CONSTRUCTION AND BUILDING MATERIALS
·
2023
·
IF 7.4
Ning Du,Ruifang Guan,Pengkun Hou
Fluorescent indicators of a wider labeling pH range of 7.0–12.5 were prepared to characterize the pH evolution of the accelerated/natural carbonation of cement and the corrosion of steel bar. Compared with conventional indicators (phenolphthalein, pH range of 8.2–8.5), these indicators indicate multiple pH-induced switches of different fluorescence emissions for the fluorescence resonance energy transfer between donor–acceptor. The results showed that the newly-developed indicators are sensitive and applicable for labeling both natural and accelerated carbonation of cement. Investigations by Fourier Transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and thermogravimetric analysis demonstrated the reliability of these indicators, that is, in the “uncarbonated area” shown by phenolphthalein, carbonization actually occurs as exhibited by fluorescent indicators. Furthermore, electrochemical impedance spectroscopy, as well as dynamic potential polarization studies showed that rusting/corrosion of reinforcing steel started when the pH dropped to 11.5 in the simulation study. This work promoted the contribution of fluorescent indicators in cement carbonation characterization, with a wide pH response.
研究领域:
材料科学
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化学工程
·
土木工程
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DOI
高影响因子
JOURNAL OF FLUORESCENCE
·
2019
·Vol. 29
·期 6
·1423-1429
·
IF 1.913
Meng Xianjiao,Cao Duanlin,Hu Zhiyong,Li Zhichun,Han Xinghua,Ma Wenbing
In this study, a BODIPY-based water-soluble fluorescent chemosensor BBP has been synthesized using BODIPY as the fluorescence group and quinoline as the recognition group. BBP can be used for naked eye detection of pH in complete aqueous solution and it shows high specificity in a wide range of cations. The p Ka value is determined to be 2.94 and the fluorescence intensity is linearly related to pH in the range of 2.4–3.6.
研究领域:
分析化学
·
生物化学
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DOI
PubMed
高影响因子
FOOD RESEARCH INTERNATIONAL
·
2022
·
IF 7.425
Hongxia Tan,Yao Li,Hongyuan Zhou,Ting Guo,Ying Zhou,Yuhao Zhang,Liang Ma
The productions of food, agricultural products and feed involve a variety processing conditions, which can affect the release/binding of zearalenone (ZEN) with macro-components in maize, resulting in the interconversion of hidden ZEN with free ZEN. This interconversion can cause the uncertainties and individual differences in the exposure assessment. To fully overcome this uncertainties of the potential risks for humans and animals, further research regarding the key factors and rule of interconversion is needed. This study was designed to analyze the key factors that can induce the interconversion of hidden ZEN with free ZEN during maize processing. Results showed the conversion of hidden ZEN into free ZEN during thermal and alkaline processing, while it showed the conversion of free ZEN into hidden ZEN during acid processing. Furthermore, the temperature and pH-induced interconversion rules were also applicable to the practical maize processing (tortilla production). During producing tortilla, when the processing conditions of 4% lime, cooking time (60 min) and cooking temperature (100 °C) were set, the tortilla products with the lower hidden ZEN hazard could be obtained. This study presented new insights into the risk assessment of maize products as the conversion between hidden ZEN and free ZEN during processing.
研究领域:
食品安全
·
毒理学
✓ 已验证
DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2023
·
IF 4.4
Xiang Mao,Xia Zhao,Hao Hu,Zequan Li,Wei Xiong,Yujiao Wei,Wei Gao
Work to combat counterfeiting has always been crucial to defending the interests of the public. The usual anti-counterfeiting marks are now fundamental and easy to imitate. Therefore, it is more beneficial to anti-counterfeiting work to develop an anti-counterfeiting mark with more variations to make forgery more difficult. Due to its exceptional stability and fluorescence variability, carbon dots (CDs), a newly developed fluorescent material, offer a wide range of potential applications in anti-counterfeiting. However, there currently needs to be more CD applications in multi-level anti-counterfeiting, and additional issues include high cost and environmental contamination. Therefore, considering the problems of green environmental protection and cost, CDs with excellent green (530 nm) and blue (475 nm, 486 nm) luminescence properties were prepared by a one-step reaction of m-phenylenediamine and glucose. The average fluorescence lifespan is longer than 5 ns, and the optimal quantum yield can reach 37%. Due to the large number of protonated amino groups and surface carboxyl functional groups, the prepared carbon dots exhibit green and blue fluorescence emission modes under acidic and alkaline conditions, respectively. Based on this situation, we produced CD ink and successfully used it for multi-level anti-counterfeiting.
