Advanced Powder Materials
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2022
·
IF 0
Hailing Yang,Zhi Wang,Mengyong Sun,Fei Chen,Jun Ji,Sique Chen,Yingying Chen,Deli Ma,Zhenyu Zhang,Baocai Pan,Yulin Wei,Qinggang Li
As a non-toxic copolymer of isobutylene and maleic anhydride, Isobam is successfully used as a dispersant and a gelling agent for fabricating porous Si 3 N 4 ceramics by gel casting. The dispersity and rheological properties of the Si 3 N 4 slurry are influenced by the pH, milling time, and Isobam content which varies from 0.1 wt.% to 0.6 wt.%, and these factors are investigated. The slurry with 40 vol.% solid content and milled for 4 h has a high zeta potential at pH 12 (adjusted by Tetramethyl ammonium hydroxide (TMAH)), which means that the particles are well dispersed. The mechanisms of TMAH are electrostatic repulsion and steric hindrance. The viscosity of the slurry increases with the increase of Isobam content. After pressureless sintering at 1700 °C for 2 h, a uniform unique interlocking microstructure of rod-like β-Si 3 N 4 grains is observed, which may improve the flexural strength of the ceramics by intergranular fracture and particle pullout of β-Si 3 N 4 grains. The density and porosity of the samples fluctuate negligibly with the increase of Isobam content, and the Si 3 N 4 ceramic with 0.1 wt.% Isobam exhibits the highest bending strength of 251.6 MPa among all samples.
研究领域:
材料科学
·
化学工程
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DOI
MOLECULES
·
2024
·Vol. 29
·期 20
·4794
·
IF 4.2
Lin Lin,Ziqi Li,Jian Zhang,Tonghua Ma,Renzhong Wei,Qiang Zhang,Junyou Shi
Phase change energy storage microcapsules were synthesized in situ by using melamine-formaldehyde–urea co-condensation resin (MUF) as wall material, n-octadecane (C18) as core material and styryl-maleic anhydride copolymer (SMA) as emulsifier. Fourier transform infrared spectroscopy, scanning electron microscopy, differential scanning calorimetry and thermogravimetric analysis were used to study the effects of emulsifier type, emulsifier dosage, core–wall ratio and pH on the morphology and thermal properties of microcapsules. The results show that the pH of core material and the ratio of core to wall have a great influence on the performance of microcapsules. SMA emulsifiers and MUF are suitable for the encapsulation of C18. When the pH is 4.5 and the core–wall ratio is 2/1, the latent heat and encapsulation efficiency of phase transition reaches 207.3 J g−1and 84.7%, respectively. The prepared phase-change microcapsules also have good shape stability and thermal stability.
研究领域:
材料科学
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能源存储
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产品关联
DOI
PubMed
高影响因子
Environmental Chemistry and Ecotoxicology
·
2025
·
IF 8.2
Yanhua Wang,Zhengli Tang,Yingnan Liu,Yilin Qian,Shuo Yang,Anqi Wang,Zhibao Dong,Baoshan Xing
Microplastics (MPs) aggregation critically governs their environmental transport, yet interactions with mineral surfaces remain underexplored. In this study, polyethylene (PE) MPs were employed as model particles to prepare both pristine PE and bovine serum albumin (BSA)-coated PE (B-PE). The heterogeneous aggregation of these particles with inorganic minerals (goethite, hematite, pyrite, magnetite) and clay minerals (kaolinite, montmorillonite) was systematically investigated under varying pH conditions (3.0, 6.0, 9.0) and ionic strengths (NaCl 5–300 mmol/L, CaCl 2 1–50 mmol/L). Results demonstrated that positively charged inorganic minerals exhibited significantly stronger heterogeneous aggregation with negatively charged PE, exhibiting aggregation capacities 2.97 times higher than those of negatively charged clay minerals. The introduction of oxygen-containing functional groups such as COOH and OH on the B-PE surface not only enhanced electrostatic attraction but also facilitated ligand exchange and hydrogen bonding, further improving aggregation efficiency. At pH 3.0, removal efficiencies of PE and B-PE for inorganic minerals exceeded 90 %, while aggregation was nearly completely inhibited at pH 9.0. With increasing NaCl concentration, the critical coagulation concentration (CCC) of B-PE decreased by 29.6 %–42.6 % compared to pristine PE. Moreover, Ca 2+ ions exhibited a stronger promoting effect on aggregation via cation bridging than Na + ions. These findings reveal the synergistic regulatory effects of mineral type, protein coating, and environmental factors on microplastic-mineral heterogeneous aggregation, providing a theoretical foundation for predicting the transport and fate of microplastics in complex natural aquatic environments, as well as for developing biomolecule-based sustainable remediation strategies.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
Foods
·
2025
·Vol. 14
·期 15
·2631
·
IF 5.1
Wanyi Sun,Qiuyu Lu,Jiajing Chen,Xinxin Fan,Shengnan Zhan,Wenge Yang,Tao Huang,Fulai Li
