JOURNAL OF APPLIED POLYMER SCIENCE
·
2023
·Vol. 140
·期 37
·e54400
·
IF 3
Xiaowei Jiang,Zhihong Liu,Yujiao Tan,Xiaosong Chen,Ping Huang,Libo Ma,Xu Xiong,Weibin Gao,Yu Tao,Hongxia Lu,Zheng Dai
Nitrogen atoms has been widely adopted in preparation of porous organic polymers (POPs). In our study, flexible nitrogen porous organic polymers (FNPOPs) with high nitrogen content are synthesized by using acetic acid both as solvent and catalyst. The materials show moderate Brunauer–Emmett–Teller (BET) surface area and outstanding thermal stabilities ( T d : 330°C). FNPOP-2 is prepared into phase change material (PCM) composites by self-adsorption method. From differential scanning calorimetry (DSC) analysis, the PCM composites show high encapsulation ratio (55.2 wt%) and latent heat (135.7 J g −1 ) due to flexible structure and high nitrogen atomic content. Furthermore, the thermal energy storage properties of all PCM composites remained after several thermal cycles. In general, FNPOPs have potential applications in phase change materials adsorption and thermal energy storage.
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FUEL
·
2022
·
IF 8.035
Hu Liu,Jingwen Xue,Pengfei Yu,Yankang Zhang,Jinhua Wang,Defu Che
Hydrogen is a clean secondary energy as well as an efficient energy carrier, but the low density and small molecular hydrogen result in high economic and energetic efforts to store and transport hydrogen. In addition, the hydrogen produced by the current industry is usually impure and requires gas separation, which consequently increases the cost of hydrogen. A promising hydrogen storage technology using liquid organic hydrogen carrier (LOHC) can permit the safe storage of hydrogen for long time through the reversible chemical reaction in the presence of catalyst. The selective hydrogenation reaction of N -ethylcarbazole (NEC), an attractive LOHC compound due to the low dehydrogenation temperature of perhydro- N -ethylcarbazole (12H-NEC), with hydrogen was conducted in this study to achieve both separation and hydrogen storage for hydrogen-rich raw gas from natural gas steam reforming. First, hydrogenation experiments of molten NEC under a pure hydrogen atmosphere were carried out to determine the suitable hydrogenation conditions and reaction pathways. Then, the effect of methane addition on NEC hydrogenation was analyzed. Results indicate that there are multiple parallel pathways in the hydrogenation of NEC. The reaction rate from 8H-NEC to 12H-NEC step is extremely slow and this step is unstable at 453 K. The optimal hydrogenation temperature of NEC is 443 K and the apparent activation energy is 67.6 kJ·mol −1 . The addition of methane reduces the initial reaction rate from 0.877 g H2 ·(g Ru ·min) −1 to 0.640 g H2 ·(g Ru ·min) −1 but increases the maximum degree of hydrogenation ( DoH ) from 0.870 to 0.909.
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JOURNAL OF THE ENERGY INSTITUTE
·
2022
·
IF 6.47
Xuan Zhao,Dandan Qi,Kaixuan Yang,Chen Chen,Lei Xu,Yaoyao Ying,Tianjiao Li,Dong Liu
This work focused on effects of n- butanol addition on sooting transition process in iso -octane counterflow diffusion flames using optical and chemical diagnostics. Three iso -octane flames were studied with pure iso -octane, a 20% n- butanol addition mixture and a 40% n- butanol addition mixture as fuels. Optical diagnostics was carried out to determine effects of n -butanol addition on the sooting transition process using a high-resolution digital camera based on image processing and transition point extraction methods. Online gas chromatograph was used to investigate the flame chemistry in the sooting transition process. The results showed that the sooting transition point was delayed with the increase of n -butanol addition, which indicated that the addition of n -butanol could suppress the soot formation. To reveal the mechanism for effects of n -butanol on sooting transition process, kinetic simulations were further performed. The experimental results of flame chemistry were compared with the predictions from two mechanisms for iso -octane and n -butanol mixture. Both mechanisms were found to be capable of well capturing the main variations of most species in flames. After n -butanol addition, the changes of fuel-specific primary decomposition products were more obvious. It was noted that the decreased concentration of carbon which was available for benzene formation was the main reason for the delay of sooting transition point with n -butanol additions. Moreover, the inhibition of PAHs growth from n -butanol addition also could contribute to this kind of delayed effects.
