energy storage, as well as excellent capacitive self-recovery, fatigue-resistant, and self-healing performances simultaneously in a single all-in-one supercapacitor aiming for wearable electronics. Herein, based on the self-crosslinking and molecular template, a supramolecular poly(vinyl alcohol)/poly (N-hydroxyethyl acrylamide) (PVA/PHEA) hydrogel electrolyte (HGE) decorated by polyaniline (PANI) was prepared by in situ rapid polymerization of high-concentration aniline on the PVA/PHEA gel containing H2SO4. The multiple hydrogen bonds, rapid polymerization, and decoration endowed PANI-decorated PVA/PHEA HGE-based all-in-one flexible supercapacitor with the integrated high performances, which include high specific capacitance, good cycling stability, high strength, excellent toughness, rapid self-recovery, excellent fatigue-resistant, and self-healing capabilities, as well as high capacitance retention during or after the large deformations or after the self-healing. Thus, the current work presents a novel and promising strategy to design the integrated high-performance supercapacitors aiming for wearable electronics.
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高影响因子
NEW JOURNAL OF CHEMISTRY
·
2020
·Vol. 44
·期 8
·3504-3513
·
IF 3.288
Qingqing Zhou,Jiayi Chen,Tianchi Zhou,Jianzhong Shao
A flame-retardant conductive cotton fabric switch was successfully prepared by the in situ polymerization of polyaniline doped with novel phytic acid (PA) by impregnation in an ice water bath for 24 h. The surface morphology, chemical composition, and thermal properties of the fabric before and after the in situ polymerization of polyaniline with PA were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), thermogravimetric analysis (TG), and TG-FTIR. The experimental results demonstrated that the limiting oxygen index (LOI) of the original fabric increased to 32% and the sheet resistance (Rs) decreased to 1.13 kΩ □−1. Under the PA de-doped state, the fabric had no flame-retardant and conductivity properties. Nevertheless, the excellent flame-retardant and conductivity properties of the fabric were obtained once more after re-doping with PA, which indicated that the flame-retardant and conductive textile switch was prepared successfully. Remarkably, the variation in the P content by XPS and the characteristic absorption peak of PA by FTIR made the doping behavior of PA on the surface of different fabrics clear. During the pyrolysis of the original and finished fabric, the maximum decomposition temperature (Tmax) and the maximum emission (Te) of light gas decreased from 380 °C to 290 °C, and the carbon residue content increased from 12.6% to 39.2% at 700 °C, which indicated that the in situ polymerization of aniline doped with PA resulted in the superior flame-retardant property of the fabric. This work provides a green method and basis for the preparation of multi-functional textiles, thus improving the added value of textiles.
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高影响因子
MACROMOLECULAR MATERIALS AND ENGINEERING
·
2020
·Vol. 305
·期 3
·1900737
·
IF 3.853
Lizhang Chen,Weiying Zhang,Yuefeng Dong,Qiuyue Chen,Wanjun Ouyang,Xiao Li,Xiaoguang Ying,Jianying Huang
With the development of alternatives to traditional fossil energy and the rise of wearable technology, flexible energy storage devices have attracted great attention. In this paper, a polyaniline/poly(acrylamide-sodium acrylate copolymer) hydrogel (PASH) with high flexibility and excellent electrochemical properties for flexible electrodes is fabricated by freeze-thaw-shrink treatment of a highly water-absorptive hydrogel, together with in-situ polymerization of aniline at a low aniline concentration (0.1 mol L −1 ). The PASH exhibits a conductivity of 4.05 S m −1 and an elongation at break of 1245%. The freeze-thaw-shrink treatment greatly improves the electrochemical performance and stability of the conductive PASH. The area specific capacitance of PASH reaches 849 mF cm −2 and the capacitance maintains 89% after 1000 galvanostatic charge–discharge cycles. All the raw materials are conventional industrialized materials and no additional templating agent is needed during the entire synthesis process. This study provides a cost-efficient approach for the fabrication of conductive polymer hydrogels, which has a broad application prospect in flexible energy storage electronic devices.
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高影响因子
危险品化学品经营许可证（带存储）