Small
·
2025
·
IF 12.1
Jian Zhang,Xinpeng Wang,Xiaomeng Guo,Wenhao Sang,Qing He,Wen Zhang
Metal–organic frameworks (MOFs) with unique pore architectures and electron-rich sites exhibit an unprecedented iodine capture property. In this contribution, the crystal-size and pore-size-dependent iodine adsorption behavior in MOFs ranging in crystal size from nanometers to micrometers with mesoporous and microporous structures is reported. Nano-sized MOFs have much higher iodine adsorption capacities and rates than Micro-sized MOFs. The pore diffusion for iodine adsorption in MOFs is the rate-controlling step and small-sized MOFs can provide larger external surface areas for iodine transport into adsorbents. Raman spectra suggest the diffusion of iodine molecules is more restricted than iodide species in micropores, and the iodine concentration gradient is more significant in microporous MOF-74 than in mesoporous PCN-222. Molecular simulation indicates iodine transports from mesopores to micropores, and aggregates in micropore cages and framework walls. The electron-rich O/N sites in MOFs attract iodine strongly and restrict iodine diffusion, while the weak interaction between iodine molecules becomes prominent at a high iodine loading amount and thus increases the iodine diffusivity in MOFs. The above result reveals a strong size dependence in iodine adsorption behaviors sensitive to MOFs' intrinsic crystal size, porosity, and guest–host interactions, and MOFs with smaller crystal sizes and mesoporous construction have better iodine capture performance.
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
RSC Advances
·
2016
·Vol. 6
·期 22
·18052-18059
·
IF 3.289
Yi-Hua Wang,Qi Shi,Hong Xu,Jin-Xiang Dong
Small- and large-sized crystalline ZIF-71 was synthesized using different strategies and has average diameters of approximately 450 nm, and 1–2 μm. Large-sized ZIF-71 particles with good crystallinity were prepared by a solvothermal synthesis method and small-sized ZIF-71 particles were prepared upon the addition of an acidic additive (formic acid) at room temperature. The two different sizes of particles were used as oil additives in liquid paraffin, and investigated using four-ball tribotesters. The results show that the small-sized particles can improve the anti-wear properties and load-carrying abilities of the base oil. The large-sized particles exhibit good load-carrying capacity. Wear surfaces were analysed by using scanning electron microscopy (SEM), energy dispersive spectrometry (EDS) and Zygo Zegage 3D optical profiler after the wear tests.
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
NEW JOURNAL OF CHEMISTRY
·
2023
·Vol. 47
·期 43
·20157-20170
·
IF 3.3
Xiaojun Dai,Yan Cheng,Tingting Liu,Lingjuan Mao,Ruihua Kang,Qiang Wei,Yasong Zhou
In the process of petroleum refining, realizing the production and utilization of chemical raw materials is the common goal pursued by the petrochemical industry at present. The integration of the refining and chemical industry can not only produce clean fuel, but also meet the demand of the chemical industry for raw materials. In this study, Y zeolites with controllable crystal size and particle size were successfully prepared by simply adjusting the composition of the directing agent. Through a series of characterization, the effects of the composition change of the directing agent on the physicochemical properties of Y zeolites were investigated. Corresponding NiWS supported catalysts were prepared by using synthesized Y zeolites as supports. Taking naphthalene as the model reactant, the effects of crystal size and particle size of Y zeolites on the catalytic performance of the catalyst and on the hydrocracking of naphthalene to C6–C8 products were investigated. The results show that the preparation of small crystal Y zeolites can be realized by simply adjusting the composition of the directing agent, and the corresponding catalyst can realize the efficient production of chemical raw materials. This is expected to provide a simple, economical, feasible, and effective idea for the petrochemical industry to realize the goal of refining and chemical integration.
