CHINESE JOURNAL OF POLYMER SCIENCE
·
2021
·Vol. 39
·期 9
·1211-1216
·
IF 3.603
Xiang Ming-Yue,Lyu Dong,Liu Ling-Zhi,Men Yong-Feng
Crystallinity of bottlebrush polymers due to side chain crystallization has been considered to be related to the length of the side chains only under the assumption of complete participation of crystallization by all side chains. Recent experimental results revealed that in poly( n -alkyl methacrylate)s a fraction of side chains could not crystallize due to constraints imposed by the trapped main chain entanglements and required expansion of main chain-main chain distance. This result renders the original simplified consideration of the origin of crystallinity in bottlebrush polymers questionable. In this work, we introduce a new parameter f c , the fraction of crystallizable side chains, to better describe the crystallinity of bottlebrush polymers. A linear relationship between the melting enthalpy and the number of alkyl groups in side chains for bottlebrush polymers reported repeatedly indicates that f c remains essentially unchanged when bottlebrush polymers had the same main chain structure and grafting degree but different side chain lengths. The slope of the above-mentioned linear relationship is thus \(\Delta H_{\text{CH}_2}\times f_{c}\) , where \(\Delta H_{\text{CH}_2}\) stands for the melting enthalpy of one mole alkyl group packed into the crystal. With a known value of f c , it is possible to estimate the value of \(\Delta H_{\text{CH}_2}\) . In case of poly( n -alkyl methacrylate)s, we estimated \(\Delta H_{\text{CH}_2}\) of hexagonal crystal being at most 5.74 kJ/mol with the knowledge of possibly smallest f c of 0.67 obtained from small angle X-ray scattering data. Therefore, the crystallinity of bottlebrush polymer would be calculated based on the equation \(X_{\rm{c}}=f_{\rm{c}}\times\frac{N_{\rm{c}}}{N}\) with N and N c being the number of alkyl groups in a side chain and those packed in the crystalline structure, respectively. Both chemical structure and grafting degree of bottlebrush polymers affect f c .
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Longkai Pan,Li Yao,Hui Mei,Hongxia Liu,Zhipeng Jin,Shixiang Zhou,Minggang Zhang,Gangqiang Zhu,Laifei Cheng,Litong Zhang
In this study, a novel 3D Bi 2 S 3 /P-ZnO S-scheme gyroid metamaterial was prepared by 3D printing and the hydrothermal method. The unique gyroid macrostructure and nanoarray microstructure offer a large volume of active sites for the photothermal catalytic reaction, thus improving the overall utilization rate of light. ZnO obtained by sintering the precursor produces oxygen vacancies, primarily due to P doping. This enables it to have a photothermal effect. After loading Bi 2 S 3 , the photothermal effect of P-ZnO and Bi 2 S 3 is coupled, further increasing the surface temperature of composite structure and speeding up the reaction rate. P-ZnO and Bi 2 S 3 formed a S-scheme heterojunction, promoting the separation and transfer of photogenerated carriers. Under simulated sunlight, the CO and CH 4 yield of Bi 2 S 3 /P-ZnO S-scheme gyroid metamaterials are 8.87 and 1.49 μmol h −1 . These are 3.45 times and 4.65 times of P-ZnO gyroid structure, respectively. Through SEM, TEM, XPS, ESR and in-situ FTIR characterizations, the transfer paths of photogenerated carriers between heterojunctions were revealed, and the reaction paths of photothermal catalytic CO 2 reduction were explored. The co-design of 3D structure and material allows for a novel concept for further improving photothermal catalytic performance.
