CELLULOSE
·
2024
·Vol. 31
·期 10
·6141-6153
·
IF 4.9
Song Jun,Wang Linfeng,Shan Jicheng,Li Chuanmeng,Wang Mengdie
Cellulose liquid crystal solutions have been extensively studied, and the methylene length of mesogenic units has a significant influence on the properties of cellulose liquid crystal solutions. In this study, 4-(ω-(methylimidazole)alkyloxy)-4’-(cyano)-biphenyl (CBP-n) with 4–7 methylene lengths were synthesized as mesogenic units to prepare cellulose side chain liquid crystal in 1-Allyl-3-methylimidazolium chloride (AMIMCl). And their liquid crystal properties were studied by differential scanning calorimetry (DSC), in-situ infrared spectrometer (IR), torque rheometer, and polarizing microscope (POM). The results showed that CBP-n with 4–7 methylene lengths were thermotropic liquid crystal, and the cellulose/CBP-n/AMIMCl solutions were lyotropic liquid crystal when the concentration of cellulose is 6wt% and the concentration of CBP-n with methylene length 4 and 6 is 3wt%. In-situ IR proved that the liquid crystal formation of cellulose/CBP-n/AMIMCl solution was caused by the hydrogen bonding formed between cellulose and CBP-n. And the solutions have a fewer entanglement number and lower viscosity than those of methylene length 5 and 7, indicating that the hydrogen bonding interaction between CBP-n with even methylene length and cellulose molecule is stronger than that of odd methylene length. This study provides a new approach to produce cellulose fibers using cellulose/CBP-n/AMIMCl as a new renewable resource.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2013
·Vol. 130
·期 2
·1058-1063
·
IF 1.395
Xiulan Zhao,Qin Zhang,Lixin Xue,Qianru Shi,Kang Tao
Poly(ether ether ketone) with pendent sulfonimide groups (B-SPEEK) was prepared from poly(ether ether ketone), sulfuric acid, thionyl chloride, para -toluene sulfonate, and pyridine. The prepared B-SPEEK was characterized by Fourier transform infrared spectroscopy, 1 H-NMR, and thermogravimetric analysis. The swelling of the gels was examined in N,N -dimethylacetamide (DMAC), N,N -dimethylformamide (DMF), 1-methyl-2-pyrrolidinone (NMP), dimethyl sulfoxide (DMSO), and a DMSO/water mixture. The gel showed extremely high swelling in DMSO, DMF, DMAC, and NMP. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1058-1063, 2013
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
SOLAR ENERGY MATERIALS AND SOLAR CELLS
·
2020
·
IF 6.984
Peiyu Tan,Feifei Lu,Yuge Han
A new type of device with adjustable reflective capabilities in the mid-IR is elaborated from the combination of Poly (3,4-ethylenedioxythiophene)/Poly (styrenesulfonate) (PEDOT/PSS), gold-coated non-porous polyimide substrate and gel electrolyte. Prior to device characterization, the influence of polymer thickness and gold substrate types on reflectance modulation of PEDOT-Au films is scrutinized to obtain the film with optimum quality. A combination of SEM images and reflectance curves confirms that adopting thin PEDOT/PSS on the non-porous substrate can achieve large amplitude reflectance regulation. Further, a mechanical perforating method is developed to address the issue that ions cannot transport between the polymer film and the counter electrode when this PEDOT/non-porous film assembled into device. An in-depth study shows that by varying the punching side, porosity and aperture, a device with front holes of porosity 12.77% affords the highest reflectance contrast of 0.566 over the wavelength range of 3-5 μm, meanwhile exhibits effective temperature changes of approximately 16 °C. These results inspire interesting perspectives regarding the fabrication of PEDOT-based devices with controllable IR electroreflective performance.
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
SEMICONDUCTOR SCIENCE AND TECHNOLOGY
·
2021
·Vol. 36
·期 12
·125008
·
IF 2.352
Junshuai Gong,Zhiliang Wang,Huiwen Qu,Dingyong Cang
A coplanar waveguide flexible filter based on the polyimide substrate was fabricated by self-metallization technology. The measured results indicate that the central frequency of the proposed filter is 2.5 GHz, the minimum insertion loss is −0.71 dB and the return loss is better than −20 dB. To test the conformal characteristics of the filter, bending and folding tests were performed. The test results show that the measured and simulated results are basically the same when the filter is bent and folded. The flexible filter fabricated by self-metallization technology is expected to be one of the components of future flexible wireless communication systems.