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Nano Energy
·
2022
·
IF 19.069
Sijing Liu,Yuewang Yang,Shusheng Chen,Jiongzhi Zheng,Dong Gyu Lee,Dan Li,Jinglei Yang,Baoling Huang
Flexible ionic thermoelectric materials with large thermopowers show great promise for ultrasensitive thermal detection in wearable devices . Here large and tunable p- and n-type thermopowers are reported in stretchable and self-healing ionogels made of a fluorocarbon elastomer poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), an ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMIMTFSI) and a salt acting as the thermopower regulator. Particularly, a self-healing n-type ionic thermoelectric material is developed for the first time. The thermopower of the resultant ionogels varies from + 30 mV K −1 to − 21 mV K −1 at 90% relative humidity. Meanwhile, the ionogels exhibit excellent stretchability up to 1700% and appropriate Young’s modulus of around 0.26 MPa. Both the mechanical and thermoelectric properties can self-heal spontaneously after damage. Taking advantage of the large p and n-type thermopowers, the stretchable self-healing ionogels are integrated as a flexible thermoelectric detector with 10 pairs of p- and n-type legs on copper electrodes, showing a total thermopower of 0.25 V K −1 operating with a low temperature difference of 1–2 K.
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COMBUSTION AND FLAME
·
2022
·
IF 5.767
Bingjie Chen,Peng Liu,Qiang Xu,Zhandong Wang,William L. Roberts,Heinz Pitsch
As an important component of transportation fuels, toluene has little reactivity in the low temperature regime. However, the low temperature reactivity of toluene may be enhanced by the reaction of other reactive components (e.g., n-heptane) in fuel mixtures. This work examines low temperature oxidation of toluene in jet stirred reactor oxidation of an n-heptane/toluene mixture (1:1 in mole, 500–800 K, ϕ=0.5, τ=2.0 s, p = 1 bar). Two measurement techniques, time of flight molecular beam mass spectrometry using synchrotron vacuum ultraviolet radiation as the photon ionization source and gas chromatography mass spectrometry, were applied to identify and measure 32 species, including four polycyclic aromatic hydrocarbons (PAH) and oxygenated PAH (OPAH). Numerical simulations using the latest kinetic model from Lawrence Livermore National Laboratory predicted the mole fractions of fuel molecules and small intermediates well, but under-predicted the mole fractions of oxygenated aromatics (phenol, benzyl alcohol, and cresol). The identification of benzyl peroxide–an important intermediate–supported the proposed formation pathways for the identified aromatics. Model analysis highlighted the influence of H-atom abstraction, OH/H radical ipso substitution, and OH addition reactions of toluene on the formation of phenol , benzyl alcohol, and cresol, which may further grow to OPAH molecules by the addition of benzyl radical from H-atom abstraction of toluene.
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International Journal of Polymer Science
·
2022
·
IF 2.973
Runan Gao,Ying Shang,Peng Jiao,Yue Jiao,Jian Li,Yun Lu
The novel wettability switchable cellulose nanofiber- (CNF-) based aerogel was conveniently prepared by polydopamine mediated composition of CNF and n-dodecanethiol. The wettability of aerogels can be controlled by adjusting the PDA and n-dodecanethiol loading content, which leads to a variation of water contact angle from 0-149°. The PDA was coated on cellulose nanofibers via hydrogen bonds and then n-dodecanethiol was anchored onto the scaffolds by Michael addition reaction, which was revealed by XPS and FTIR spectra. The composite aerogel can selectively absorb a series of oily liquids from the oil/water mixture, with the maximum absorption capacity of 68 g/g. This work presented a facile strategy to prepare wettability switchable CNF-based heterogenous aerogel and exhibited the potential of the composite aerogel for oil/water separation.