✓ 已验证
DOI
高影响因子
Materials Today Chemistry
·
2024
·
IF 6.7
Xiaoyu Zhou,Chuanliang Wu,Zelin Zhao,Yusheng Wang,Yuanyuan Yang,Jingxing Guo,Jia Wang,Xiaolong He,Yinyu Xiang,Ning Han,Junsheng Li
Despite the bright future of aluminum-sulfur (Al–S) batteries due to the ultrahigh energy-to-price ratios, the development of this new energy storage system is plagued by the shutting of polysulfides and sluggish kinetics during redox conversions. Herein, ferrocene as efficient polysulfide mediators and electrocatalysts is covalently grafted onto glass fiber (GF) membranes, which serves as separators in Al–S batteries. Attributed to the strong chemisorption and catalytic effect of metallocene toward polysulfide conversions, Al–S cells assembled with the grafted separators deliver an ultrahigh initial capacity of 1347.9 mAh g −1 (at 200 mA g −1 ) and desirable rate performance (328.1 mAh g −1 at 500 mA g −1 ). As validated by theoretical calculations, effective polysulfide binding is achieved through beneficial cation-π interactions between Al 3+ in polysulfides and the negatively charged cyclopentadienyl ligands in ferrocene, providing novel insights into the exploration of metal-sulfur chemistries for stable energy storage.
✓ 已验证
DOI
高影响因子
SOLAR ENERGY
·
2019
·
IF 4.674
Yefeng Wang,Jing Hui Zeng,Guangtao Zhao
Developing cost-effective solid-state electrolyte is a urgent issue and a common request for (photo) electrochemical cells. In this work, a series of organic ionic conductors based on the S -substituted benzothiophenium salts have been synthesized via a simple and low-cost method. Research on the thermal behavior, optical absorption and ionic conductivity shows that S -methylbenzothiophenium tetrafluoroborate ([MBT]BF 4 ) among them have the good thermal stability, high ionic conductivity and no absorption in the visible region. And the solid-state electrolyte using [MBT]BF 4 as the matrix exhibits the good interfacial compatibility with photoanode. Applying this solid-state electrolyte into the quantum-dot sensitized solar cell (QDSSCs), the device achieves an open circuit voltage of 0.71 V, a short circuit current density of 20.73 mW cm −2 , and a power conversion efficiency of 5.49% which is higher than those previously reported for the solid-state QDSSCs.
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2022
·
IF 7.139
Jianhua Yu,Xiancai Pang,Qunchao Yin,Di Chen,Hongzhou Dong,Qian Zhang,Jing Sui,Lina Sui,Lifeng Dong
Constructing self-supporting porous electrode material with abundant electrochemical active sites can effectively improve the energy storage capacity of supercapacitors . Herein, a novel electrode material (NCS@Co-ZIF/NF) is developed by depositing zeolitic imidazolate frameworks (Co-ZIF) on nickel foams (NF), which is adopted as a precursor (Co-ZIF/NF) to electrodeposit nickel-cobalt sulfides (NCS). The nanosheet arrays with cross-porous structures provide NCS@Co-ZIF/NF with excellent electrochemical characteristics, including a high specific capacity of 144.4 mAh g −1 at the current density of 1 mA cm −2 , 60.5% capacity retention at 50 mA cm −2 , and superb long-term cycle stability. Furthermore, NCS@Co-ZIF/NF//AC hybrid supercapacitor is fabricated by using NCS@Co-ZIF/NF as positive electrodes and activated carbon (AC) as negative electrodes , which exhibits a high energy density of 33.9 Wh kg −1 at a power density of 145 W kg −1 .
✓ 已验证
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2017
·
IF 5.951
Shusen You,Songqi Ma,Jinyue Dai,Zhen Jia,Xiaoqing Liu,Jin Zhu
Hexahydro-s-triazine (HT) derivatives are acid-sensitive compounds. 4,4′,4″-(1,3,5-Hexahydro-s-triazine-1,3,5-triyl) tris(N-(2-aminoethyl) benzamide) (HT-A) bearing three amino groups was synthesized as a curing agent to prepare the acid-degradable epoxy resin. The chemical structures of HT-A and its precursor were confirmed by 1H NMR and 13C NMR. The synthesized HT-A, as well as the commercialized 4,4′-diaminodiphenylmethane (DDM) (for use as the control) were used to cure diglycidyl ether of bisphenol A (DGEBA), respectively. The property examinations performed by dynamic mechanical analysis (DMA), differential scanning calorimeter (DSC), thermogravimetric analysis (TGA), and tensile test demonstrated that the HT-A-cured epoxy presented high thermal and mechanical properties which were comparable with those of the DDM cured one. Meanwhile, degradation investigation indicated that the HT-A-cured epoxy could be controllably degraded with strong acid stimuli. Thus, HT-A has a great potential to produce recyclable thermosets with satisfactory properties.
