ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2020
·
IF 7.864
Xiaoxiao Song,Bowen Gan,Saren Qi,Hao Guo,Chuyang Y. Tang,Yong Zhou,Congjie Gao
Transport of water, solutes, and contaminants through a thin film composite (TFC) membrane is governed by the intrinsic structure of its polyamide separation layer. In this work, we systematically characterized the nanoscale polyamide structure of four commercial TFC membranes to reveal the underlying structure–property relationship. For all the membranes, their polyamide layers have an intrinsic thickness in the range of 10–20 nm, which is an order of magnitude smaller than the more frequently reported apparent thickness of the roughness protuberances due to the ubiquitous presence of nanovoids within the rejection layers. Tracer filtration tests confirmed that these nanovoids are well connected to the pores in the substrates via the honeycomb-like opening of the backside of the polyamide layers such that the actual separation takes place at the frontside of the polyamide layer. Compared to SW30HR and BW30, loose membranes XLE and NF90 have thinner intrinsic thickness and greater effective filtration area (e.g., by the creation of secondary roughness features) for their polyamide layers, which correlates well to their significantly higher water permeability and lower salt rejection. With the aid of scanning electron microscopy, transmission electron microscopy, and tracer tests, the current study reveals the presence of nanosized defects in a polyamide film, which is possibly promoted by excessive interfacial degassing. The presence of such defects not only impairs the salt rejection but also has major implications for the removal of pathogens and micropollutants.
研究领域:
材料科学
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环境工程
·
膜技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMOSPHERE
·
2013
·
IF 3.137
Xiaoyan Zhang,Peiyong Guo,Jinxiu Huang,Xiufu Hou
Suspended particles are a natural component of aquatic ecosystems. This study provides a report on the survival, growth and reproduction of common-scale and nanoscale particles of Daphnia magna Straus exposed to five types of particles (i.e. KN (kaolinite), MN (montmorillonite), MNn (nanoscale MN), NP (natural particles), and NPn (nanoscale NP)). The results of the study show that the suspended particles elicited a dose-dependent toxicity in KN, MN and MNn, with the following toxicity pattern: MN > KN > MNn. On the contrary, NP and NPn did not show any harmful effects on the animals. Instead, NP and NPn, especially NPn, contributed to the survivorship of the animals. The animals were able to survive throughout the 21-day period of bioassays, and when the particle concentration reached 600 mg L −1 , they produced many neonates without any addition of food. This experimental results also indicated that the nanoscale particles were less toxic than the common-scale ones, both for MN and NP. Moreover, the results of the 21-day period of bioassays indicated that when the organisms were exposed to particles of different size scales, they showed different selection patterns for allocating resources. This may be due to the generation of different assimilation and digestion patterns.
研究领域:
生态毒理学
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环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2022
·Vol. 29
·期 51
·77344-77358
·
IF 5.19
Ding Baoting,Wang Xiaomeng,Feng Kun,Fu Jingran,Liang Jianru,Zhou Lixiang
Acidic Cr(VI)-containing wastewater has received increasing attention in recent years. Schwertmannite is a suitable adsorbent for its acid resistance and good adsorption ability. However, it shows poor Cr(VI) adsorption performance under acidic conditions. Herein, inspired by the fast neutralization-mineralization process of acid mine drainage (AMD) triggered by alkaline rocks, a novel nano-scaled schwertmannite (Sch-2.7) with high Cr(VI) adsorption capacity was synthesized at constant pH of 2.7 via adding OH − . Compared with common schwertmannite (Sch), appropriate OH − effectively improved mineral yield (the precipitation efficiency of Fe: 96.75% vs. 29.93%), specific surface area (65.1 m 2 /g vs. 18.9 m 2 /g), surface group content, and further Cr(VI) adsorption ability of Sch-2.7. The maximum adsorption capacity was 54.17 (pH = 3), 61.59 (pH = 4), and 66.5 mg/g (pH = 5) for Sch-2.7, whereas only 20.35, 24.51, and 27.17 mg/g for Sch. On average, the former was 2.53 times higher than the latter. Temperature and coexisting ions had little influences on the sorption process of Sch-2.7. The mechanism analysis demonstrated that the Cr(VI) removal by Sch-2.7 was a more thermodynamic favorable process due to abundant reactive-active components on Sch-2.7 for adsorption reaction. This work provided new insight into performance optimization and application potential on Cr(VI) removal of schwertmannite.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2016