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ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Rundong Guo,Dong Su,Fu Chen,Yongzhi Cheng,Xian Wang,Rongzhou Gong,Hui Luo
Microwave-absorbing materials have attracted enormous attention for electromagnetic (EM) pollution. Herein, hollow beaded Fe3C/N-doped carbon fibers (Fe3C/NCFs) were synthesized through convenient electrospinning and subsequent thermal treatment. The special hollow morphology of the samples is conducive to achieve lightweight and broadband microwave absorption properties. The thermal treatment temperatures exhibit a significant impact on conductivity and EM properties. The broadest effective absorption bandwidth (EAB) is 5.28 GHz at 2.16 mm when the thermal treatment temperature is 700 °C, and the EAB can cover 13.13 GHz with a tunable absorber thickness from 1.0 to 3.5 mm when the thermal treatment temperature is 750 °C. The excellent microwave absorption properties of the samples are due to the synergistic effect of impedance matching and strong EM energy attenuation abilities. Hence, the magnetic hollow beaded Fe3C/NCFs are expected to be an attractive candidate material as a lightweight and efficient microwave absorber in the future.
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高影响因子
MOLECULES
·
2021
·Vol. 26
·期 22
·6849
·
IF 4.412
Yan Fan,Tao Wang,Yinwei Qiu,Yinli Yang,Qiubo Pan,Jun Zheng,Songwei Zeng,Wei Liu,Gang Lou,Liang Chen
Graphene p-n junctions have important applications in the fields of optical interconnection and low–power integrated circuits. Most current research is based on the lateral p-n junction prepared by chemical doping and other methods. Here, we report a new type of pure graphene oxide (pGO) vertical p-n junctions which do not dope any other elements but only controls the oxygen content of GO. The I–V curve of the pGO vertical p–n junction demonstrates a remarkable rectification effect. In addition, the pGO vertical p–n junction shows stability of its rectification characteristic over long-term storage for six months when sealed and stored in a PE bag. Moreover, the pGO vertical p–n junctions have obvious photoelectric response and various rectification effects with different thicknesses and an oxygen content of GO, humidity, and temperature. Hall effect test results show that rGO is an n–type semiconductor; theoretical calculations and research show that GO is generally a p–type semiconductor with a bandgap, thereby forming a p–n junction. Our work provides a method for preparing undoped GO vertical p–n junctions with advantages such as simplicity, convenience, and large–scale industrial preparation. Our work demonstrates great potential for application in electronics and highly sensitive sensors.Keywords:undoped p–n junction;vertical p–n junction;graphene oxide
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Journal of Materials Chemistry C
·
2020
·Vol. 8
·期 11
·3694-3704
·
IF 7.059
Chen Li,Xin Chen,Ning Li,Jialiang Liu,Beilei Yuan,Yujiao Li,Mei Wang,Fan Xu,Yangqing Wu,Bingqiang Cao
Highly conductive n-type bismuth-doped CH3NH3PbI3 (MAPbI3:Bi) single crystals are successfully grown by the inverse temperature crystallization (ITC) method using bismuth iodide as the dopant source. As revealed by XRD analysis, the Bi-doped MAPbI3 single crystals maintain a perfect cubic perovskite structure (Pmm). Bi3+ ions are successfully incorporated into the MAPbI3 crystal lattice, which induces three orders of magnitude enhancement in the n-type electrical conductivity in a controllable way. Clear Urbach tails in the optical absorption spectra and continuous blue shifts in the room-temperature photoluminescence (PL) spectra are both observed after bismuth doping, which indicates the formation of bismuth induced donors and the release of more electrons to the conduction band. Temperature-dependent PL (TDPL) studies are adopted to study the optical fingerprints of bismuth induced donor defects in the MAPbI3 crystals. By analyzing the TDPL spectra in detail, it is found that the bound exciton (D0X) peak in doped MAPbI3:Bi has a stronger relative intensity and also a significant redshift in comparison with the pristine MAPbI3 crystal. This indicates that stable donor levels are formed in MAPbI3:Bi single crystals by bismuth doping. These results suggest that n-type perovskite crystals have been realized in a controlled doping way, and potential applications in bipolar perovskite-based optoelectronic devices could be realized.