研究领域:
材料科学
·
化学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2019
·
IF 5.107
Gang Yi,Xinfei Fan,Xie Quan,Haiguang Zhang,Shuo Chen,Hongtao Yu
Nanofiltration offers an effective solution in wastewater treatment by size sieving and particularly electrostatic interaction (Donnan effect). However, its separation performance fluctuates with pH changes because both membrane charge and contaminate ionization are sensitive to pH. Therefore, it is significant to fabricate a nanofiltration membrane with steady separation efficiency over a wide pH range. In this study, a novel pH-responsive reduced graphene oxide membrane intercalated by polyacrylic acid-grafted-carbon nanotube (RGO-gCNT membrane) was designed elaborately. Benefited from the pH-responsive property of polyacrylic acid, the pore size of RGO-gCNT membrane can be narrowed in acid solution and enlarged in basic solution. And the pore sizes at pH 3.0 and pH 8.2 are calculated to be about 0.8 and 1.3 nm, respectively. The results of pH influence on phosphate separation show that phosphate rejection rate of the non-responsive RGO-CNT membrane decreases sharply from 91.6% to 11.1% when the pH changes from 8.2 to 3.0. However, the pH-responsive RGO-gCNT membrane can retain 92.7% and 74.2% of the feed phosphates at pH 8.2 and 3.0, respectively. This novel pH-responsive RGO-gCNT membrane provides reliable separation efficiency over a wide pH range and gives new insight to design smart membranes.
研究领域:
环境科学
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材料科学
·
废水处理
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产品关联
DOI
高影响因子
Scientific Reports
·
2017
·Vol. 7
·期 1
·1-9
·
IF 4.259
Xue Ruiyang,Zhang Wang,Sun Peng,Zada Imran,Guo Cuiping,Liu Qinglei,Gu Jiajun,Su Huilan,Zhang Di
pH sensor is an important and practical device with a wide application in environmental protection field and biomedical industries. An efficient way to enhance the practicability of intelligent polymer composed pH sensor is to subtilize the three-dimensional microstructure of the materials, adding measurable features to visualize the output signal. In this work, C. rubi wing scales were combined with pH-responsive smart polymer polymethylacrylic acid (PMAA) through polymerization to achieve a colour-tunable pH sensor with nature gyroid structure. Morphology and reflection characteristics of the novel composites, named G-PMAA, are carefully investigated and compared with the original biotemplate, C. rubi wing scales. The most remarkable property of G-PMAA is a single-value corresponding relationship between pH value and the reflection peak wavelength (λ max ), with a colour distinction degree of 18 nm/pH, ensuring the accuracy and authenticity of the output. The pH sensor reported here is totally reversible, which is able to show the same results after several detection circles. Besides, G-PMAA is proved to be not influenced by the detection angle, which makes it a promising pH sensor with superb sensitivity, stability, and angle-independence.
