Advanced Intelligent Systems
·
2019
·Vol. 1
·期 7
·1900064
·
IF 0
Daolin Wang,Zhihua Lin,Chang Zhou,Changyong Gao,Qiang He
One of the great challenges in the field of tiny machines is the capability of engineering liquid metal micromachines to autonomously move within confining channels to perform various complex tasks. Herein, liquid metal gallium micromachines that significantly increase their velocity in confining channels with adaptive deformation under exposure to an electric field are presented. The liquid metal gallium micromachines move toward the negative electrode under the propulsion of hydrogen bubbles, which is obviously different from the previous report that liquid metal gallium alloy (i.e., Galinstan) micromachines move to the positive electrode, owing to the surface tension gradient. More importantly, the liquid metal gallium micromachine can adaptively deform and accelerate in confined channels. The velocity of liquid metal gallium micromachines increases with the decrease in the width of channels. It is found that the speed-up motion of liquid metal gallium micromachines is caused by the enhanced electro-osmosis effect in confining channels. The findings not only help understand the role of the confinement effect on the motion of liquid metal micromachines but also provide a novel strategy to manipulate the motion velocity of liquid metal micromachines for specific applications.
研究领域:
材料科学
·
微纳米技术
·
物理学
✓ 已验证
产品关联
DOI
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2021
·
IF 3.171
Shuo Li,Jianlin Cao,Xiang Feng,Yupeng Du,De Chen,Chaohe Yang,Wenhua Wang,Wanzhong Ren
Elucidating the confinement effect harbours tremendous significance for isobutane alkylation with C 4 olefin . Herein, the confinement effect over zeolite catalysts was elucidated by combining DFT calculations, experiments (using the novel Beta zeolite exposing only external surfaces (Beta-E) and conventional Beta-I zeolite with both external and internal surfaces) and multi-techniques ( e . g ., TGA-DTG, HRTEM, SEM and XRD). It is found that the main active sites for C 4 alkylation reaction are located on internal surface rather than external surface. On the external surface, the hydride transfer reaction does not occur because the H-shared intermediate cannot be formed without the confinement effect. Moreover, the external surface has stronger selectivity for C 4 olefin adsorption than isobutane, leading to enhanced oligomerization reactions. Therefore, the suitable micropore with confinement effect is essential for zeolite-catalyzed C 4 alkylation. The atomic-scale insights of this work are of great referential importance to the design of highly effective zeolite catalyst.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
THERMOCHIMICA ACTA
·
2018
·
IF 2.189
Shuping Deng,Dongqing Wang,Xin Wang,Yongteng Wei,Geoffrey I.N. Waterhouse,Xiao Zheng Lan
The effect of nano-confinement on the phase transitions of heneicosane ( n -C 21 H 44 , C 21 ) were investigated using differential scanning calorimetry (DSC) and variable temperature powder X-ray diffraction (XRD). When C 21 is confined within the pores of controlled pore glasses (CPGs), SBA-15 or other mesoporous materials, the solid-solid ( T s ) and solid-liquid ( T m ) transition temperatures are depressed. The depression of the phase transition temperatures (Δ T s , Δ T m ) for C 21 in CPGs and SBA-15, the degree of supercooling and enthalpy change (Δ H s , Δ H m ) for C 21 in CPGs, exhibited a linear dependence on the inverse pore size. The Δ T m values were insensitive to the polarity pore wall but varied with the pore geometry. XRD analysis revealed that the lamellar ordering characteristic for the solid C 21 was disturbed in the nanopores, with the extent increasing as the pore size decreased. A new rotator phase R II is found for C 21 confined in CPG (12 nm) and SBA-15 (14.4 nm).