This study systematically evaluated the effects of pH (4–10) on the gelation properties, structural characteristics, and in vitro digestion–fermentation behavior of fish gelatin (FG, 6% (w/v)) hydrogels combined with either xanthan gum (XG, 0.07% (w/v)) or κ-carrageenan (κC, 0.07% (w/v)). The results revealed that the gel strength, hardness, and chewiness of the composite gels initially increased (pH 4–6) and subsequently decreased with rising pH levels. This trend correlated with the formation of a dense gel network structure. Furthermore, as pH increased, in vitro digestibility showed a similar pH-dependent trend, with FG–XG demonstrating superior enhancement compared to FG–κC. The addition of XG and κC resulted in increased gas production and a decreased pH during fermentation. Intestinal microbiota analysis revealed that both FG–XG and FG–κC improved the abundances ofProteobacteriaandBacteroidetewhile reducingFirmicutes. Compared to FG–XG and FG, FG–κC promoted higher levels of the generaLachnospiraceaeandBacteroides, suggesting a more favorable impact on intestinal health. These findings provide valuable insights into the pH-responsive functional properties of FG-based hydrogels and their potential applications in designing novel food matrices with enhanced nutritional and probiotic attributes.
研究领域:
食品科学
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生物材料
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营养学
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微生物组学
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功能食品
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产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2021
·
IF 19.503
Jiahuan Luo,Jing Wang,Yao Guo,Jiawei Zhu,Huihui Jin,Zhiwei Zhang,Daojun Zhang,Yongsheng Niu,Shaogang Hou,Jimin Du,Daping He,Yuli Xiong,Lei Chen,Shichun Mu,Yunhui Huang
Hydrogen generation from electrical water splitting has become a greatly increasing requirement for energy systems, however, highly effective and durable electrocatalysts towards universal-pH hydrogen evolution reaction (HER) remain a big challenge. Herein, we design and synthesize ruthenium di-phosphide (RuP 2 ) confined in carbon layers (RuP 2 -C) with a unique yolk-shell structure (RuP 2 -C@RuP 2 -C) from MOF . As expected, it not only exceeds the HER activity of Pt catalysts, with very tiny overpotentials at 10 mA cm −2 (9 and 17 mV in 1.0 M KOH and 0.5 M H 2 SO 4 , individually), but also has high stability. Besides, it also exhibits a low overpotential (40 mV) close to Pt catalysts and high stability in 1.0 M PBS, indicating that RuP 2 -C@RuP 2 -C (RPC@RPC) owns outstanding HER performance at all pH values. Density functional theory (DFT) calculation results further unravel that the P-site on the surface of RPC@RPC possesses low hydrogen adsorption energy, beneficial for boosting the HER activity.
研究领域:
材料科学
·
电化学
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DOI
高影响因子
Journal of Water Process Engineering
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2020
·
IF 3.465
Chang Tian,Yan-Xia Zhao
Polytitanium coagulants have been recently developed and have received wide attention due to both strong coagulation capability and sludge recycling to produce valuable by-products, titanium dioxide (TiO 2 ). This study reports the performance of coagulation with emerging polytitanium salts, polytitanium chloride (PTC) and polytitanium sulfate (PTS), for the treatment of two common cyanobacteria ( Microcystis aeruginosa , MA and Microcystis wesenbergii , MW)-laden surface water, which has been barely reported. Of particular concern is the coagulant dosage and solution pH dependence of polytitanium coagulation, which are the main parameters influencing coagulation efficiency. The influence of basicity (B) of PTC and PTS on coagulation performance was simultaneously included. Results show the optimized B value of 1.5 with coagulant dosage of 30 mg/L and initial solution pH between 7–9 for both PTC and PTS coagulation, wherein obvious advantage of PTC was observed over PTS regardless of MA- or MW-laden surface water treatment. The PTC coagulation could achieve almost complete removal of algae (about 99.0 %) with synergic removal of organic matter with high-efficiency. Both PTC and PTS were more capable at alkaline solution pH conditions for turbidity and algae removal through sweep flocculation, while satisfied removal of the humic acid-representative organic matters was observed at acidic to neutral pH conditions by charge neutralization. Satisfied flocculation zones were determined according to synergic removal of algae, turbidity and organic matters, with most of the satisfied points distributed at solution pH 7–9 conditions. This study will provide theoretical basis and facilitate wide application of the polytitanium coagulation for algae-loaded surface water treatment.