研究领域:
电子工程
·
通信技术
✓ 已验证
DOI
高影响因子
MOLECULES
·
2024
·Vol. 29
·期 23
·5763
·
IF 4.2
Jianing Sun,Xixi Lian,Lianzhi Wang,Zhengchao Duan
A covalent organic framework (COF) based on imine was synthesized using 2,5-dihexoxyterephthalaldehyde (DHT) and 1,3,5-tris(4-aminophenyl) benzene (TAPB) as starting materials. The TAPB-DHT-COF exhibited satisfactory chemical stability, making it a promising adsorbing material for stir bar sorptive extraction (SBSE) of four estrogens, including estrone (E1), β-estradiol (E2), hexestrol (HES), and mestranol (MeEE2), in ambient water samples. The extracted analytes were subsequently analyzed using a high-performance liquid chromatography-diode array detector (HPLC-DAD). A series of parameters affecting the SBSE process, such as solution pH, ionic strength, extraction time, and desorption solvent, were investigated by the controlled variable method. Under optimal conditions, the limit of detection (LODs) for the four targeted estrogens ranged from 0.06 to 0.15 µg/L, with a linear range from 0.2 to 100 µg/L. The observed enrichment factor (EF) ranged from 39 to 49, while the theoretical EF was estimated to be 50-fold. This methodology can be applied to the identification of estrogens in three environmental water samples.
研究领域:
分析化学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Yucong Liao,Shengqiu Zhao,Guoliang Liu,Hao Li,Jiaqi Shuai,Letian Wang,Bingxuan Liu,Haolin Tang
Proton exchange membrane fuel cells (PEMFCs) face a significant challenge when operating in high-temperature and low-humidity environments, the hydrocarbon-based polymers that are sulfonated or phosphonated can’t meet the demand for achieving high performance. Modifying perfluorosulfonyl fluoride (PFSF) through meticulous design of side-chain chemical structures and introducing functionalized sulfonimide and phosphonic acid groups. Membranes derived from a perfluorocarbon backbone and polyacid side chain structures exhibit distinct microphase separation. The sulfonimide group exhibits hyper-acidic properties, whereas the phosphonic acid group functions as proton acceptor and donor. These two groups work synergistically to establish a distinct proton transport channel. The robust adsorption between acidic functional groups and water molecules enhances the diffusion of water molecules, resulting in an increase in proton conductivity. Moreover, Density Functional Theory (DFT) calculations reveal that the phosphonic acid group of the side chain has difficulty forming anhydrides. The prepared perfluorosulfonimide-phosphonic acid (PFSNPA) proton exchange membrane demonstrates an impressive conductivity of 263 mS·cm −1 at 120 °C. In H 2 /Air fuel cell tests, PFSNPA achieves an outstanding output power of 1076.1 mW·cm −2 at 120 °C and 40 % RH. This study introduces a new approach for designing and fabricating proton exchange membrane materials for high-temperature fuel cells.
研究领域:
材料科学
·
能源工程
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED ENGINEERING MATERIALS
·
2021
·Vol. 23
·期 12
·2100623
·
IF 3.862
Yu Yao,Wei Guo,Xingwen Zhou,Peng Peng
The growing demand for highly efficient heat management in flexible electronics requires fabrication of highly conductive flexible films. Herein, Cu–C film on a polyimide (PI) substrate is fabricated to form a layered Cu–C/PI composite conductive film using direct laser writing. Its oxidation resistance is significantly improved compared with the written Cu film due to the presence of a graphite shell on Cu particles in the Cu–C film. Furthermore, the Cu–C/PI composite film shows better thermal properties than Cu/PI. This work provides a one-step method for rapidly fabricating Cu/PI and Cu–C/PI composites with good thermal stability and conductivity.
研究领域:
材料科学
·
柔性电子学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Jing Jin,Renyuan Wang,Ke Yu,Yueheng Tao,Peipei Zhang,Lei Ke,Jun Yang,Minjie Shi
The design of innovative faradaic electrode materials is crucial for improving the removal efficiency of contaminants in hybrid capacitive deionization (HCDI) systems. Organic compounds are a promising choice for faraday electrodes due to the sustainable production and tunable molecular structure. However, their high solubility in aqueous media and limited availability of redox-active sites for deionization greatly constrain the HCDI applications. Herein, we intentionally construct a conjugated polymer (IMP) with abundant imine groups, in which the strategic integration of N-heteroaromatic rings within the π-conjugated framework effectively prevents the disintegration of redox-active entities, while honing the energy bandgap and electronic characteristics. The copious redox-active C N sites within the imine groups along the polymeric chain markedly improve its capacity for the high-efficiency (de)intercalation of NH 4 + ions. As an electrode material, the IMP polymer exhibits a significant NH 4 + -storage capacitance of 257.1 F g −1 at 2 A g −1 and maintains an ultra-cycle stability of 96.1 % after 10,000 cycles (4 A g −1 ), as evidenced by the in-situ spectral analysis of electrolyte. For real applications, a HCDI configuration has been constructed with a high specific NH 4 + adsorption capacity of 119.0 mg g −1 and a fast removal rate of 27.0 mg g −1 min −1 with stable regeneration performance.