研究领域:
材料科学
·
物理化学
✓ 已验证
DOI
高影响因子
Journal of Energy Chemistry
·
2020
·
IF 7.216
Tao Jiang,Peng Lu,Meng-Jiao Xu,Jian-Dong Lin,Yong-Mei Liu,Yong Cao,He-Yong He
We describe herein that the quasi-one-dimensional confinement effect of functionalized nanoporous supports is particularly advantageous for boosting formic acid (FA) dehydrogenation efficiency over palladium nanoparticles (NPs). Benefiting from their unique structural merits that lead to significant lowering of the entropic barrier for FA activation, the Pd NPs interiorly located on the amino-modified MCM-41 offer the promise of more than an order of magnitude speedup of the initial activity in H 2 production from FA over their exterior analogs. Under mild and additive-free conditions, ultrafine Pd NPs confined in amino-modified MCM-41 channels exhibit an initial turnover frequency as high as 46,677 h −1 and a turnover number up to 1,060,000 at 60°C. In conjunction with the enhancement and robust performance for efficient regeneration of FA via CO 2 hydrogenation, the presented approach greatly contributes to the development of FA-based hydrogen storage and related technologies as viable means of enabling sustainable future energy prospects.
研究领域:
化学
·
能源材料科学
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2018
·Vol. 28
·期 41
·1804150
·
IF 13.325
Zhichao Zhang,Chonggeng Ma,Romain Gautier,Maxim S. Molokeev,Quanlin Liu,Zhiguo Xia
Structural confinement effect on a pair of Eu 2+ and Mn 2+ optical centers is developed to realize the greatly enhanced red emission attributed to the 4 T 1 ( 4 G)– 6 A 1 ( 6 S) transition of Mn 2+ ions. Sr 9 Mn 1.26(2) Li 0.24(2) (PO 4− δ ) 7 , when it is doped with Eu 2+ , emerges as a new red-emitting phosphor, and the intensity dependence of such a red emission on the trace amounts of Eu 2+ doping is quantitatively analyzed with a combined experimental and theoretical methods. The modeling result confirms the validity of this proposed design strategy, and the intrinsic high-efficient Eu 2+ –Mn 2+ energy transfer process can be elucidated by the structural confinement effect featured as some Sr (Eu) close to Mn atoms. The results can initiate the exploration of Mn 2+ -based red phosphors for pc-white light-emitting diodes applications, and such a strategy can be easily expanded to other systems, thus opening a new perspective for the development of luminescence materials.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2019
·
IF 5.155
Chunyu Sun,Xinzhan Wang,Yanmei Xu,Wanbing Lu,Xiaoyun Teng,Guangsheng Fu,Wei Yu
CsPbI 3 nanocrystals (NCs) with photoluminescence quantum yield (PLQY) larger than 90% have been synthesized at different temperature regions, and the physical origins for high PLQY were investigated. HRTEM images show that cubic phase CsPbI 3 (α-CsPbI 3 ) is surrounded by hexagonal Cs 4 PbI 6 in the low temperature region, and the ratio of CsPbI 3 and Cs 4 PbI 6 increases with increasing the reaction temperature. The strong confinement effect of Cs 4 PbI 6 leads to the high PLQY (95%) of α-CsPbI 3 NCs when the reaction temperature is 120 °C. The confinement effect of Cs 4 PbI 6 is weakened with increasing reaction temperature, which leads to the decrease of PLQY at 140 °C. However, non-radiative recombination is suppressed due to the microstructure improvement with further increasing the reaction temperature, and PLQY as high as 97% is achieved at 180 °C. Stability testing shows that fast degradation of α-CsPbI 3 NCs occur in low reaction temperature region, and α-CsPbI 3 NCs with high PLQY can be stored in air for 90 days when the reaction temperature is 180 °C.