·
IF 3.299
Yajie Qian,Jing Zhang,Yalei Zhang,Jiabin Chen,Xuefei Zhou
In this study, a newly emerging oxidant nanoscale calcium peroxide (nCaO 2 ) was synthesized to degrade 2,4-dichlorophenol (2,4-DCP). nCaO 2 was prepared from nanoscale Ca(OH) 2 and H 2 O 2 and confirmed to be less than 150 nm in diameter and 62.23 m 2 · g −1 in specific surface area (SSA). For treating 2,4-DCP, the optimal ratio between Ca(OH) 2 and H 2 O 2 was 1:5. Compared with conventional CaO 2 , nCaO 2 was found to be more efficient for destructing 2,4-DCP. 2,4-DCP was completely degraded in 5 d by nCaO 2 while only 75.0% 2,4-DCP was destructed by conventional CaO 2 . The effects of solution pH and water matrix, including SO 4 2− , HCO 3 − and humic acid (HA) were examined. The reactive species in nCaO 2 system was investigated by photoluminescence (PL) technique and the quenching experiments. Results showed that hydroxyl radical (OH ) was the dominant reactive species for destructing 2,4-DCP. The major oxidation products identified in this study were 2-chlorophenol (2-CP), 4-chlorophenol (4-CP), phenol and benzoquinone (BQ). Our works gave an important insight into the use of nCaO 2 to degrade some organic contaminants which might provide some references for the application of nCaO 2 in chlorophenols contaminated groundwater remediation.
研究领域:
环境科学
·
化学
✓ 已验证
DOI
高影响因子
Nano Energy
·
2024
·
IF 16.8
Xinpeng Luan,Jianbo Li,Shipeng Wu,Guibin Zhang,Hexige Wuliji,Jun Wang
AgCuTe, a p-type medium-temperature thermoelectric material, exhibits great potential as a candidate for converting waste heat into electricity owing to its low thermal conductivity and high thermoelectric performance. However, an unstable phase structure of the material system has hindered the direct observation of various point defects contacting with high performance, despite their predicted possibilities solely based on first-principles calculations. Here, we present the novel observation of Te interstitial atoms together with other point defects, planar defects, and nanoscale atomic aggregation for the first time in the Zn-doped and Te non-stoichiometric AgCuTe system, employing a nanoscale perspective. Through our investigation, we disclose the remarkable coexistence of multidimensional defects, thereby resolving the previously conflicting opinions regarding point defects in this system. The effective control of these defects is crucial for achieving high thermoelectric performance. The Zn Cu point defects regulate carrier concentration and Seebeck coefficient by influencing phase proportion and carrier effective mass. While maintaining the material's inherently large power factor ( PF ), thermal conductivity is effectively reduced through grain refinement and multiscale defect scattering. As a result, the dimensionless thermoelectric figure of merit ( ZT ) of approximately ∼ 1.16 is achieved at 773 K. By altering Te content, a coexistence of diverse defects is introduced, leading to intricate microstructures and phase structures. Consequently, a significant reduction in thermal conductivity is observed. The coexistence of multidimensional defects, as well as their impact on microstructure and thermoelectric transport properties, holds significant implications for the performance control of functional materials.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2016
·
IF 2.822
Lisiqi Xie,Xiao Huang,Xingyu Lin,Bin Su
Miniaturization of the interface between two immiscible electrolyte solutions (ITIES) brings the benefits of enhanced mass transport in comparison with the macroscopic ITIES, similar to those observed with an ultramicroelectrode. In this work, ultrathin free-standing silica isoporous membrane (SIM, 80 nm in thickness) consisting of a high density of perforative channels with a uniform size (2–3 nm in diameter) was used to construct nanoscopic ITIES (nano-ITIES) arrays. Electrochemical characterization of the nano-ITIES array by studying the ion-transfer voltammetric behavior of tetra- n -propylammonium (TPrA + ) suggested the domination of hemispherical molecular diffusion. The effect of trans-membrane resistance on the heterogeneous ion transfer was investigated by varying the supporting electrolyte concentration in both phases, which was found to be negligible due to the ultrathin thickness and high channel density of SIM. In addition, the nano-ITIES array exhibited excellent charge selectivity towards ionizable species due to the overlap of electrical double layer in the ultrasmall silica channels, which could be modulated by the supporting electrolyte concentration, aqueous solution pH and channel surface modification. These findings provide the basis for the nano-ITIES array to be used in ion detection and separation.