研究领域:
石油化学工程
·
催化材料科学
✓ 已验证
DOI
高影响因子
Nanomaterials
·
2019
·Vol. 9
·期 2
·220
·
IF 4.034
Guanjie Xing,Xiaoli Liu,Simeng Hao,Xiaohong Li,Louzhen Fan,Yunchao Li
Benefiting from their ultra-small diameters and highly structural anisotropies, ultrathin semiconductor nanowires (USNWs) are well-known for their fascinating physical/chemical properties, as well as their promising applications in various fields. However, until now, it remains a challenge to synthesize high-quality USNWs with well-controlled diameters and lengths, let alone the exploration of their size-dependent properties and applications. To solve such a challenge, we report herein a ligand-induced low-temperature precursor thermolysis route for the controlled preparation of ultrathin ZnS nanowires, which is based on the oriented assembly of the in-situ formed ZnS clusters/tiny particles. Optimized synthetic conditions allowed the synthesis of ZnS nanowires with a diameter down to 1.0 nm and a length approaching 330 nm. The as-prepared ultrathin ZnS nanowires were then intensively examined by morphological, spectroscopic and electrochemical analytical means to explore their size-dependent optical absorption properties, photocatalytic activities and band-edge energy levels, as well as their underlying growth mechanism. Notably, these USNWs, especially for the thinnest nanowires, were identified to possess an excellent performance in both the selective absorption of ultraviolet (UV) light and photocatalytic degradation of dyes, thus enabling them to serve as longpass ultraviolet filters and high-efficiency photocatalysts, respectively. For the ultrathin ZnS nanowires with a diameter of 1.0 nm, it was also interesting to observe that their exciton absorption peak positions were kept almost unchanged during the continuous extension of their lengths, which has not been reported previously.Keywords:ultrathin semiconductor nanowires;size-controlled synthesis;size-dependent optoelectronic properties
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials
·
2020
·Vol. 13
·期 23
·5442
·
IF 3.057
Luqun Liu,Juan Wang,Yunzhu Ma,Wensheng Liu,Shuwei Yao
Continuous alumina fiber exhibits excellent mechanical properties owing to its dense microstructure with fine grains. In this study, alumina fiber was prepared by the sol–gel method using iron sol as a nucleating agent. It was proposed that the α-Al2O3grain size be adjusted based on the modification of colloidal particle size. The effect of holding temperature and reaction material ratio on the iron colloidal particle size was studied. The microstructure of alumina fiber was characterized by scanning electron microscopy (SEM). The experiment results indicated that iron colloidal particle size increases with the holding temperature and the NH4HCO3/Fe(NO3)3·9H2O ratio. The alumina fiber with uniform nano α-Al2O3grains was obtained by calcination at 1400 °C for 5 min. The mean grain size tends to rise with the mean colloidal particle size. Using the iron sol as a nucleating agent, the fiber with a mean grain size of 22.5 nm could be formed. The tensile strength of fibers increased with the decrease of grain size.Keywords:alumina fiber;iron sol;holding temperature;colloidal particle size;grain size
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
NANO
·
2017
·
IF 1.025
Longfeng Li,Chengyu Li,Mingzhu Liu,Cheng Wang
The catalytic performance of ceria oxide (CeO 2 ) was greatly influenced by the materials’ structure and surface area. In this paper, CeO 2 porous nanospheres (PNS) with tunable pore and sphere sizes were synthesized by a solvothermal method using diethylene glycol as reaction media. All the as-synthesized CeO 2 PNS presented good adsorption capacity for methyl orange, which makes them potential application in waste water treatment conveniently and economically. The control over the sphere and pore sizes of CeO 2 PNS was achieved by regulating the volume of water bubble in the reaction system, which supplied limited room for the assembling of preformed CeO 2 small nano-precursors.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Chao Li,He Kang,Ai Wang,Boai Zhang,Yijun Cao
Fluidized-bed flotation is a novel process with combined features of flotation and density separation. The application of fluidized-bed flotation in grinding circuit to reject coarse gangues for sulfide ores has been increasingly attracting attentions. Previous studies have focused on the effect of mineral liberation on coarse particle separation. Little work has yet been conducted to simultaneously investigate the effect of mineral liberation, particle and bubble sizes on the fluidized-bed flotation efficiency. The lack of this work has hindered the process optimization to some extent. In this study, three sizes of bubbles (498 μm, 1200 μm, 1952 μm) were generated to separate molybdenite ores under three particle size fractions (150–450 μm, 450–700 μm and 700–1000 μm) in a fluidized-bed flotation column (80 mm in diameter). For the 150–450 μm and 450–700 μm particles, small bubbles of 498 μm could achieve separation by effectively reducing the particle density. For the 700–1000 μm particles with greater mass, intermediate bubble of 1200 μm was required to reduce the particle density for separation. No separation was observed for the three particle size classes with the oversized bubbles of 1952 μm due to high bubble detachment probability. It was concluded that fluidized-bed flotation is a consequence of matched bubble and particle sizes affected by the exposure rate of hydrophobic mineral and its distributing discreteness, the underlying mechanism for which was discussed. It is believed that the outcomes of this work could facilitate the optimization of fluidized-bed flotation in coarse gangue rejecting for sulfide ores.
研究领域:
矿物加工
·
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER
·
2024
·
IF 4.1
Jingyao Feng,Danhui Wang,Nan Li,Heming Wang,Ning Wang,Bing Wang,Shan Cheng,Qingguang Bao,Jiangang Liu,Xiaonan Shi,Mengting Li,Xigao Jian
In this study, a series of high temperature resistant water-soluble thermoplastic sizing agents were designed and synthesized to improve the interfacial bonding of CF/PPESK composites. The effects of the ratio of water-soluble functional monomer (PPL) and high temperature resistant monomer (DHPZ) on the performance of the pastes were investigated. The results showed that the sizing agent with PPL: DHPZ = 6: 4 had the best performance, and its thermal decomposition temperature was up to 348 °C, which met the requirements of the composite molding process. The ILSS and flexural strength reached the peaks of 67.2 MPa and 1526.5 MPa. The retention rates were 89.7 % and 81.8 %, respectively, after hydrothermal aging treatment, compared with 77.7 % and 79.2 % for the epoxy sizing agent. The bottleneck of traditional epoxy sizing agent and CF/PPESK composites molding process mismatch has been broken.
