INDUSTRIAL CROPS AND PRODUCTS
·
2021
·
IF 5.645
Xiaoxu Yang,Shiyao Hou,Tingting Chu,Jiazhi Han,Runsen Li,Yanzhu Guo,Yumei Gong,Haiming Li,Zhiwei Wan
Eco-friendly, renewable and green biomass materials are considered as the superior carbon precursors for producing carbon quantum dots (CQDs) in large scale. A major challenge is the limited contents of fluorophores in biomass, which then results in low quantum yields (QYs) and inferior fluorescence emission ability of the obtained CQDs. Herein, lignin with amounts of unsaturated aromatic and carbonyl fluorophores was employed as the carbon precursors to prepare CQDs through a green, facile approach. The magnesium and nitrogen elements were successfully introduced into CQDs with the aim of enhancing their QYs and extending their emission wavelengths. The prepared magnesium, nitrogen-doped CQDs (Mg, N-CQDs) could emit green fluorescence with a quantum yield (QYs) up to 46.38 %. The mechanism of their fluorescence ability was discussed extensively. More interestingly, the Mg, N-CQDs displayed a fluorescence transition between green and yellow color at pH value of 5.4, indicating their potential application as a probe to detect pH values of complicated environments. The findings in this paper would provide a viable strategy to converse lignin biomass waste into high-quality fluorescence nanomaterials.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Jiachang Shen,Maohua Yang,Jianmin Xing
Utilization of an in vitro multi-enzyme catalytic system for the synthesis of fructose from carbon dioxide is a promising approach towards achieving carbon neutrality. However, the lack of effective separation methods for the buffer HEPES (4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid) and the product fructose within the system has hindered the industrialization of in vitro multi-enzyme catalytic synthesis systems. This study aimed to separate and recover HEPES and fructose using nanofiltration technology. We investigated the influence of various parameters, including total solution concentration, solute concentration ratio, pH, and temperature, on the nanofiltration separation performance. Experimental results revealed that increasing the pH to 9.0 significantly decreased the fructose retention rate while maintaining a nearly complete HEPES retention rate. The HEPES-fructose mixed solution was further subjected to diafiltration using a spiral-wound membrane, ultimately yielding fructose and HEPES solutions with purities of 90.22 % and 92.93 %, respectively. Combining separation test results with models such as DSPM-DE, and using characterization methods such as ATR-FTIR and pore size distribution analysis, we observed pore swelling during nanofiltration of the HEPES-fructose solution at pH 9.0. A mechanism for this pore swelling, induced by the dissociation of HEPES under the influence of pH, was proposed: Dissociated HEPES in the solution interacts with the membrane surface at the liquid-membrane interface, causing reversible swelling of the membrane pores at the membrane surface, thereby reducing the retention rate of fructose. The nanofiltration process developed in this study effectively separates HEPES and fructose, enabling resource recycling and cost reduction. Furthermore, this study provides theoretical foundations and practical guidance for the design of nanofiltration separation strategies for similar systems using HEPES as a buffer, holding significant scientific and practical value.
研究领域:
生物工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Catalysis
·
2024
·
IF 11.3
Ting Zhu,Junnan Han,Teng Sun,Jingjie Zhao,Xiaodong Pi,Jun Xu,Kunji Chen
In order to broaden the applications of water splitting for hydrogen production, it is highly desired to develop an ideal catalyst, which can operate in a wide pH range. In this work, we proposed amorphous RuSex nanoparticles (NPs) with a highly disordered structure to introduce abundant surface defects, which contribute to the enhanced HER activity. The optimized RuSe1.5 NPs exhibited the pH-universal activity, which only require an overpotential of 24, 30, and 12 mV to reach a current density of 10 mA cm–2 in 0.5 M H2SO4 (pH = 0), 1 M PBS (pH = 7), and 1 M KOH (pH = 14), respectively. By capitalizing on the synergistic effect between Ru and Se, we have successfully achieved a balance in the strong adsorption of reaction intermediates on Ru sites and significantly improved the performance of HER. This work highlights the crucial role of understanding and harnessing the elemental synergies in the development of optimized HER catalysts and paves the way for the advancement of hydrogen production.
