Journal of Analysis and Testing
·
2022
·Vol. 6
·期 4
·365-373
·
IF 0
Zhang Tian-Tian,Chen Zi-Han,Shi Guo-Yue,Zhang Min
The abuse of antibiotics has become a global concern, thus it is significant to develop simple antibiotic assays. Herein, a novel type of lanthanide-doped bovine serum albumin (BSA) derived carbon dots (BCDs) dubbed Eu-BCDs has been unveiled for ratiometric fluorescent detection of tetracycline (TC), which was formed from the one-step hydrothermal reaction of Eu 3+ and BSA. Upon challenge with TC, the blue fluorescence of Eu-BCDs at 448 nm was gradually quenched due to the internal filtration effect, while the characteristic red fluorescence of Eu 3+ at 618 nm was significantly enhanced owning to the antenna effect, leading to the ratiometric fluorescent detection of TC with fast response (2 min), a wide linear dynamic range (0–80 μmol/L), and high selectivity and sensitivity (limit of detection (LOD) of 3 nmol/L). Moreover, Eu-BCDs can be successfully applied for the ratiometric fluorescent detection of TC in environmental and biological samples, such as river water, milk, honey and serum. The Eu-BCDs sensing platform would have great application potential in view of its simple preparation, rapid response, high sensitivity and good selectivity.
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ACS Sustainable Chemistry & Engineering
·
2023
·
IF 8.4
Chenguang Jiang,Chunyang Zhou,Wei Tang,Guihua Chen,Su-Na Yin,Wenyuan Xie,Defeng Wu
Cellulose nanofibers are one of the most frequently used fillers for reinforcing hydrogels. The reinforcement, however, is commonly accompanied by the decrease of deformability. Inspired by the armor structured with overall flexible but locally rigid characteristics, we proposed a strategy of constructing chemical networks of bacterial cellulose (BC) in this work to improve the overall mechanical performance of hydrogels. The PAM hydrogels with borax-crosslinked BC nanofibers were prepared. The BC networks are multiscaled, and different levels of structures play different roles. As the flexible networks, the crosslinked BC endows the hydrogels with superior stretchability (7710%) and improves anticutting property as well as crack growth resistance. The crosslinks composed of boronic ester bonds act as “sacrificial bonds”, improving the fatigue resistance to the cyclic tensile with large strain (500%). The mechanical strength of the hydrogels is also significantly enhanced due to the reinforcement role of BC nanofibers. Moreover, the remained sodium ions and borate ions give the hydrogels good conductivity and decreased freezing point. Accordingly, the as-prepared flexible sensor has superior sensitivity (Gauge factor 10.1 for stretching) with satisfactory environmental adaptability. This work proposes an effective strategy of structural regulation for the cellulosic particle-containing hydrogel to improve the overall performance.
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CELLULOSE
·
2023
·Vol. 30
·期 17
·11249-11259
·
IF 5.7
Pan Ying,Liang Qianyong,Du Jia,Zhang Huaiwei,Zhang Dong,Zhao Hongting,Lü Ting,Zhang Yan
Boron and nitrogen co-doped carbon dots (BN-CDs) were synthesized using one-pot hydrothermal carbonization. The synthesized CDs were then combined with alginate and polyethyleneimine to create a multilayered coating on cotton fabric through layer-by-layer (LbL) self-assembly. The CD-containing coating emitted visible blue light under a 365 nm UV lamp. The UV protection, thermal stability, flame retardancy, and wash durability of the CD-treated cotton fabric were subsequently investigated. The ultraviolet protection factors of pure cotton fabric and cotton fabric treated with 12 bilayer CD-containing coating were 6.48 and 64.10, respectively. This indicated that the synthesized CD is an efficient UV absorber. In the TGA test, more char residue was observed at 700 °C for CD coated cotton fabrics under a nitrogen atmosphere. After B, N co-doped CDs were enriched in the PEI/alginate multilayered coating, the peak heat release rate (PHRR) of cotton-CDs-12BL was reduced by 15%, and the T PHRR of cotton-CDs-12BL was improved by 26.4 °C in the microscale combustion calorimeter test. These results indicate that B, N co-doped CDs which possess UV absorption and environmental friendliness, have potential application as a flame retardant on the surface of cotton fiber.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2023
·
IF 8.2
Minzhi Chen,Qi Quan,Zhenping You,Yue Dong,Xiaoyan Zhou
Bioelectronics based on high-performance conductive ionic hydrogels, which can create novel technological interfaces with the human body, have attracted significant interest from both academia and industry. However, it is still a challenge to fabricate hydrogel sensor with integration of good mechanical properties, fast self-healing ability and flexible strain sensitivity below 0 °C. In this paper, we present a moldable, self-healing and adhesive cellulose-based ionic conductive hydrogel with strain-sensitivity, which was prepared by forming dual-crosslinked networks using poly(vinyl alcohol) (PVA) with borax, calcium chloride (CaCl 2 ), zinc chloride (ZnCl 2 ) and 2,2,6,6-tetramethylpiperidine-1-oxyl oxidized cellulose nanofibril (TCNF). The hydrogel exhibited fast self-healing within 10 s, moderate modulus of 5.13 kPa, high elongation rate of 1500 % and excellent adhesion behavior on various substrates. Due to multiple hydrogen bonding and the presence of CaCl 2 and ZnCl 2 , the hydrogel presented a reduced freezing point as low as −41.1 °C, which enabled its application as a low-temperature strain sensor. The proposed hydrogel provides a simple and facile method for fabricating multi-functional hydrogels that can be used as suitable strain sensors for applications such as wearable electronic sensor, soft robotics and electronic skins in a wide temperature range.