研究领域:
材料科学
·
电化学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2019
·
IF 3.375
Li You,Jianxin Cao,Fei Liu
A novel microchannel synthesis route for continuous synthesis of nanosized copper iodide (γ-CuI) using hydrated hydrazine as reducing agent was proposed. We continuously produced γ-CuI spherical nanoparticles in 99% yield and grain size of ca. 44–100 nm. Furthermore, the utilization of hydrated hydrazine was essential in precluding powder plugging the microchannel by self-generated N2. The microreaction process conditions, such as residence time, pH value, temperature, and reactant concentration, had great impact on the crystal phase and grain size. The optical properties analysis showed that red-shift in band age and emission intensity of photoluminescence spectra at 428 nm decreased with decreasing grain size. Moreover, the nanosized spherical γ-CuI exhibits enhanced photocatalytic performance in the photodegradation of methylene blue and methyl orange.
研究领域:
材料科学
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化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2017
·
IF 4.233
Weichang Li,Siqi Liu,Hang Yao,Guoxing Liao,Ziwei Si,Xiangjun Gong,Li Ren,Linge Wang
Polymer vesicles are self-assembled shells of amphiphilic block copolymers (BCPs) that have attracted tremendous interest due to their encapsulation ability and intracellular delivery of therapeutic agents. However, typical processes for the formation of polymer vesicles lead to ensembles of structures with a broad size distribution (from nanometer to micrometer scale) which result in a limitation for efficient cellular uptake. In this study, we present a simple and efficient approach for the fabrication of polymer vesicles with uniform nanoscale dimensions from template formation of electrosprayed particles in a high throughput manner. First, electrospraying was applied to produce micrometer-sized templates of a block copolymer before polymer vesicles were formed from the pre-prepared microparticles via rehydration. Four different biocompatible diblock and triblock copolymers were used to successfully fabricate polymer vesicles with uniform size around 150 nm using this approach. Furthermore, we encapsulate anticancer drug doxorubicin (DOX) within the polymer vesicles via this method. The kinetics of cellular uptake (HeLa cell) and intracellular distribution of DOX-loaded polymer vesicles have been quntified and monitored by flow cytometry and confocal microscopy, respectively. The results show that our new method provides a promising way to fabricate drug-loaded polymer vesicles with controllable nanoscale size for intracellular anticancer drug delivery.
研究领域:
生物材料学
·
药物递送系统
·
肿瘤学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
HEAT AND MASS TRANSFER
·
2021
·Vol. 58
·期 3
·407-417
·
IF 2.464
Zhang Dongxue,Wang Xin,Dong Yantao,Lu Nan,Lan Xiaozheng
Normal alkane tetracosane (C 24 ) as a representative compound containing alkyl chains was loaded into various porous materials to obtain form-stable phase change materials (PCMs). In the pores of controlled porous glasses (CPGs), silica gels (SGs), SBA-15 and KIT-6, C 24 acquired tunable phase transition temperatures. By changing the pore sizes, C 24 displayed regulated temperature windows of around 6 K (via melting) and 10 K (via solid phase transition) in the CPGs, 9 K in the SG pores (via melting) and about 13 K in SBA-15 (via melting). Phase transition temperatures, degree of supercooling and enthalpies of phase transitions exhibited linear dependence on the reverse pore diameter. The transition temperature and enthalpy change also had relevance to pore geometries. The phase sequences and solid structures of C 24 in the pores changed largely. The study provides an insight into thermal properties of nano-sized PCMs.