研究领域:
材料科学
·
复合材料工程
✓ 已验证
产品关联
DOI
高影响因子
Nanoscale
·
2013
·Vol. 5
·期 24
·12335-12341
·
IF 6.233
Songping Wu,Zhuolin Wang,Xin Ouyang,Zhiqun Lin
Size-tunable crystalline core–crystalline shell Zn2GeO4 nanorods were synthesized via a facile hydrothermal reaction. High purity Zn2GeO4 nanorods were obtained at pH = 7. The length of Zn2GeO4 nanorods (L = 50–100 nm) can be controlled through a one-step process, while micro-sized nanorods with an aspect ratio of the length to the diameter of 10 were yielded in a two-step process. The single crystalline nature of Zn2GeO4 nanorods with a core–shell structure was verified by high resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED) measurements. The Raman study revealed that there is no oxygen defect in Zn2GeO4 nanocrystals, suggesting that photoluminescence emission of Zn2GeO4 can be attributed to the presence of the interstitial Zn defect in Zn2GeO4 nanocrystals. As the diameter of nanorods decreased, the excitation and emission peaks appeared to be redshifted due to the quantum size effect.
研究领域:
材料科学
·
纳米技术
·
材料的光学性质
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2022
·Vol. 57
·期 25
·11537-11545
·
IF 4.682
Chen Chuan,Zhang Qiang,Yao Tianhao,Wang Hongkang
Nickel-copper-zinc (NiCuZn) ferrites are widely used in high-frequency fields due to their low eddy current losses as well as high resistivity, but which are greatly affected by their microstructures, such as porosity, grain size. Herein, we report a novel synthesis of shuttle-shaped NiCuZn ferrites through electrospinning and subsequent sintering. The microstructural evolution and its effect on magnetic properties upon annealing at temperatures ranging from 500 to 1000 °C are systematically investigated through X-ray diffraction, Raman spectroscopy, scanning electron microscopy, and vibrating sample magnetometry. The results demonstrate that the average crystallite size of NiCuZn ferrites decreases and the grain size rises with increasing the sintering temperature. Meanwhile, the saturation magnetization shows an upward trend upon increasing the sintering temperature and reaches the highest value of 68.07 emu g −1 at 900 °C. However, when further increasing the sintering temperature to 1000 °C, the crystalline structure, as well as the morphology of the NiCuZn ferrite, change a lot with coarse particle growth/aggregation, thus resulting in lowered saturation magnetization. Inductively coupled plasma mass spectrometer analysis shows that the stoichiometric ratios of NiCuZn ferrite change with the sintering temperature, which also affects the magnetic properties. More importantly, this study demonstrates that electrospinning is promising to fabricate well-defined nanostructured ferrites with tunable components, morphologies, and magnetic properties.
研究领域:
材料科学
·
纳米技术
·
磁学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2018
·
IF 3.057
Xiangquan Wu,Qin Lian,Dichen Li,Xiaoning He,Jiali Meng,Xiaodong Liu,Zhongmin Jin
Mask projection stereolithography can be used to fabricate complex ceramic parts layer by layer through the photopolymerisation of ceramic suspensions. The broadening or lateral overcure of the curing shape occurs because of light scattering effects. Achieving a better dimension and strength quality by adjusting light energy delivery in the boundary mask area has been insufficiently investigated thus far. In this study, the conventional mask was segmented into boundary and interior masks. The exposure time and power of the boundary mask (two pixels wide) were varied to investigate the effects of segmented exposure. The segmented exposure constrained the dimension errors to a width of within two pixels for a feature dimension of less than 1200 µm. It further smoothed the lateral surface of the green part to achieve Ra values of below 6 µm. Moreover, enhancing the boundary mask increased the flexural strength and Weibull modulus to 248 MPa and 11.1, respectively. The results indicate that segmented exposure can potentially be used in complex lattice ceramic structures.
研究领域:
生物医学工程
·
材料科学
·
增材制造
✓ 已验证
DOI
高影响因子
HOLZFORSCHUNG
·
2018
·Vol. 73
·期 5
·469-474
·
IF 2.079
Yaoge Huang,Gaiyun Li,Fuxiang Chu
Poplar wood samples (2×2×2 cm 3 ) were vacuum/pressure impregnated in alcoholic solution with 2-hydroxyethyl methacrylate (HEMA) and 3-(methacryloxy)propyltrimethoxysilane (MAPTES) in a mass ratio of 3/1 in the presence of catalytic amounts of azobisisobutyronitrile (AIBN). Because of their good solubility and permeability, the HEMA/MAPTES precursors evenly penetrate the poplar cell wall. The impregnated samples were heated at 75°C for 8 h, followed by a heating period at 103±2°C for 8 h, in the course of which an in situ polymerization occurred in the cell wall. The modified wood was characterized by Fourier transform infrared (FTIR) and Raman spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). Moreover, the dimensional stability of the modified wood was measured and found to be considerably improved.
研究领域:
材料科学
·
木材科学
✓ 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）