ACS Applied Materials & Interfaces
·
2021
·
IF 9.229
Ying Shen,Dawei Li,Lanlan Wang,Yuqi Zhou,Feng Liu,Huiping Wu,Bingyao Deng,Qingsheng Liu
Nanofiber membranes via electrospinning with layered structures are frequently used for oil/water separation, thanks to their unique properties. However, challenges that involve nanofibrous membranes still remain, such as high energy consumption and unfavorable transport properties because of the densely compact structure. In this study, superelastic and robust nanofiber-based aerogels (NFAs) with a three-dimensional (3D) structure as well as tunable porosity were prepared using polyimide (PI) nanofibers via a freeze-drying process followed by the solvent–vapor treatment. The porous NFAs were further modified using trichloromethylsilane (TCMS) to generate silicone nanofilaments (SiNFs) on the surface of the PI nanofibers, which could enhance the hydrophobicity (water contact angle 151.7°) of the NFAs. The corresponding superhydrophobic NFAs exhibited ultralow density (<10.0 mg m–3), high porosity (>99.0%), and rapid recovery under 80% compression strain. SiNFs-coated NFAs (SiNFs/NFAs) could also collect a wide range of oily solvents with high absorption capacities up to 159 times to their own weight. Moreover, surfactant-stabilized water-in-oil emulsions could also be efficiently separated (up to 100%) under the driving force of gravity, making it a promising energy-efficient technology. Additionally, SiNFs/NFAs maintained high separation efficiency throughout five separation–recovery cycles, indicating the potential of SiNFs/NFAs in the field of oil/water separation, sewage treatment, as well as oily fume purification.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2020
·
IF 6.182
Dongliang Zhang,Yu Lin,Wei Wang,Yuxuan Li,Guozhang Wu
We report a novel procedure to fabricate vacuum dried high-mechanical-strength polyimide (PI) aerogels cross-linked with dopamine-functionalized carbon nanotubes (mCNTs). Poly(amid acid) chains are in situ grafted onto the surface of mCNTs via “grafting from” method, thus providing the composite aerogels with superior mechanical properties due to covalently chemical cross-link networks and linear reinforcement. The addition of only 1.0 wt% of mCNT endows the composite aerogel with the specific modulus of 715.5 J/g, which is much higher than that of chemical agent cross-linked aerogels. The obtained composite aerogels also show high thermal stability and enhanced flame retardant performance, with only a slight increase in weight loss and shrinkage after firing test. Furthermore, mCNTs can serve as secondary reaction platform, thus superhydrophobic and oleophilic composite aerogels were fabricated by grafting octadecylamine onto the aerogel surface. The water contact angle is as high as 151°, and the maximum oil absorption capacity is 447%. Moreover, the composite aerogels exhibit stable hydrophobic and oleophilic properties after a long period of strong acid/base or high-temperature treatments, which is promising for practical oil-water separation applications under severe environments.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2020
·Vol. 137
·期 36
·49068
·
IF 2.52
Bing Liu,Dan Li,Jie Yao,Hao Sun
Branched polyethyleneimine (PEI) functionalized UiO-66 were synthesized and used as fillers to fabricated mixed-matrix membranes (MMMs) for CO 2 /CH 4 separation. The purpose of introducing amino-functional groups in the filler is to improve the interfacial compatibility of the filler with the polymer through the formation of hydrogen bonds with the carbonyl group of 6FDA-ODA. Additionally, the amino group can facilitate CO 2 transport through a reversible reaction, enhancing the CO 2 /CH 4 separation properties of MMM. The chemical structure and morphology of fillers and membranes were characterized by employing X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectrometer (FTIR), X-ray diffraction (XRD), thermogravimetric (TGA), Derivative thermogravimetry (DTG) and scanning electron microscope (SEM). Furthermore, the effects of filler loading and feed pressure on CO 2 permeability and CO 2 /CH 4 selectivity have been investigated. MMMs present higher gas separation performance than pure 6FDA-ODA due to the presence of amino groups and the improvement of interface morphology. In particular, the MMM with 15 wt% loading of UiO-66-PEI shows optimum CO 2 permeability of 28.23 Barrer and CO 2 /CH 4 selectivity of 56.49. Therefore, post-synthetic modification of UiO-66 particle with PEI is a promising alternative to improved membrane performance.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2020
·Vol. 55
·期 13
·5667-5679
·
IF 3.553
Wang Di,Yu Jiajun,Duan Gaigai,Liu Kunming,Hou Haoqing
Electrospun polyimide (PI) nanofiber nonwovens with excellent mechanical and thermal performance are highly required in many applications. The addition of phosphorus-containing compounds could be used as plasticizer to achieve this purpose. Herein, different amounts of trace diphenyl phosphate (DPhP) as plasticizer are added into the PI’s precursor for electrospinning. After imidization, phosphorous-containing electrospun PI nonwovens (PI-P X ) are produced. The results indicate that the addition of DPhP significantly enhanced the thermal and mechanical properties of PI-P X . PI-P0.6 (0.6 wt% DPhP) shows a T 5% of 510 °C in air and 561 °C in Ar, 29 °C and 40 °C higher than those of pure PI. PI-P0.6 also shows the highest tensile strength/modulus/toughness of 44 MPa/2.0 GPa/8.5 MPa, 208 MPa/9.7 GPa/40.7 MPa, and 123 MPa/3.3 GPa/25.1 MPa, respectively, when applying different thickness determinations. In addition, PI-P0.6 also exhibited much higher puncture strength than other Li-ion battery separators. Such PI-P X composite nonwovens would be good candidates for various applications, especially for Li-ion battery separators.