✓ 已验证
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2021
·
IF 8.198
Hongbing Song,Yongjie Wang,Yule Liu,Lei Chen,Bingxiao Feng,Xin Jin,Yu Zhou,Tingting Huang,Meng Xiao,Fangmin Huang,Hengjun Gai
Three ionic liquid (IL) monomers consisting of one, two, and four benzene rings were designed with 2-phenylimidazole and polymerized with α,α′-dichloro-p-xylene (DCX) and formaldehyde dimethyl acetal (FDA) to form a series of novel poly(ionic liquid)s (PILs). In this process, the designed ILs were employed as active ionic sites, and DCX and FDA were selected as cross-linkers. Self-condensation of the cross-linker provided a large specific surface area for the hypercross-linked organic framework, while co-condensation between the cross-linker and IL introduced active sites to the framework. The obtained porous hypercross-linked PILs not only promoted CO2 capture and the selective absorption of CO2/N2 but also showed good activity for the cycloaddition of epoxide with CO2. HP-[BZPhIm]Cl-DCX-1 with a large surface area (763 m2·g–1) showed a CO2 uptake capacity of 1.47 mmol·g–1 and offered a 98.9% yield of the CO2 cycloaddition product with epichlorohydrin at 80 °C for 24 h under 0.1 MPa CO2 pressure. The designed PILs provide an important reaction for CO2 utilization.
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Qiubo Lan,Jinxu Ma,Siyuan Li,Kepi Chen,Cuiwei Li,Linan An
Since high-entropy oxide has a huge compositional space, it is urgent to develop efficient methods to quickly find the compositions that can form single-phase materials. In this paper, taking (Ce, Zr, Hf, Yb, Nb)O 2 system as an example, we carried out the design and preparation of high-entropy fluorite oxides (HEFOs) by constructing a R ‾ -S diagram. Three single-phase HEFOs have been successfully design and synthesized. The impedance measurement showed that the three materials are electronic conductors, which exhibited relatively low thermal conductivities ranging between 1.6 W/m·K ∼1.9 W/m·K. The current study suggests that R ‾ -S diagram is a useful tool for quickly selecting compositions that can form single-phase high-entropy oxides.
✓ 已验证
DOI
高影响因子
RSC Advances
·
2023
·Vol. 13
·期 49
·34524-34533
·
IF 3.9
Suo Zhao,Qiao Wang,Jin Liu,Xianglong Hao,Xiao Liu,Wenfei Shen,Zhonglin Du,Yao Wang,Mikhail Artemyev,Jianguo Tang
In this study, ZnS capped Cu–In–S (ZCIS) quantum dots doped with Mn ions are synthesized by a thermal injection method, with luminescence covering almost the entire visible area. The large Stokes shift effectively inhibits the self-absorption effect under luminescence, and the quantum yield of ZCIS quantum dots increased from 38% to 50% after ZnS capping and further to 69% after doping with Mn. First, red-, yellow-, and blue-emitting quantum dots were synthesized and then, polychromatic ensembles were obtained by mixing the trichromatic quantum dots in a different ratio. Using the home-built inkjet printer, multilayered and multicolor mixed patterns were obtained for information pattern storage and multilayer pattern recognition and reading.