研究领域:
材料科学
·
催化化学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Energy Materials
·
2024
·
IF 5.4
Weihao Wang,Qin Liu,Hong Zhang,Lianmeng Cui,Bomian Zhang,Baokang Niu,Ahmed Eissa Abdelmaoula,Chunhua Han,Lin Xu
The concentrated hydroxide ions (OH–) resulting from the hydrogen evolution reaction gives rise to substantial challenges for the Zn anode/electrolyte interface, including proliferating byproducts and severe dendrite growth. Herein, methyl acetate (MA) additive is proposed to eliminate the crippling OH–, hence manipulating interfacial pH and alleviating accumulation of byproducts. Raman spectra and FTIR analysis elucidate the underlying mechanism of the hydrolysis reaction, which means attacked carbonyl corresponding to the elimination of OH–. In situ pH monitoring verifies availably inhibited OH– concentration with MA additive. From multidimension analysis, the base-catalyzed hydrolysis strategy can significantly protect Zn anode from deterioration during “shelf life” contributing to following superior Zn plating/stripping. Consequently, with MA additive, the pH is stabilized at a lower level of 5.11. Zn plating/stripping achieves a conspicuous cycle life of 2000 h (2.0 mA cm–2 with 2.0 mA h cm–2). Even after “shelf life”, Zn||Zn symmetric cells deliver an impressive cycling stability of 700 h compared to the counterpart of 22 h in ZnSO4. Zn||MnO2/CNT pouch cells with a high mass loading cathode of ∼8 mg cm–2 exhibit a stable lifespan of 100 cycles at 1 C. This work demonstrates a hydrolysis strategy to manipulate interfacial pH and stabilize the interface for the reversible Zn anode.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2019
·
IF 4.784
Zhigang Xiao,Lishuang Wang,Chunyue Lv,Shilong Guo,Xuanxuan Lu,Liwei Tao,Qingsong Duan,Qingyu Yang,Zhigang Luo
Copolymer nanoparticles with pH-responsive properties were prepared by grafting different amounts of 2-(dimethylamine) ethyl methacrylate (DMAEMA) on carboxymethyl maize starch (CMS). The formation of CMS-g-DMAEMA was verified by different techniques and was then used for stabilization of Pickering emulsion at different pH values. The CMS-g-DMAEMA nanoparticles showed pH-responsive properties in Pickering emulsion and the pH-responsivity increased as the amount of DMAEMA increased in the CMS-g-DMAEMA copolymer. The prepared Pickering emulsion underwent emulsion/demulsification transitions at different pH values. The microscopy analysis verified the attachment of CMS-g-DMAEMA on oil-water interface of Pickering emulsion. Pickering emulsion showed different droplets size, contact angle, and Zeta-potential depend on pH value and CMS/DMAEMA ratio in the CMS-g-DMAEMA copolymer. The obtained results revealed that CMS-g-DMAEMA copolymer can be successfully used for preparing and stabilizing of Pickering emulsion at pH 10.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
KEY ENGINEERING MATERIALS
·
2014
·
IF 0
Jian He,Xiao Lei Li,Hui Ming Ji,Qing Pu Wang
ZrO2 wet gel was prepared using zirconium n-butoxide as precursor and 1,2-propylene oxide (PO) as a gelation agent in sol-gel process. Then, tetraethoxysilane (TEOS) was used to strengthen the wet gel in aging process. Finally, the monolithic silica/zirconia aerogel was obtained by supercritical fluid drying. N2 adsorption-desorption method, scanning electron microscope (SEM), and Fourier transform infrared spectroscopy (FTIR) were used to characterize microstructure of the aerogel. The influence of pH of the aging solution on microstructure of silica/zirconia aerogel was studied. The results indicate that the particle size distribution of SiO2/ZrO2 aerogel was more uniform and less aggregate when aging in acid solution. However, the average pore diameter and particle size of SiO2/ZrO2 aerogel was increased by aging in alkaline solution. Aging in alkaline condition was useful for largening the pore size of SiO2/ZrO2 aerogel, and the maximum specific surface area and pore volume were obtained at pH=9. Meanwhile, different reactions were produced between the acid/alkaline solution and the hydroxyl of SiO2/ZrO2 aerogel, and the ester group/amino group was obtained relatively which can modify the network of aerogel and decrease the shrinkage of aerogel during the supercritical fluid drying.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