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
·
2020
·
IF 6.444
Ao Zhong,Jinhui Li,Yu Zhang,Fan Zhang,Tao Wang,Guoping Zhang,Rong Sun,Ching-Ping Wong
The mechanical brittleness and structure collapse of three-dimensional (3D) graphene composite construction is still an enormous issue in flexible performance of complex. In addition, low temperature and efficient process become increasingly significant and noticeable in field of semiconductor device to prevent from huge resource waste and energy consumption. Herein, we report a special method to prepare 3D graphene/polyimide (rGO/PI) aerogel with low temperature and rapid procedure. The aerogel is synthesized by introducing water-soluble polyamic acid ionic salt (PAS) and ice-templating directional solidification to establish unique oriented structure, and by energy-efficient microwave to realize low temperature and rapid imidization. The preparative rGO/PI nanocomposite aerogels hold excellent electrical conductivity , desirable flexibility, superior pressure-responsive properties, remarkable compression sensitivity and durability, so that adapt to multifarious deformations with huge potential for flexible wearable devices .
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Yujie Wang,Ying Cui,Ziyu Shao,Weiwei Gao,Wei Fan,Tianxi Liu,Hao Bai
Thermoregulating textiles (or protective clothing) are highly demanded for both human health and labor productivity especially in hot working environments. It is challenging to balance wearability and thermal insulating property as they usually demand for opposite porosity. Here, learning from the porous structure of polar bear hair, we report a polyimide aerogel fiber obtained by a freeze-spinning technique. A textile woven with such polyimide fiber is thermally insulating, strong and highly stretchable, fire-retardant (or self-extinguishing), and temperature-resistant. Additionally, it can be readily incorporated with other functions such as acid alkali resistance and thermoregulation by surface modification and infiltration of phase change material. All these properties indicate its potential in protective clothing in hot environments. With the versatility and scalability, our approach paves a new way for fabricating smart textiles with well-defined microstructure and multifunctionality by learning from nature.
✓ 已验证
产品关联
DOI
高影响因子
APPLIED ORGANOMETALLIC CHEMISTRY
·
2021
·Vol. 35
·期 12
·e6445
·
IF 4.105
Yijun Du,Faliang Gou,Danning Gao,Zhifeng Liu,Linjun Shao,Chenze Qi
In this study, palladium-encapsulated poly(amic acid) (Pd@PAA) nanofibers were prepared by electrospinning, followed by thermal imidization to synthesize palladium-encapsulated polyimide (Pd@PI) nanofibers. Scanning electron microscopy (SEM) images confirmed the preparation of uniform and smooth Pd@PAA and Pd@PI nanofibers. Thermogravimetric analysis (TGA) results reveal that the Pd@PI nanofibers possessed excellent thermal stability. The dispersion of palladium nanoparticles in the polyimide nanofibers was characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD). The catalysis results show that this Pd@PI fibrous catalyst was very efficient to catalyze the cross-coupling reactions of aromatic iodides with n -butyl acrylate (Heck reaction) or phenylboronic acid derivatives (Suzuki reaction) to afford the desired products in good to excellent yields. Moreover, the Pd@PI catalyst could be easily separated and recovered from the reaction mixture by simple filtration due to the regular fibrous structure and reused for 10 times for both Heck and Suzuki reactions without obvious loss of its initial catalytic activity. Thus, the Pd@PI nanofiber catalyst holds great potential in chemical industry in terms of its excellent catalytic activity and stability.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2019
·Vol. 137
·期 16
·48595
·
IF 2.188
Mengfan Liang,Yu Wang,Shuhong Sun,Wenlong Yang
In this article, the effects of coupling agent, silica particle size, and particle shape on the mechanical properties of polyimide (PI) were studied by molecular dynamics (MD) simulations, and the effect of SiO 2 surface treated with coupling agent on the mechanical properties of PI was investigated by experiment. At the same doping volume fraction (5%), the simulation results show that the surface interaction energy between the matrix and particle gradually increases with the radius of the embedded nanoparticles. Meanwhile, the interface interaction energy and mechanical properties of the sphere-type were significantly higher than the ones of other shaped nanoparticles. Moreover, the simulations were compared with the experimental results; atomic force microscopy and scanning electron microscopy images can verify that after being treated with coupling agent, interface interaction between nanosilica and PI enhances quite a little. The mechanical experimental results show that the tensile strength and elasticity modulus of pure PI, unbonded (UB) PI/SiO 2 , and bonded PI/SiO 2 films are 34.47 and 1.13, 36.46 and 1.32, and 66.20 MPa and 1.72 GPa, respectively. It is indicated that the coupling agent plays a crucial role in nanocomposites. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137 , 48595.