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高影响因子
EUROPEAN POLYMER JOURNAL
·
2023
·
IF 6
Haojie Qian,Xiaowen Xu
Fluorescent hydrogels with fluorescent dyes are widely used for anti-counterfeiting encryption. However, developing highly stretchable and remarkable tear-resistant hydrogels with reusable fluorescence for anti-counterfeiting purposes remains challenging. In this study, we fabricated and characterized double network (DN) hydrogels comprising polyvinyl alcohol-borax (PVA-borax) as the first network and poly(methacrylamide- co -polyethylene glycol- co -pyrenylmethyl acrylate) (P(MAM- co -PEGMA- co -PyMA)) as the second network with varying MAM to PEGMA ratios. SEM images showed the hydrogels had 3D porous structures. FT-IR and thermal properties analysis (DSC and TGA) indicated the presence of hydrogen bonds between PVA-borax and P(MAM- co -PEGMA- co -PyMA) without any chemical bonds. The red shift in characteristic absorption bands at 841 and 710 cm −1 further confirmed the presence of π-π* interactions between pyrene moieties. XRD analysis revealed no significant changes in crystalline phase of the hydrogels, which facilitated the formation of a 3D network due to abundant hydrogen bond presence. When the MAM to PEGMA ratio was adjusted to 9:2, the resulting hydrogels exhibited remarkable properties such as ultra-high stretchability (strain over 3300 %), excellent notch-insensitivity, and exceptional tear resistance (tearing energy over 3.25 × 10 5 J/m 2 ). Importantly, the hydrogel's fluorescence intensity could be reversibly changed by alternatively adding Fe 3+ and EDTA-2Na. It could be reused more than 10 times while maintaining a fluorescence intensity of around 80 %, demonstrating its reliability as a versatile hydrogel probe for Fe 3+ detection with “ON-OFF-ON” fluorescence behavior. Furthermore, the hydrogels demonstrated exceptional 2D encryption and decryption capabilities, highlighting their potential applications in information storage and data security. To improve the level of anti-counterfeiting, multiple encryption approaches such as QR codes and ASCII binary codes were rationally designed. Overall, this study successfully developed a universal DN hydrogel platform with ultra-high stretchability and remarkable tear resistance, capable of rapid encoding and decoding of complex information for smart anti-counterfeiting.
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高影响因子
FIRE SAFETY JOURNAL
·
2023
·
IF 3.1
Liang Zhou,Zhicheng Xu,Wenjie Xu,Huiling Jiang,Wenting Xu
A novel approach was used to prepare a new expanded polystyrene (EPS) composite based on calcium sulphate hemihydrate that significantly improves its fire performance. Negative pressure was applied to open cavities between the EPS beads and promoted the absorption of flame retardant slurry. Three fire retardant EPS (FR-EPS) composites with different densities were obtained. Although, a large number of inorganic additives were added, causing the increase in thermal conductivity to 0.043–0.045 W/(m∙K) and water absorption to 4.7–5.8%, the properties remained within an acceptable range. The results of limiting oxygen index (LOI), UL-94 vertical burning and Cone Calorimeter tests revealed that the FR-EPS1 increased LOI from 18.1% to 35.8%, achieved UL94 V-0 grade, decreased PHRR from 384.12 to 81.39 kW/m 2 , and reduced PSPR from 0.159 to 0.014 m 2 /s. With the continued increase of sample density, the measured LOI was further improved, while heat release and smoke production were better suppressed. TG results, and carbon residue after burning indicate that the endothermic dehydration reaction of calcium sulphate dihydrate and the physical barrier effect of the carbonaceous layer contribute to the extraordinary flame retardancy and smoke suppression of the FR-EPS composites.