研究领域:
环境工程
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水处理
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胶体与界面化学
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环境化学
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给排水科学与工程
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2012
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IF 3.461
Weizhao Yin,Jinhua Wu,Ping Li,Xiangde Wang,Nengwu Zhu,Pingxiao Wu,Bo Yang
Nitrobenzene (NB) in groundwater has posed significant health risks because of its persistence and high toxicity. In this study, batch experiments were performed to evaluate the effects of initial pH, iron dosage, oxygen and common dissolved anions including Cl − , SO 4 2− , NO 3 − , HCO 3 − , PO 4 3− and humic acid on the NB reduction by zero-valent iron (ZVI). The NB removal increased with the decrease of initial solution pH and a removal efficiency of 88.7% was obtained at an initial pH value of 7.0. The reduction process followed the pseudo-zero-order kinetic model when the iron dosage was 0.5 g L −1 and the corresponding rate constant k 0 was 1.76 mg L −1 h −1 . But it showed a better fit with the pseudo first order kinetics when iron dosage ranged from 1.0 g L −1 to 5.0 g L −1 with the corresponding rate constant k 1 between 0.16 h −1 and 0.76 h −1 . Oxygen inhibited NB reduction due to its competing for electrons from ZVI and the generation of iron oxides. In comparison to the anaerobic system, a 17.1% decrease of NB removal was observed in the air-water system. Improvement of NB removal was observed in the present of Cl − , SO 4 2− and NO 3 − , while bicarbonate would be an inhibitor if its concentration exceeds 50 mg L −1 . The NB reduction was significantly inhibited by PO 4 3− and humic acid since they could form inner-sphere complexes on iron surface. The reaction even ceased as their concentrations reached 8 and 18 mg L −1 , respectively.
研究领域:
环境科学
·
化学
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产品关联
DOI
高影响因子
SEPARATION SCIENCE AND TECHNOLOGY
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2018
·
IF 1.2
Yajuan Li,Yanyang Wu,Kui Chen,Bin Wu,Lijun Ji,Jiawen Zhu
A polymer–salt aqueous two-phase system based on polyethylene glycol and sulfates was applied to explore the partition behavior of spiramycin. Binodal curves were measured by the turbidimetric titration method. The influence of temperature, salt concentration, and pH on the distribution behavior was investigated in detail by determining the partition coefficient and extraction efficiency. As pH and salt concentration increase, the partition coefficients increase accordingly. It was found that pH displays a significant influence on the partition behavior. The partition coefficient and extraction efficiency can reach 42.46 and 97.8%, respectively, at pH 9.0 and 15.80% (w/w) salt concentration.
研究领域:
生物化学
·
制药工程
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产品关联
DOI
高影响因子
RESEARCH ON CHEMICAL INTERMEDIATES
·
2013
·Vol. 40
·期 1
·385-397
·
IF 0.88
Wang Yong,Chen Guihua,Zhang Fumin,Li Liquan
Ni-incorporated SBA-15 magnetic composites were two-stage hydrothermal synthesized from initial strong acidic media through a pH-adjusting method. The structure, morphology, surface area and pore size distribution of the samples were systematically characterized by using XRD, FT-IR, SEM, TEM and N 2 physical adsorption techniques. It was found that, when pH was adjusted to 7, the obtained sample still could exhibit hexagonal mesostructure, very similar to that of the pristine SBA-15 except for a slightly reduced long-range ordering and surface area. However, an increase in the unit cell and wall thickness of the samples suggested the more Ni species were incorporated into the framework of SBA-15. A further increase in pH to 9 produced deterioration of long-range ordering of the sample, possibly resulting from the blocking of some mesopores. Thus, the pH-adjusting method played an important role on the structure of Ni–SBA-15 composites. Measurements taken with increasing applied field revealed the samples having superparamagnetic behaviors. Furthermore, the saturation magnetization values were increased with the more Ni species transforming into magnetic nanoparticles by the increasing pH.