Polymer Chemistry
·
2013
·Vol. 4
·期 6
·2004-2010
·
IF 5.231
Haibo Wang,Fangming Xu,Dandan Li,Xiangsheng Liu,Qiao Jin,Jian Ji
Efficient delivery systems should be stable in blood circulation, with efficient cellular uptake and rapid drug release in cancer cells. Herein, we synthesized P(2-(methacryloyloxy)-ethyl phosphorylcholine)-b-P(2-methoxy-2-oxoethyl methacrylate) via atom transfer radical polymerization. Doxorubicin (DOX) was linked to the polymer via a pH-responsive hydrazone bond. The polymer prodrug had high DOX content (10.6 wt%) and was able to self-assemble to form core–shell structured micelles. Dynamic light scattering showed that the average size of the micelles was 142.3 nm, which is the ideal size for the enhanced permeability and retention (EPR) effect. The shell of the micelles was composed of phosphorylcholine, which imitated the structure of cell membranes. Studies of intracellular uptake demonstrated that the prodrug micelles were internalized effectively by cancer cells. An in vitro release study indicated that the release of DOX at pH 5.0 was much faster than that at pH 7.4. Moreover, in vitro cytotoxicity showed that this polymer prodrug inhibited the growth of cancer cells remarkably, demonstrating its potential for use as an efficient drug delivery system.
研究领域:
药物递送系统
·
高分子化学
·
肿瘤学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry B
·
2019
·Vol. 7
·期 16
·2626-2633
·
IF 5.047
Nan Pan,Juanrong Qin,Pingping Feng,Zeke Li,Botao Song
Real-time monitoring of wound pH may provide information about the wound healing status and potential bacterial infection. Herein, we integrated the biocompatible color changing substance curcumin into a fibrous material, capable of in situ real-time visually monitoring the wound pH. The results indicate that the curcumin-loaded fibrous mat exhibits an obvious pH-dependent color change from yellow to red brown with a change in pH from 6.0 to 9.0, which can be easily detected by the human naked eye. Moreover, the wound pH conditions can be determined with the aid of a smart phone App after image analysis. Due to their flexibility, the fibrous materials have been further processed into various shapes from 1D to 3D for fitting the irregular wounds. It is believed that smart fibrous materials that can simultaneously real-time monitor the wound pH and repair the wound may change wound management to a convenient and comfortable way.
研究领域:
生物医学工程
·
材料科学
·
医学
✓ 已验证
DOI
PubMed
高影响因子
LUMINESCENCE
·
2024
·Vol. 39
·期 12
·e70055
·
IF 3.2
Jiarui Si,Yikang Liu,Yuanfei Jiang,Yutong Chen,Anmin Chen,Mingxing Jin
The fluorescence quenching behavior of rhodamine 6G (R6G) by graphene oxide (GO) under varying pH conditions was investigated. Utilizing steady-state fluorescence spectroscopy, single-photon counting, and ultrafast time-resolved absorption spectroscopy, we explored the quenching efficiency at pH values of 3, 7, and 11. Our findings reveal that GO effectively quenches R6G fluorescence across all tested pH levels, with the most significant quenching observed at pH 7. This quenching efficiency is attributed to optimal electrostatic interactions and efficient charge transfer between GO and R6G at neutral pH. At pH 3, the quenching efficiency is moderately reduced due to partial protonation of GO, which weakens electrostatic interactions but maintains hydrogen bonding. At pH 11, the quenching efficiency is lowest, likely due to increased electrostatic repulsion and reduced charge transfer resulting from deprotonation of GO. Ultrafast time-resolved absorption spectroscopy further confirmed the dynamic nature of the quenching process, showing distinct differences in relaxation kinetics across the pH spectrum. This study highlights the critical role of pH in modulating the quenching mechanisms of GO and R6G, providing valuable insights for the design of pH-sensitive fluorescence sensing systems.