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ACS Sustainable Chemistry & Engineering
·
2023
·
IF 8.4
Chenguang Jiang,Wenjie Zeng,Xuexue Ding,Defeng Wu
As a member of the dynamic covalent bond family, the boronic ester bond has attracted increasing attention in the fabrication of hydrogels because it can occur in an aqueous system at room temperature. When the hydrogels are applied as a soft sensor, the role of boronic ester bonding is well defined, namely, as a functional unit endowing the system with multistimulus responsiveness. However, this also limits applications of boronic ester bonding in hydrogels. In this work, a heterogeneous hydrogel is developed in which the boronic ester bonding simultaneously acts as structural and responsive units, integrating the actuating and sensing abilities together. The bilayer strategy is applied to give the system network heterogeneity, namely, constructing the physical cross-links of poly(vinyl alcohol) on one side, whereas building dual cross-links, namely, the physical cross-links and the covalent cross-links between carboxymethyl cellulose and poly(vinyl alcohol) together on the other side. Therefore, the as-prepared heterogeneous hydrogels can be used as temperature-triggered and pH-triggered actuators. Moreover, it well retains the strain resistance and temperature resistance effects of the homogeneous hydrogel with boronic ester bonding and can also be used as a flexible sensor monitoring human motions. More application scenarios and working modes for the boronic ester-bonded hydrogels are unlocked.
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高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2023
·
IF 8.2
Fanping Kong,Qian Zhang,Yuan Xie,Jiyue Ding,Hui Zhao,Zihan Zhang,Zequn Ma,Hailin Cong,Zilin Meng
Nanocarrier preparations could effectively improve the utilization rate of pesticides, and reduce pesticide loss. In this study, glyphosate (GLY)-loaded Mg Al layered double hydroxide (GLY@LDH) was synthesized via an in-situ method. Subsequently, GLY@LDH composite samples were prepared using a layer-by-layer self-assembly approach and modified with poly-L-aspartic acid (PASP) and chitosan (CS). XRD, FT-IR, SEM, and Zeta potential characterization confirmed that GLY was successfully loaded in the interlayer of LDHs and PASP/CS were successfully encapsulated on the surface of the composite sample. The release effect in different ionic solutions and soils was studied and analyzed. The release behavior conforms to the Ritger-Peppas kinetic model, and the release mechanism was ion exchange, which was further explored by means of XRD, SEM, and molecular simulation. The results of the anti-scouring experiment and contact angle measurement indicated that the layered self-assembly material enhanced the washing resistance of the material. The practical application effect of the sample was verified through a pot experiment. This study provides new insights into the simple preparation of pesticide-controlled release formulations that reduce leaching losses.
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高影响因子
JOURNAL OF FLUORESCENCE
·
2023
·
IF 2.7
Heng Chendi,He Bowen,Wang Li
In this study, a dual-mode ratiometric fluorometric and colorimetric platform for the determination of nitrite in pickles was proposed by exquisitely employing the fact that non-fluorescent o -Phenylenediamine (OPD) was oxidized by nitrite under acidic conditions to form fluorescent 2,3-diaminophenazine (DAP) (Em = 575), which meanwhile quench the fluorescent nitrogen-doped carbon dots (N-CDs) at 455 nm, the ratio of fluorescence intensity of DAP to N-CDs (F 575 /F 455 ) changed with the increase of nitrite accompanied by visible color changes. Thus, nitrite can be quantitatively detected within a wide linear range (10–500 µM) with a low detection limit of 0.45 µM due to the high quantum yield of 39.7% of N-CDs. In addition, the colour of the N-CDs/OPD system changed from transparent to yellow when the nitrite was introduced, enabling colorimetric and on-site visual detection. The detection limit of the colorimetric method was 3.03 µM with a linear range of 10–500 µM. The proposed ratiometric fluorometric method has pleasant selectivity and good immunity to interference.