研究领域:
材料科学
·
热能工程
✓ 已验证
DOI
高影响因子
Materials Express
·
2019
·Vol. 9
·期 6
·675-680
·
IF 1.465
Wang Xiaodong,Yu Mingqing,Li Lei,Fan Xu
Nano-scaled magnesium hydroxide with the special appearance was synthesized by a water precipitation reaction at room temperature. The effects of surfactant, reaction time, reactant concentration on the morphology of nano-scaled magnesium hydroxide were investigated. The nanocomposite
film was prepared by adding nano-sized magnesium hydroxide to polyvinyl alcohol. The mechanical property and flame retardancy of PVA nanocomposites were tested. The results showed that the mechanical properties and flame retardancy of the composite film were improved by adding nano-powders.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2024
·
IF 8.1
Tianran Zhang,Bofeng Shi,Siyu Zhang,Mengfan Song,Jiping Wang,Lixue Zhang,Fang Kang
Due to the development of advanced electronic systems, there is an urgent need for polymer dielectric film capacitors with high breakdown strength ( E b ) and high discharge energy density ( U d ) at elevated temperatures. Herein, an all-organic blend polymer composite is fabricated by blending polyetherimide (PEI) and a trace amount of Poly(vinylidene fluoride) (PVDF), achieving nanoscale phase separation and forming interfaces between PEI and PVDF grain. The real permittivity ( ε r ) and E b of blend composites are simultaneously enhanced after PVDF introduction. It is worth noting that increasing the temperature does not reduce the E b of the PEI/xPVDF blend composite. Our Study shows that optimizing the plasticity and storage modulus of PEI/xPVDF significantly contributes to maintaining E b at elevated temperatures. Additionally, high temperatures enhance the entanglement of molecular chains at the PVDF-PEI interface, further supporting the preservation of E b . Finally, a high E b of 540 MV/m, a high U d of 5.92 J/cm 3 are achieved for the PEI/0.5PVDF blend at 150 °C. This work presents a new approach to enhance the E b of dielectric polymers by optimizing mechanical properties at high temperature, which providing a different strategy for enhancing the energy storage performance.
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
INORGANIC CHEMISTRY COMMUNICATIONS
·
2019
·
IF 1.795
Peng Wang,Qi Sun,Yujiao Zhang,Jun Cao
The purpose of this study was to synthesize nano-sized zeolite 4A from kaolin obtained from Guizhou New Materials Technology Co., Ltd. The properties of the nano-sized zeolite 4A were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR), 29 Si magic-angle spinning (MAS)-nuclear magnetic resonance (NMR) and 27 Al MAS-NMR, X-ray fluorescence (XRF), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET), and thermogravimetry (TG)-differential thermal analysis (DTA). According to SEM studies, it can be concluded that the nano-sized zeolite 4A has a typical cubic morphology. TEM images validate that the nano-sized zeolite 4A is of 100–150 nm in size. From the selected-area electron diffraction (SAED) patterns, it is confirmed that these nano-sized zeolite 4A particles have a pure body-center-cubic structure. The textural properties of the nano-sized zeolite 4A were studied by nitrogen adsorption technique, and it can be concluded that the BET surface area of the nano-sized zeolite 4A is 25.131 m 2 ·g −1 . In addition, it is found that the Langmuir model is best suited for the adsorption isotherms of methane on nano-sized zeolite 4A. Meanwhile, the methane adsorption analysis confirmed that the maximum adsorption amount of the nano-sized zeolite 4A to methane increases with the increase of adsorption temperature in the temperature range of 288–318 K.
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
危险品化学品经营许可证（带存储）