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES COMMUNICATIONS
·
2019
·
IF 0
Linlin Wang,Fan Liu,Weili Shao,Shizhong Cui,Yaomin Zhao,Yuman Zhou,Jianxin He
The battery separator is an important component of the battery which is related to the safety of the battery. However, there are many flaws of traditional lithium ion battery separator made by polyolefin , especially thermal stability and wettability . It was necessary, therefore, to invent a battery that heat resistance and electrolyte wettability. Here, we use the polyimide (PI) as a base material and graphene oxide (GO) as a reinforcing material, and get the nanofiber membrane through electrospinning technology, with the feature of three dimensional porous. Results show that as prepared PI nanofiber membrane possesses excellent thermal stability (no shrinkage even up to 200 °C), and admirable electrolyte absorption rate (2200%), which further significantly improves the ionic conductivity (2.04041 mS/cm). In addition, cells assembled with PI nanofiber membrane deliver outstanding cycling performance and C-rate discharge capability compared with 2400 separator in the same conditions. It is indicates that as-fabricated PI nanofiber separator has the potential of becoming a more mature technology offering better performance.
✓ 已验证
产品关联
DOI
ACS Applied Materials & Interfaces
·
2019
·
IF 8.456
Ning-Ning Wang,Hao Wang,Yu-Ying Wang,You-Hao Wei,Jing-Yu Si,Anthony Chun Yin Yuen,Jin-Song Xie,Bin Yu,San-E Zhu,Hong-Dian Lu,Wei Yang,Qing Nian Chan,Guan-Heng Yeoh
Polyimide (PI) aerogels have attracted great attention owing to their low density and excellent thermal stability. However, hydrophobic surface modification is required for PI aerogels to improve their ability in oil/water separation due to their amphiphilic characteristic. Two-dimensional MXenes (transition metal carbides/nitrides) can be utilized as nanofillers to enhance the properties of polymers because of their unique layered structure and versatile interface chemistry. Herein, the robust, lightweight, and hydrophobic PI/MXene three-dimensional architectures were fabricated via freeze-drying of polyamide acid/MXene suspensions and thermal imidization. Polyamide acid was synthesized using N-N-dimethylacetamide and 4,4′-oxydianiline. MXene (Ti3C2Tx) dispersion was obtained via the etching of Ti3AlC2 and ultrasonic exfoliation. Taking advantage of the strong interaction between PI chains and MXene nanosheets, the interconnected, highly porous, and hydrophobic PI/MXene aerogels with low density were fabricated, resulting in the improved compressive performance, remarkable oil absorption capacity, and efficient separation of oil and water. For the PI/MXene-3 aerogel (weight ratio, 5.2:1) without any surface modification, the water contact angle was 119° with a density of 23 mg/cm3. This aerogel can completely recover to its original height after 50 compression–release cycles, exhibiting superelasticity and exceptional fatigue-resistant ability. It also showed high absorption capacities to various organic liquids ranging from approximately 18 to 58 times of their own weight. This hybrid aerogel can rapidly separate the chloroform, soybean oil, and liquid paraffin from the water–oil system. The thermally stable hybrid aerogel also exhibited excellent fire safety properties and outstanding reusability under an extreme environment.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2019
·Vol. 54
·期 12
·8941-8954
·
IF 3.442
Chen Peng,Huang Wenlong,Liu Huitian,Cao Zongjie,Yu Yu,Liu Yuansheng,Shan Zhongqiang
The damage of electrode integrity resulting from large volume change during cycling is the main reason that leads to the fast capacity loss of silicon anodes. Consequently, developing silicon anodes with integrated structure is critical for their practical application. Here, an integrated silicon anode with enhanced cycling ability using polyimide as binder and cyclized polyacrylonitrile as conductive matrix is fabricated by a facile pyrolysis process. The imidization of polyimide and cyclization of polyacrylonitrile are conducted simultaneously during the in situ heat treatment process. Owing to the synergy effect of polyimide binder and conductive polyacrylonitrile which can restrict volume expansion and maintain integrated conducting path effectively, the electrode exhibits a higher initial coulombic efficiency of 83.6% and delivers excellent cycle life with a high reversible capacity of 2362.2 mAh g −1 even after 100 cycles at a current density of 0.1 C, revealing significant improvement in cycle life in comparison with that of Si@cPAN or PI electrode.
✓ 已验证
产品关联
DOI
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.
✓ 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）