✓ 已验证
DOI
高影响因子
RSC Advances
·
2018
·Vol. 8
·期 49
·27686-27694
·
IF 2.936
Xue Yu,Shuying Cheng,Qiong Yan,Jinling Yu,Wen Qiu,Zhengji Zhou,Qiao Zheng,Sixin Wu
Cation substitution plays a crucial role in improving the efficiency of Cu2ZnSn(S,Se)4 (CZTSSe) solar cells. In this work, we report a significant efficiency enhancement of flexible CZTSSe solar cells on Mo foils by partial substitution of Cu+ with Ag+. It is found that the band gap (Eg) of (Cu1−xAgx)2ZnSn(S,Se)4 (CAZTSSe) thin films can be adjusted by doping with Ag with x from 0 to 6%, and the minimum Eg is achieved with x = 5%. We also found that Ag doping can obviously increase the average grain size of the CAZTSSe absorber from 0.4 to 1.1 μm. Additionally, the depletion width (Wd) at the heterojunction interface of CAZTSSe/CdS is found to be improved. As a result, the open-circuit voltage deficit (Voc,def) is gradually decreased, and the band tailing is suppressed. Benefiting from the enhanced open-circuit voltage (Voc), the power conversion efficiency (PCE) is successfully enhanced from 4.34% (x = 0) to 6.24% (x = 4%), and the Voc,def decreases from 915 to 848 mV.
✓ 已验证
DOI
高影响因子
ACS Applied Energy Materials
·
2018
·
IF 0
Libin Wang,Huiling Yang,Ting Shu,Yue Xin,Xue Chen,Yuyu Li,Heng Li,Xianluo Hu
Li-ion capacitors, comprising a battery anode and a supercapacitor cathode, have been expected to bridge the gap between batteries and supercapacitors. However, the kinetics mismatch between the anodic sluggish insertion and the cathodic capacitive process has impeded the energy-storage potential of devices. Developing pseudocapacitive anode materials is urgently needed in that pseudocapacitance can deliver energy in the same time scale as electrostatic adsorption and offer a comparable level of energy storage to that of battery-type materials. Here we demonstrate an inside and outside synergistic nanoengineering strategy to synthesize nanoporous carbon-modified S-TiO2 hybrid nanosheets, through which both the carbon layer and sulfur doping can be simultaneously generated in situ. Benefiting from the in situ S doping, the electronic and ionic conductivity of anatase TiO2 nanoparticles is enhanced. The carbon-modified S-TiO2 with dominant pseudocapacitance realizes an unprecedentedly high capacity of 550 mAh g–1 at 0.3 C and excellent rate capability, outperforming that of the ever-reported TiO2-based materials. Furthermore, a hybrid Li-ion capacitor based on the as-obtained carbon-modified S-TiO2 electrode has been assembled, delivering a high energy density of 92.7 Wh kg–1 and power density of 26 kW kg–1 with a stable cycling life (85.8% after 10 000 cycles). Our work offers a new avenue for achieving electrode materials with extrinsic pseudocapacitance that is kinetically comparable to capacitive materials.
✓ 已验证
DOI
ACS Applied Materials & Interfaces
·
2016
·
IF 7.145
Chao-Ying Fan,Si-Yu Liu,Huan-Huan Li,Hai-Feng Wang,Han-Chi Wang,Xing-Long Wu,Hai-Zhu Sun,Jing-Ping Zhang
The synergistic design of cathode region was conducted to minimize the shuttle effect of polysulfides and decrease the loading of inactive components in order to acquire high-energy-density lithium–sulfur (Li–S) batteries. The well-designed cathode region presented two special characteristics: one was the intertwined nanofibers interlayer based on ultrafine TiO2 nanocrystal uniformly embedded within N-doping porous carbon; the other was the lightweight and three-dimensional current collector of fibrous cellulose paper coated by reduced graphene oxide. In consequence, the decent reversible capacity of 874.8 mA h g–1 was acquired at 0.1 C with a capacity retention of 91.83% after 100 cycles. Besides, the satisfactory capacity of 670 mA h g–1 was delivered after 300 cycles at 1 C with the small decay rate of only 0.08%. Because of higher capacity and lower loading of inactive component in cathode region, the energy density of cell increased more than five times compared with unmodified cell. Moreover, to further enhance the energy density, the high-sulfur-loading electrode was fabricated. A good areal capacity of 4.27 mA h cm–2 was retained for the cell with the active material of 4 mg cm–2 and the cycle stability was also well-maintained. In addition, due to the flexibility of interlayer and current collector, Li–S full cell (in pouch cell format) was easily curved. Therefore, the synergistic design for cathode region, which combines the flexible and mass-produced interlayer and current collector together, provides an effective access to Li–S batteries with high energy density and flexibility for practical application.
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）