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高影响因子
Journal of Materials Chemistry A
·
2021
·Vol. 9
·期 11
·7198-7207
·
IF 12.732
Xiaoyong Yu,Lijing Wang,Xin Wang,Hongzhi Liu,Ziyuan Wang,Yixuan Huang,Guoqiang Shan,Weichao Wang,Lingyan Zhu
Supported metal catalysts are widely used for heterogeneous catalytic processes (e.g., Fenton-like reaction), but the mechanisms of interfacial processes are still ambiguous. Herein, unique nanocarbon based catalysts with Co nanoparticles encapsulated in nitrogen (N)-doped graphene (Co@NG) were prepared by calcination of Co based metal–organic frameworks (MOFs), which showed excellent catalytic performance for peroxymonosulfate (PMS) activation. Comprehensive characterization revealed that there were strong interfacial interactions between Co and the NG layer due to the presence of special nitrogen species, especially graphitic-N. Density functional theory calculations suggested that the strong interfacial interactions provided optimal active sites with low adsorption energy (−1.99 eV) for PMS accumulation, which enabled the generation of highly oxidizing NG–PMS* intermediates as evidenced by in situ Raman microscopy. Electrochemical analyses revealed that the interfacial interactions facilitated surface-to-surface electronic communication across atomic interface-bonding (N–Co). Consequently, phenol was quickly degraded by the NG–PMS* via direct oxidation by an anodic-like nonradical process, and reasonable graphitic-N (G-N) content and pore size are important for this process. Phenol at 1 mM was completely removed within only 12 min by Co@NG-900 (which was prepared at 900 °C), with an apparent rate constant 20 times higher than that of pure NG-900. This work sheds new insights on the critical role of interfacial interactions in nonradical PMS activation.
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高影响因子
FOOD HYDROCOLLOIDS
·
2021
·
IF 9.147
Xin-Sheng Qin,Qun-Yu Gao,Zhi-Gang Luo
In this study, we demonstrated the role of Pickering high internal phase emulsions (HIPEs) stabilized with the whey protein isolate (WPI)/(-)-epigallocatechin-3-gallate (EGCG) covalent conjugates on the storage and GIT passage viability of probiotics powder ( Lactobacillus Plantarum ). At pH 9 value, the WPI-EGCG covalent conjugates by free-radical induction reaction formed hydroxyquinone or hydroxyquinone dimers with better wettability, and digestive enzyme inhibition effect and smaller particle size. Then, the WPI-EGCG covalent conjugates were used to stabilize the O/W type Pickering emulsion. The oil fraction ( ϕ ) addition led to an increase in the droplet size and modulus of Pickering emulsions toward to generate gel-like structure. On the other hand, at a constant ϕ value, the droplet size of these Pickering HIPEs reduced with increasing particle concentration ( c ) from 0.5% to 5%, indicating that high c can stabilize more oil droplets. Encapsulation of Lactobacillus Plantarum powder with the Pickering HIPEs was successful to enhance the viable cell count after 14 days storage and GIT digestion. The protective effect of Pickering emulsions was improved with the addition of the c and/or ϕ value. Therefore, Pickering HIPEs can be applied as a promising carrier for enhancing the viability of probiotic powder during storage and GIT digestion by reason of the high oil phase fraction and the adsorption of the WPI-EGCG covalent conjugates on the droplet interface.
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高影响因子
PEST MANAGEMENT SCIENCE
·
2021
·Vol. 77
·期 7
·3300-3312
·
IF 4.845
Long Chen,Yuanxiong Lin,Hongjun Zhou,Li Hao,Huayao Chen,Xinhua Zhou
BACKGROUND A large amount of pesticides that are not deposited on desired locations due to drift and rolling, endangering the ecological environment and human health. Therefore, it is urgent to develop environmentally friendly and foliar affinity formulations. The design and construction of pesticide nano-delivery system is considered to be an effective way to solve this problem. RESULTS In this research, polyamine-modified zein (AM-zein) was synthesized by incorporating ethylenediamine-terminated polyethyleneimine into zein to improve its stability as a nanocarrier, enhance electrostatic force between the carrier and pesticides and plant foliage. Avermectin (AVM)-loaded nanoparticles, containing a high positive charge, were prepared by the anti-solvent method using AM-zein as carrier. The nanoparticles can be stored for 30 days without any significant change in the particle size and stably dispersed at pH 5–9. Compared to the commercial emulsifiable concentrate (EC), nanoparticles dispersions exhibited better leaf affinity, and the retention of dispersion increased from 7.82 to 13.86 mg/cm 2 . Interestingly, we have discovered for the first time that the ultraviolet (UV) barrier effect of zein increases while prolonging the UV exposure time; 30.47% of the encapsulated AVM remained intact after exposure to UV for 60 min, compared to only 17.13% for the EC. Insecticidal activity of AVM nanoparticles did not improve compared to EC, but they demonstrated significantly lower toxicity against zebrafish. CONCLUSION This research opens up a new idea for improving the stability of zein nanoparticles, providing a novel path to deliver pesticides efficiently and eco-friendly. © 2021 Society of Chemical Industry.
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高影响因子
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