研究领域:
材料科学
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
Small
·
2023
·
IF 13.3
Xi Yu,Zhenxing Fang,Siyuan Lin,Shuyue Wu,Mei Fang,Haipeng Xie,Deming Kong,Conghua Zhou
Polyvinyl pyrrolidone is blended in PbI 2 with varied concentration, so as to study the coarsening dynamics of perovskite during the two-step growth method. It is observed that polyvinyl pyrrolidone hinders the crystallization of PbI 2 and helps to form a more amorphous PbI 2 matrix, which then improves perovskite crystallization. As the blending concentration increases from 0 to 2 mM, average crystallite/grain size of perovskite increases from 40.29 nm/0.79 µm to 84.35 nm/1.02 µm while surface fluctuation decreases slightly from 25.64 to 23.96 nm. The observations are caused by the “confinement effect” brought by polyvinyl pyrrolidone on PbI 2 . Elevating blending concentration of polyvinyl pyrrolidone results in smaller PbI 2 crystallites and more amorphous PbI 2 matrix, thus reducing the diffusion/reaction barrier between PbI 2 and organic salt and favoring perovskite crystallization. As blending concentration increases from 0 to 2 mM, the device efficiency rises from 19.76 (± 0.60) % to 20.50 (± 0.89) %, with the optimized value up to 22.05%, which is further improved to 24.48% after n-Octylammonium iodide (OAI)-basing surface modification. The study enlarges the scope of “confinement effect” brought by polymer molecules, which is beneficial for efficient and stable perovskite solar cell fabrication.
研究领域:
材料科学
·
太阳能电池技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Advanced Optical Materials
·
2024
·Vol. 12
·期 19
·2400193
·
IF 8
Dongying Fu,Yanli Ma,Zhuo Chen,Zuoming Hou,Junhua Luo
Lead-free hybrid perovskites (HPs) are considered as environmentally friendly photodetection materials. However, there are few studies on self-powered photodetection in lead-free HPs, and most of them are achieved through the introduction of chiral ammonium cations induced bulk photovoltaic effect (BPVE). Notably, enantiomeric pure chiral ammonium cations are difficult to synthesize, the quantity is small and the price is high. Therefore, choosing achiral ammonium cations to induce BPVE in lead-free HPs is crucial. Herein, achiral cations 1,3- bis (aminomethyl)cyclohexane (1,3-BMACH) is exploited to induce bulk photovoltaic through confinement effect in (1,3-BMACH)BiI 5 , then self-powered X-ray detection is successfully realized. Due to the large space in zero-dimensional (0 D) (MXD)BiI 5 (MXD is meta-xylylenediammonium), the confinement effect is not obvious, resulting in the disorderly arrangement of MXD 2+ cations and a centrosymmetry structure of (MXD)BiI 5 . Benefiting from the large photovoltage (1.0 V) of (1,3-BMACH)BiI 5 under X-ray, its single crystal devices exhibit ultra-high sensitivity of 170 µC Gy −1 cm −2 and extremely low detection limit of 49 nGy s −1 under self-powered mode, which almost surpassing most low-dimensional single-phase lead-free HPs at 0 V bias. This work has promoted the application of lead-free HPs in the field of self-powered X-ray detection.
研究领域:
材料科学
·
光电子学
✓ 已验证
产品关联
DOI
高影响因子
CARBON
·
2020
·
IF 8.821
Ping Wang,Dongxiao Zheng,Shouxin Liu,Mengkai Luo,Jian Li,Shen Shen,Shujun Li,Liangliang Zhu,Zhijun Chen
Embedding luminogens into a well-selected rigid matrix has been a particularly attractive way of preparing long afterglow materials. On this basis, seeking green, low-cost and sustainable materials or strategies, remains challenging but desirable. Prompted by the generation of wood fluorescence, a general strategy for preparing long afterglow materials successfully developed by embedding biomass-derived carbon dots into cellulose fibrils. Internal hydrogen bonding interactions between cellulose fibrils and carbon dots strongly erected a confinement effect for protecting the triplet exciton from quenching, leading to an increase of phosphorescence lifetime by seven orders of magnitude. These properties, which originated from such a green and convenient approach, were able to match most of reported long afterglow examples. Moreover, thanks to the humidity sensitivity of cellulose, the materials can behave a unique humidity-dependent phosphorescence property, showing superior potential application in advanced anti-counterfeiting and encryption.