研究领域:
材料科学
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环境工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2021
·Vol. 13
·期 8
·1329
·
IF 4.329
Maijun Li,Zhibo Zheng,Zhiguang Zhang,Nanwen Li,Siwei Liu,Zhenguo Chi,Jiarui Xu,Yi Zhang
To improve the interfacial compatibility of mixed matrix membranes (MMMs) for gas separation, microporous polyimide particle (AP) was designed, synthesized, and introduced into intrinsic microporous polyimide matrix (6FDA-Durene) to form “all polyimide” MMMs. The AP fillers showed the feature of thermal stability, similar density with polyimide matrix, high porosity, high fractional free volume, large microporous dimension, and interpenetrating network architecture. As expected, the excellent interfacial compatibility between 6FDA-Durene and AP without obvious agglomeration even at a high AP loading of 10 wt.% was observed. As a result, the CO2permeability coefficient of MMM with AP loading as low as 5 wt.% reaches up to 1291.13 Barrer, which is 2.58 times that of the pristine 6FDA-Durene membrane without the significant sacrificing of ideal selectivity of CO2/CH4. The improvement of permeability properties is much better than that of the previously reported MMMs, where high filler content is required to achieve a high permeability increase but usually leads to significant agglomeration or phase separation of fillers. It is believed that the excellent interfacial compatibility between the PI fillers and the PI matrix induce the effective utilization of porosity and free volume of AP fillers during gas transport. Thus, a higher diffusion coefficient of MMMs has been observed than that of the pristine PI membrane. Furthermore, the rigid polyimide fillers also result in the excellent anti-plasticization ability for CO2. The MMMs with a 10 wt.% AP loading shows a CO2plasticization pressure of 300 psi.Keywords:mixed-matrix membranes;compatibility;microporous polyimide particle;polyimide matrix;permeability
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Polymers
·
2019
·Vol. 11
·期 12
·2068
·
IF 3.164
Huiwen Qu,Zhiliang Wang,Dingyong Cang
Polymer, especially polyimide (PI), is the best suitable substrate material for the design of flexible electronics. The compact silver can be reduced on the surface of PI films by surface modification and in situ self-metallization technique. The formed silver layers have good electrical and mechanical flexibility. A flexible bandpass filter on a PI flexible substrate by surface modification and in situ self-metallization technique at room temperature are presented in this work. Measured results show that the proposed flexible bandpass filter could achieve a fractional bandwidth of 80.8% with an insertion loss (IL) of less than 0.6 dB. The performance of the designed filter is almost constant under different bending, folding, and rolling conditions. The formed silver layers also present good adhesion with PI substrates. This technology provides an alternative approach for manufacturing flexible filters without high-temperature thermal annealing, costly equipment, and vacuum conditions.Keywords:flexible electronics;polyimide substrate;bandpass filter;surface modification;in situ self-metallization
研究领域:
电子工程
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
AICHE JOURNAL
·
2019
·Vol. 65
·期 8
·e16620
·
IF 3.463
Xiaoxu Zhao,Hao Zhang,Sheng Xu,Yan Wang
In this study, a novel covalent-assisted seeding method is developed to fabricate well-intergrown ZIF-8 membrane on polyimide (PI) substrate with imidazole-2-carboxaldehyde (ICA) as the covalent agent between ZIF-8 layer and PI substrate. Compared to ethylenediamine-crosslinked PI membrane and ZIF-8/PI membrane synthesized without covalent-assisted seeding method, ZIF-8/PI membrane synthesized with ICA covalent-assisted seeding method shows improved pervaporation performance for isopropanol dehydration. Subsequent surface coating with polydimethylsiloxane or polydopamine is applied to mitigate the grain boundary of ZIF-8/PI membrane, which results in a further performance enhancement. The morphologies and physicochemical properties of the resultant membranes are characterized by scanning electron microscope, attenuated total reflectance-Fourier transform infrared, X-ray diffraction, and water contact angle. The effect of operation temperature on the separation performance is also carried out. This work demonstrates the novel covalent-assisted seeding method for the preparation of ZIF-8 membrane with high-performance, which may hold a great potential for various ZIF membranes separation applications.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2022
·
IF 10.53
Baoyin Li,Xinda You,Hong Wu,Runlai Li,Ke Xiao,Yanxiong Ren,Hongjian Wang,Shuqing Song,Yuhan Wang,Yunchuan Pu,Xiaochun Huang,Zhongyi Jiang
Fabricating metal-organic framework (MOF) membranes on processable and flexible polymeric substrates is of great significance for potential practical application, but remains technically challenging due to the lack of nucleation sites on polymeric substrates. Here, we report an efficient and facile method to render abundant and uniform nucleation sites on the substrate surface by pre-anchoring metal ions through coordination-driven self-assembly of metal-organophosphate. The coordination between the multidentate phytic acid (PA) and the metal ions enables the functionalization of polymeric substrates with a metal-phytic acid layer, which anchors metal ions to promote the subsequent generation of thin and defect-free MOF layers thereon. As an illustration, the ZIF-8 membrane was synthesized on Zn 2+ -PA functionalized polyacrylonitrile substrate and optimized by regulating the pre-anchored Zn 2+ content. The obtained ZIF-8 membrane exhibited a superior separation performance for C 3 H 6 /C 3 H 8 mixture, harvesting selectivity up to 150 with C 3 H 6 permeance of 70 GPU. Besides, the polycrystalline ZIF-8 membrane also displays excellent bending and pressure resistance due to the strong combination between the MOF layer and the polymeric substrates from the fortified and robust bridging coordination effect of the metal-organophosphate layer. Our strategy can be extended to diverse MOFs and polymeric substrates, paving a facile and generic way to fabricate MOF membranes.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）