研究领域:
化学
·
材料科学
·
光谱学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF CHEMICAL PHYSICS
·
2024
·Vol. 161
·期 5
·
IF 3.1
Li Xiaoping,Ma Lijing,Zhou Yu,Lu Xinlong,Jing Li,Jing Dengwei
Regarding the rheological properties of fluids, certain nanoparticles can markedly modify the rheological behavior of low surface tension solutions by interacting with surfactant molecules. In this work, a low surface tension fluid with cetyltrimethylammonium chloride was prepared, and the silica nanoparticles were uniformly dispersed into it by ultrasonic dispersion. By adjusting the size, shape, and concentration of nanoparticles, the fluid behavior can be changed from Newtonian to non-Newtonian with finely tuned viscosity and characterized by a shear-thinning rheological behavior. In addition, this work explored how variations in environmental temperature and solution pH affect the rheological responses of the low surface tension suspension system. The experimental findings revealed that increasing the temperature substantially decreases the system’s viscosity and induces a shear-thickening behavior. It is particularly significant that, under extreme pH conditions (either strongly acidic or alkaline), the viscosity of the nanoparticle suspensions was markedly enhanced at a particle concentration of 10 000 ppm. This interesting result coincided with a notable reduction in the zeta potential and an increase in the average particle size, suggesting an intensified aggregation of particles within the suspension system. A mechanism detailing the interaction between silica nanoparticles and surfactant micelles was proposed. This work indicates that the incorporation of nanoparticles into surfactant solutions offers a powerful approach to modulating fluid rheology across various conditions.
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
FOOD CONTROL
·
2024
·
IF 5.6
Ning Li,Chang Liu,Li Niu,Xu Li,Jacko Feng,Zhiming Liu
In this study, we introduced an innovative method by incorporating 1-butyl-3-methylimidazolium chloride (BmimCl) as a versatile component and fine-tuning the mixture of chitosan, BmimCl, and cyanidin cation (Anth) to create pH-responsive smart films for food freshness. Owing to the dual functionality of BmimCl, it served as a plasticizer as well as enhanced the film’s capacity to display a broader spectrum of visible color changes. The material properties of chitosan films containing BmimCl and Anth at varying concentrations were characterized using FTIR, XRD, mechanical test, TGA, UV-vis and pH sensitivity. The combined results indicate that the chitosan-based pH-responsive smart film possessed excellent mechanical properties, great thermal stability, high light transmission, and a broad pH sensitivity. pH-responsive films were used for real-time freshness monitoring of freshwater shrimps, sterilized milk, and hairtails. Results revealed that BmimCl disrupts the hydrogen bond network of chitosan molecules. The films exhibit a transition from green to red as the food turns from fresh to spoiled, effectively demonstrating their capability to monitor freshness.
研究领域:
食品科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2017
·
IF 7.504
Jinlong Ma,Zhenpeng Hu,Wei Wang,Xinyu Wang,Qiang Wu,Zhi Yuan
A reversible programmed targeting strategy could achieve high tumor accumulation due to its long blood circulation time and high cellular internalization. Here, targeting ligand-modified poly(ethylene glycol) (PEG-ligand), dibutylamines (Bu), and pyrrolidinamines (Py) were introduced on the surface of gold nanoparticles (Au NPs) for reversible shielding/deshielding of the targeting ligands by pH-responsive self-assembly. Hydrophobic interaction and steric repulsion are the main driving forces for the self-assembly/disassembly of Au NPs. The precise self-assembly (pH ≥ 7.2) and disassembly (pH ≤ 6.8) of Au NPs with different ligands could be achieved by fine-tuning the modifying molar ratio of Bu and Py (Rm), which followed the formula Rm = 1/(−0.0013X2 + 0.0323X + 1), in which X is the logarithm of the partition coefficient of the targeting ligand. The assembled/disassembled behavior of Au NPs at pH 7.2 and 6.8 was confirmed by transmission electron microscopy and dynamic light scattering. Enzyme-linked immunosorbent assays and cellular uptake studies showed that the ligands could be buried inside the assembly and exposed when disassembled. More importantly, this process was reversible, which provides the possibility of prolonging blood circulation by shielding ligands associated with the NPs that were effused from tumor tissue.
研究领域:
纳米医学
·
生物材料
·
肿瘤学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）