研究领域:
材料科学
·
可持续发展
·
光学材料
✓ 已验证
产品关联
DOI
高影响因子
Micromachines
·
2022
·Vol. 13
·期 3
·443
·
IF 3.523
Nur Diyana Halim,Muhammad Safwan Zaini,Zainal Abidin Talib,Josephine Ying Chyi Liew,Mazliana Ahmad Kamarudin
The temperature dependence of photoluminescence (PL) emission is a valuable tool for investigating carrier localization, recombination, and carrier–phonon interactions. Herein, electron–phonon couplings in lead sulfide (PbS) quantum dots (QDs) and lead sulfide/manganese tellurite (PbS/MnTe) QDs is reported. The effect of temperature on the PL emission of PbS and PbS/MnTe was explored within a temperature range of 10 to 300 K. When temperature increased, PL emission was blue-shifted due to the confinement effect. The gradual broadening of the full width at half maximum (FWHM) with increasing temperature indicates electron–phonon interactions. An analysis based on the Boson model revealed that the values of the exciton acoustic phonon coupling coefficient, σ, and temperature-dependent linewidth, γ, for PbS/MnTe were larger than those for PbS, indicating stronger exciton longitudinal-optical–phonon coupling in the compound structure.Keywords:electron–phonon coupling;confinement;photoluminescence;quantum dots
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
·
2023
·Vol. 98
·期 5
·1166-1174
·
IF 3.4
Min Yuan,Zhiqing Liu,Tiantian Lv,Jinxiang Dong,Qi Shi
BACKGROUND The separation of furfural from a low-concentration multicomponent and acid-containing aqueous solution is a highly demanding process; traditional distillation requires an excessive amount of energy. Herein, we demonstrated ZIF-8-derived microporous carbon (C) as a promising adsorbent for the separation of furfural using adsorption isotherms, dynamic column adsorption, adsorption kinetics and desorption studies. RESULTS In the competitive adsorption kinetics experiments with a furfural/acetic acid concentration of 50/20 g L −1 , the acetic acid adsorbed in the micropores of NC ZIF-8 1000C-800A gradually was replaced by furfural, whereas the amount of acetic acid in the mesopores of NC ZIF-8 800C-800A slowly increased. In addition, the micropores of NC ZIF-8 1000C-800A exhibited highly efficient and fast adsorption characteristics toward furfural over a wide furfural/acetic acid concentration range (0–50/0–20 g L −1 ) with the furfural adsorption capacity reaching an adsorption equilibrium within 10 min. The results show that the high Brunauer–Emmett–Teller surface area of NC ZIF-8 1000C-800A is responsible for the high furfural adsorption capacity (1205.3 mg g −1 ) and the confined microporous structure can strengthen the π–π interactions between porous C and furfural, thereby enhancing the selectivity of furfural/acetic acid (61.4) in the furfural/acetic acid (50/20 g L −1 ) dynamic column adsorption system. Meanwhile, the desorption ratio of furfural in the dynamic desorption system reached as high as 98.6%. CONCLUSION The unique micropore-confinement effect and excellent adsorption behavior make NC ZIF-8 1000C-800A an efficient adsorbent for furfural in the furfural–acetic acid system. © 2023 Society of Chemical Industry (SCI).
研究领域:
化学工程
·
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Energy & Environmental Materials
·
2024
·
IF 13
Yongbin Liu,Yating Xu,Jinghui Gao,Jingzhe Xu,Ming Wu,Zhengwei Liu,Yilong Wang,Xiaojie Lou,Lisheng Zhong
High-temperature performance of energy storage dielectric polymers is desired for many electronics and electrical applications, but the trade-off between energy density and temperature stability remains fundamentally challenging. Here, we report a general material design strategy to enhance energy storage performance at high temperatures by crosslinking a polar polymer and a high glass-transition temperature polymer as a crosslinked binary blend. Such crosslinked binary polymers display a temperature-insensitive and high energy density behavior of about 6.2 ~ 8.5 J cm −3 up to 110 °C, showing a significant enhancement in thermal resistant properties and consequently outperforming most of the other ferroelectric polymers. Further microstructural investigations reveal that the improved thermal stability stems from the confinement effect on conformational motion of the crosslinking network, which is evidenced by the increased rigid amorphous fraction and steady intermolecular distance of amorphous regions from temperature-dependent X-ray diffraction results. Our findings provide a general and straightforward strategy to attain temperature-stable, high-energy-density polymer-based dielectrics for energy storage capacitors.
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
危险品化学品经营许可证（带存储）