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Environmental Science-Processes & Impacts
·
2023
·Vol. 25
·期 12
·1962-1973
·
IF 5.5
Jine Wang,Chen Zhang,Rui Zhao,Pei Wang,Meihua Jin,Jiujun Xu
Marine biofouling is a thorny issue that causes serious economic losses and adverse ecological impacts on marine ecosystems. Effective and promising antifouling strategies such as surface hydration, flow shear force, and lubricant injection have been developed to address this challenge. However, for the complex marine environment, they still appear inadequate. Mussels are a common fouling organism with strong surface adhesion ability. However, when hypoxia and the oxidative cross-linking reaction of 3,4-dihydroxy phenyl-L-alanine (DOPA) in the structure of adhesion proteins are disrupted, their adhesion ability will be greatly reduced. Inspired by this, we developed an effective antifouling strategy based on reactive oxygen species (ROS) scavenging using N-acetylcysteine (NAC) and evaluated its performance. As a ROS scavenger interfered with the oxidative cross-linking reaction of DOPA in an aqueous solution, the adhesion of DOPA was also affected on the surface of NAC functionalized polyvinyl chloride (PVC) (PVC-NAC). In addition, the colonization level of mussels and the adhesion rate of marine bacteria and benthic diatoms on PVC-NAC were low. The antifouling strategy proposed in this paper was eco-friendly and broad-spectrum, and may provide a new idea for solving marine biofouling and reducing the environmental and economic impacts of fouling organisms.
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EUROPEAN POLYMER JOURNAL
·
2023
·
IF 6
Jun Li,Peng Huang,Xiangbin Sun,Xue Bai,Yufeng He,Rongmin Wang
Conventional N-halamine precursor polymers with excess hydrophilic/hydrophobic and rigid/flexible groups have failed to achieve a co-balanced effect of amphiphilicity and rigidity-flexibility. To overcome this problem, hydantoin terpolymer nanohemispheres (P(AMH-St-BA)NHs) were synthesized by regulating both hydrophilic/hydrophobic and rigid/flexible group ratios to 1:1 using emulsion polymerization. Thereafter, a novel N-halamine terpolymer nanohemisphere (P(ClA-St-BA)NHs) with antibacterial activity was fabricated through chlorination treatment. Interestingly, chlorinated nanohemispheres were more dispersed and regularly shaped. Moreover, the effective chlorine content (Cl + ) of P(ClA-St-BA)NHs was detected to be 1.1 % by iodometric/thiosulfate titration, and the existence of N-Cl bonds was supported from the color change of titration. In vitro cytotoxicity suggested that P(AMH-St-BA)NHs possessed superior biocompatibility and safety. Additionally, the antimicrobial performance of samples with three various morphologies was investigated, discovering that the antibacterial rates of P(ClA-St-BA)NHs up to 89.5 % and 93.5 % against E. coli and S. aureus , respectively, exhibited a stronger antimicrobial capability than membranous and porous N-halamine copolymers, which reveals that their special shape elevates the property. In parallel, the antibacterial mechanism of nanohemispheres was also explored, and it was recognized that indirectly released Cl + synergizes with direct contact of N-Cl bonds for antibacterial purposes. By designing nanohemispheres, this method helps to provide new thoughts for realizing the co-balancing effects of hydrophilicity/hydrophobicity and rigidity/flexibility.
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RSC Advances
·
2021
·Vol. 11
·期 14
·7954-7960
·
IF 3.361
Jianxin Chen,Peng Miao,E. Emily Lin,Ting Bai,Stoyan K. Smoukov,Jie Kong
Microwave absorbents with specific morphology and structure have fundamental significance for tuning microwave absorption (MA). Herein, N-doped carbon sphere nanoparticles and hollow capsules were successfully fabricated via oxidative polymerization of dopamine in different mixed solutions, without any template preparation or etching process. Compared to solid particles, the microwave absorbents consisting of N-doped carbon with a hollow structure showed enormously enhanced MA performance, exhibiting a broad effective absorption bandwidth (from 12.7 GHz to 17.9 GHz) and a minimum reflection loss of −27.2 dB with a sample thickness of 2.0 mm. This work paves an attractive way for simple and eco-friendly preparation of advanced light weight microwave absorbents.
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