研究领域:
材料科学
·
生物医学工程
·
化学
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产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2017
·
IF 7.504
Xiaoxia Le,Wei Lu,He Xiao,Li Wang,Chunxin Ma,Jiawei Zhang,Youju Huang,Tao Chen
Poor, nontunable mechanical properties as well as finite shape memory performance pose a barrier to shape memory hydrogels to realize practical applications. Here, a new shape memory hydrogel with tunable mechanical properties and multishape memory effect was presented. Three programmable reversible systems including PBA-diol ester bonds, AAc-Fe3+, and coil–helix transition of agar were applied to memorize temporary shapes and endow the hydrogel with outstanding multishape memory functionalities. Moreover, through changing the cross-linking densities, the mechanical properties of the as-prepared hydrogel can be adjusted.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
POLYMER
·
2017
·
IF 3.684
Fandong Meng,Xiaohui Fu,Yunxia Ni,Jing Sun,Zhibo Li
Smart protein-mimetic materials have received increasing interest for many applications. Here, we reported a facile and efficient approach to prepare a class of dual-responsive copoly( l -glutamate)s by ring-opening polymerization (ROP) and post-modification strategy. Both the oligo(ethylene glycol) (OEG) and glutamic acid residues were incorporated to offer thermal- and pH-responsive property simultaneously. We present a systematic study of the influence of both temperature and pH on the solution properties of the copolypeptides. The copolypeptides show entirely reversible pH-dependent thermal-responsive behaviors with tunable phase transition temperatures. It is demonstrated that the sequence of the polymer units can also influence the solution behavior. The α-helix conformation appears to be the dominant secondary conformation, which shows the pH dependence, but generally irrespective of the temperature. We further verify that the reduced circular dichroism (CD) signal upon heating above the clouding point (CP) is entirely due to the aggregation of the polymer chains. All these features make the obtained polypeptides potential candidates for next generation of smart protein-mimetic materials.
研究领域:
生物材料学
·
高分子化学
·
生物物理学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2020
·
IF 6.182
Lanlan Gan,Qian Su,Zhangbao Chen,Xiaoming Yang
Detections of carcinogen and vitamins are generally recognized to be meaningful, especially for nitrites (NO 2 − ) and ascorbic acid (AA). Here blue-fluorescence carbon dots (CDs) with the quantum yield of 11.83% were successfully synthesized by using folic acid and nicotinic acid, and their surfaces were identified to be abundant in the functional groups of amide, carboxyl and hydroxyl. Importantly, the amide on the surfaces of CDs showed the interactions with the nitrites and formed the complex, thus resulting in their quenched fluorescence. To be specific, the fluorescence intensity of CDs proportionally decreased by adding the increased amounts of NO 2 − from 8 to 800 μM, and achieved the detection of NO 2 − at a detection limit of 21.2 µM. Moreover, further introducing ascorbic acid could prevent CDs with NO 2 − to form the complex and recover their fluorescence, and thus providing the new avenue of assaying AA with the generally favorable linear range of 0.1–800 μM, while its related detection limit was 50 µM. In addition, the synthesized CDs exhibited the satisfactory sensitivity toward different pH values, demonstrating their potential of sensing pH. Consequently, the proposed CDs here may provide a new way of monitoring NO 2 − and AA in the target samples.
研究领域:
分析化学
·
生物医学
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产品关联
DOI
高影响因子
Biomaterials Science
·
2019
·Vol. 7
·期 4
·1643-1651
·
IF 5.251
Zhouxiang Zhao,Chunmei Ding,Yaqin Wang,Hong Tan,Jianshu Li
Traditional antibacterial treatments, such as chlorhexidine (CHX), destroy cariogenic biofilms. However, they exert negative effects in clinical applications, for example, teeth staining, taste disturbance and harm to oral tissue after a long-term exposure. Therefore, biocompatible strategies for efficient antibacterial drug delivery are in high demand. In this study, aimed at dental caries therapy enhancement, we designed a pH-responsive nanocarrier system, capable of releasing CHX in an acidic environment within cariogenic biofilms. Cationic poly(ethylene glycol)-block-poly(2-(((2-aminoethyl)carbamoyl)oxy)ethyl methacrylate) (PEG-b-PAECOEMA) was synthesized first. Modification of PAECOEMA by citraconic anhydride (CA) forms negatively charged PEG-b-PAECOEMA/CA, which could assemble into core–shell polyionic complex micelles (PICMs) when mixed with cationic CHX via electrostatic interactions. PICMs are stable in healthy neutral oral microenvironments with CHX encapsulated in the core and PEG shell exposed. Once in acidic milieu within caries-producing biofilms, they rapidly disassemble and release CHX cargo owing to degradation of citraconic amide groups. Molecular structures of the above copolymers were confirmed using 1H NMR and gel permeation chromatography (GPC) analysis. The pH-dependent degradation rates of citraconic amide in PEG-b-PAECOEMA/CA copolymer were measured by fluorescamine method. Atomic force microscopy (AFM) studies confirmed successful assembly of well-defined spherical PICMs in aqueous solution. The disassembly of PICMs in acidic microenvironment was observed using dynamic light scattering (DLS). PICMs showed an obvious pH-dependent drug release profile when the pH changed from 7.4 to 5.5. More importantly, the micellar system could reduce drug toxicity of CHX and exhibited outstanding antibacterial capability in the biofilm of Streptococcus mutans. Micelles constructed from pH-sensitive PEG-b-PAECOEMA/CA are highly promising for dental caries therapy and provide guidelines for drug-delivery system design in other acidic pathologic systems.