研究领域:
材料科学
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化学工程
·
纳米技术
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产品关联
DOI
高影响因子
NANOTECHNOLOGY
·
2021
·Vol. 32
·期 17
·175604
·
IF 3.874
Fan Liu,Yuan Jiang,HaiBao Shao,Chunlei Wang,Shuhong Xu,Rong Zhang
Precise control of the structure and bonds of doped carbon dots (CDs) is important, so that their fluorescence can be tuned as desired. Up until now, there has been a lack of effective ways to control the bonds of doped CDs. In this article, we show that the fluorescence of B/N-doped carbon dots (B/N-CDs) can be precisely tuned just by controlling their precursors' pH values. The prepared B/N-CDs exhibit two emission bands, including one emission peak at around 450 nm due to the defect state caused by low sp2 hybridization of carbon atoms, as well as another emission peak at around 360 nm caused by the B-N bond. The results for the ratio of the maximum intensity of the two emission peaks above show a linear relationship. Meanwhile, the role of the pH value of the precursors on the luminescence of B/N-CDs is deeply studied. On the one hand, the pH value affects the bonding process of CDs. N-H bonds tend to form at a low pH value, while more competitive B-N bonds exist at much higher pH value, leading to the pH-dependent intensity of the 360 nm emission band. On the other hand, a high pH value causes higher crystallinity, thus suppressing defect-state fluorescence at 450 nm. The dual effects of pH lead to precisely controlled dual-emission intensities as well as ratiometric fluorescence.
研究领域:
材料科学
·
化学
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产品关联
DOI
PubMed
高影响因子
MACROMOLECULES
·
2013
·
IF 5.521
Wei Sun,Shouxue Zhou,Bo You,Limin Wu
This paper is the first to present a facile method of fabricating intelligent surfaces with reversible, precisely controllable, two-way responsive wettability. The ABC-type block copolymers of tert-butyl methacrylate (tBMA), 2-hydroxyethyl methacrylate (HEMA), and 2-(diisopropylamino)ethyl methacrylate (DPAEMA) were synthesized through living radical polymerization mediated by a reversible addition–fragmentation chain transfer (RAFT) process and then grafted onto acyl chloride group-functionalized SiO2 films to produce V-shaped PDPAEMA-b-PHEMA-b-PtBMA brush-grafted SiO2 films. After hydrolysis, V-shaped polymer brushes with two arms of PDPAEMA and PMAA were produced. Because the PMAA and PDPAEMA segments were highly and independently responsive to pH values, the as-obtained films not only exhibited reversible, one-to-one, precisely controllable wettability but also two-way response behavior as pH value increased.
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
JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY
·
2017
·
IF 1.591
Shuang Zhang,Ting Lü,Dongming Qi,Hongting Zhao
Chitosan (CS)-based flocculants, denoted as CS-g-PAM and CS-g-PDBC, were successfully prepared via graft copolymerization of CS with acrylamide (AM) or dimethyl acryloyloxyethyl benzyl ammonium chloride (DBC). The grafting was confirmed by Fourier transform infrared spectroscopy (FTIR) and x-ray photoelectron spectroscopy (XPS). The flocculation performance of CS-g-PAM and CS-g-PDBC, as well as flocculants such as cationic polyacrylamide (CPAM), polyaluminum chloride (PAC), and CS, was evaluated and compared for treating emulsified oil wastewater. It was found that CS-g-PDBC exhibited excellent flocculation performance under both acidic and neutral conditions, while CS showed better flocculation ability under alkaline condition. The flocculation mechanism of CS and CS-g-PDBC was investigated via zeta potential measurements. Results showed that different flocculation mechanisms were involved at various pH levels. As regarding CS, the flocculation mechanism is mainly charge neutralization, patching, and sweep floc under acidic, neutral, and alkaline conditions, respectively, while for CS-g-PDBC, patching was the dominant mechanism under both acidic and neutral conditions.
研究领域:
环境科学
·
材料科学
✓ 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）