研究领域:
牙科学
·
材料科学
·
药剂学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF POLYMER ANALYSIS AND CHARACTERIZATION
·
2023
·
IF 1.9
Xiaohong Hu,Weiwei Jin,Haitao Zhang,Qinyu Qing,Juan Pang
Visible-light-driven azobenzene had been reported by theoretical calculation, but could not be detected by any characterization method due to unstable cis structure. Herein, copolymerization was applied to solve the problem based on a time-dependent characteristic of macromolecular motion. Therefore, two copolymers, namely, MRAA-PEG20 copolymer and MRAA-NIPAM copolymer, were synthesized with a definite segment ratio. Both copolymers had photosensitive groups, which were confirmed by UV-vis spectra. Furthermore, copolymer concentration had a linear relationship with absorbance value at 425 nm. Firstly, blue light as an excitation source to induce the isomerization of copolymers. At the same time, repeated interval irradiation was used to evaluate the fatigue performance of the copolymer. Consequently, both copolymers could quickly transform to their cis isomers upon irradiation, which could be reversible recovered to their trans isomers in operable recovery time after removing irradiation. However, the MRAA-PEG20 copolymer had an obvious photobleaching phenomenon along with the circle index, which did not exist in the MRAA-NIPAM copolymer. Secondly, the effects of excitation light source on isomerization were investigated. It was found that blue light was the most efficient excitation source for both copolymers though other light could also induce trans-to-cis transition. Thirdly, the influence of light intensity and temperature was respectively studied. With increasing of light intensity, the absorbance ratio before and after irradiation monotonously decreased, the irradiation response time shortened and the recovery response time prolonged. Moreover, higher temperature resulted in a higher absorbance ratio, shorter irradiation response time, and shorter recovery response time. Finally, synthesized copolymers had characteristic of pH indicator with a critical point of pH 5.0.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2017
·
IF 5.401
Jianhua Lü,Yuqin Fu,Dongmei Wang,Changli Lü
Luminescent silver nanoclusters (NCs) decorated with temperature-responsive copolymer P(NIPAm-co-MQ) have been fabricated in aqueous solution as a new fluorescent pH stimuli-responsive functional materials. P(NIPAm-co-MQ) was prepared by a conventional free-radical copolymerization of isopropylacrylamide (NIPAm) as thermo-responsive units and 5-(2-methacryloylethyloxymethyl)-8-quinolinol (MQ) as coordinating groups. The obtained fluorescent Ag NCs with various sizes showed different morphologies from single sphere to chain structure induced by the copolymer ligand. Upon changing the temperature, the fluorescence intensity of the Ag NCs exhibited temperature triggered response simultaneously. The copolymer stabilized Ag NCs as a pH probe exhibited reversible pH-dependent PL properties over the pH range of 3.04–5.25. With the pH decreased, the fluorescence intensity of Ag NCs under a UV lamp decreased and it was almost completely quenched after pH 3.04. Also, the properties of this fluorescence change with pH are reversible.
研究领域:
材料科学
·
纳米技术
·
分析化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）