MACROMOLECULES
·
2020
·
IF 5.918
Jianquan Xu,Chao Lv,Binyang Du,Xinping Wang,Ophelia K. C. Tsui
We show that the thickness, h0, dependence of the effective viscosity, ηeff(h0), of unentangled random copolymer films of styrene (St) and 4-methoxystyrene (MeOS) supported by silica (SiOx) can be easily tuned by tuning the MeOS concentration, XMeOS, in the copolymer. When XMeOS is increased from 0% to 100%, ηeff(h0) changes steadily from suppressed to enhanced with decreasing film thickness. At XMeOS = 10%, ηeff(h0) displays a nonmonotonic variation. Results obtained by fitting a three-layer model to the ηeff(h0) data show that ηeff(h0) of the XMeOS = 0% film was dominated by the mobility-enhancing effect of the free surface, but as XMeOS increases, the mobility-slowing effect of the substrate surface increases and dominates. The results also show that the propagation distance, lt, of the substrate effect increases with increasing XMeOS and is ∼2.6 to 6 times the radius of gyration of the polymer. We tentatively suggest the long propagation distances to be caused by the long-range van der Waals interactions. Analysis of the van der Waals interfacial potentials of the films supports this interpretation.
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APPLIED SURFACE SCIENCE
·
2018
·
IF 4.439
Pan Li,Chunchao Hou,Xuehua Zhang,Yong Chen,Tao He
The hybrid coupling between inorganic semiconductor and molecular catalyst can provide a promising approach for the construction of highly efficient and selective photocatalytic CO 2 reduction systems. This hybrid system can take full advantage of the strong light harvesting capability of semiconductor and high selectivity of molecular catalyst. The interaction linker bridging the semiconductor and molecular catalyst plays an important role in supplying efficient electron transfer channels. In this study, both CdS with and without ethylenediamine functionalization (i.e., CdS-EF and CdS) have been successfully synthesized and further respectively coupled with tetra(4-carboxyphenyl)porphyrin iron(III) chloride (FeTCPP) for CO 2 photoreduction. It is found that CdS-EF exhibits inferior photocatalytic activity to CdS, while CdS-EF/FeTCPP hybrid photocatalyst shows much higher activity than CdS/FeTCPP. This is because hydrogen bonding exists between the amino groups in CdS-EF and carboxyl groups in FeTCPP, which can act as electron transfer channels from CdS to FeTCPP in the obtained hybrid system.
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Journal of Food Measurement and Characterization
·
2022
·Vol. 16
·期 5
·3501-3511
·
IF 3.006
Chen Hongshuo,Liu Haibin,Cui Chuanjin,Zhang Xuechao,Yang Wei,Zuo Yueming
To effectively cut off the transmission of Brucella to humans through milk, a novel biosensor for detection of Brucella was constructed using cysteamine functionalized nanogold (Cys-Au) and 4-Mercaptobenzoic acid (4-MBA) modified gold electrode as the platform. The morphology of the prepared nanomaterials was characterized by laser particle sizer, XPS and SEM, and the results showed the 4-MBA film was modified on the gold electrode surface, and the diameter of successfully prepared nanogold and Cys-Au are about 55 and 65 nm, respectively. The electrochemical performance of the biosensor was tested in Brucella antigen solution by square wave voltammetry (SWV). The results showed the reproducibility and stability of the biosensor were good, the spiked recovery in milk was in the range of 95.12–105.27%, and the minimum detection limit (S/N = 3) was 5.12 × 10 2 cfu/mL with a linear range from 1.6 × 10 2 to 1.6 × 10 8 cfu/mL. In addition, the minimum detection limit was reduced from 5.12 × 10 2 cfu/mL to 7.0 × 10 1 cfu/mL after processing the SWV data by second-order derivative transformation, which showed Second-order derivative transformation is very helpful to further optimize the performance of the sensor. Compared with the previously reported test methods, the prepared biosensors have a wider linear range and lower limit of detection (LOD). Therefore, the constructed biosensor can be used as a promising tool for the trace detection of Brucella in milk samples.
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Nanoscale Research Letters
·
2018
·Vol. 13
·期 1
·1-9
·
IF 3.125
Liu Mingyue,Gao Zhao,Yu Yanjun,Su Rongxin,Huang Renliang,Qi Wei,He Zhimin
4-Nitrophenol (4-NP) is a priority pollutant in water and is both carcinogenic and genotoxic to humans and wildlife even at very low concentrations. Thus, we herein fabricated a novel molecularly imprinted core-shell nanohybrid as a ratiometric fluorescent sensor for the highly sensitive and selective detection of 4-NP. This sensor was functioned by the transfer of fluorescence resonance energy between photoluminescent carbon dots (CDs) and 4-NP. This sensor was synthesized by linking organosilane-functionalized CDs to silica-coated CdSe quantum dots (CdSe@SiO 2 ) via Si–O bonds. The nanohybrids were further modified by anchoring a molecularly imprinted polymer (MIP) layer on the ratiometric fluorescent sensor through a facile sol–gel polymerization method. The morphology, chemical structure, and optical properties of the resulting molecularly imprinted dual-emission fluorescent probe were characterized by transmission electron microscopy and spectroscopic analysis. The probe was then applied in the detection of 4-NP and exhibited good linearity between 0.051 and 13.7 μg/mL, in addition to a low detection limit of 0.026 μg/mL. Furthermore, the simplicity, reliability, high selectivity, and high sensitivity of the developed sensor demonstrate that the combination of MIPs and ratiometric fluorescence allows the preparation of excellent fluorescent sensors for the detection of trace or ultra-trace analytes.
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PubMed
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2021
·
IF 2.694
Zirui Shu,Sile Shi,Wei Cao,Wensheng Li,Weiping Luo
In this study, the solubility of 4-methylbenzoic acid and terephthalic acid in N-methylformamide, 1,3-dimethyl-2-imidazolidinone, N-methylformanilide, 2-ethyl-1-hexanol, tetrahydrofuran, cyclohexanone, acetophenone, and ethylene glycol diethyl ether was measured using the laser dynamic method under 101.3 kPa at the temperature ranging from 293.65 to 344.35 K. The measured results showed that the solubility of 4-methylbenzoic acid and terephthalic acid increased with the increasing temperature. The solubility of 4-methylbenzoic acid is greater than that of terephthalic acid in the same solvents. The modified Apelblat model and the modified nonrandom two-liquid (NRTL) activity coefficient model were utilized to correlate the solubility of 4-methylbenzoic acid and terephthalic acid in each solvent. The calculated solubility agreed satisfactorily with the measured results with 1.67/1.91% averaged relative deviation (ARD) for terephthalic acid and 0.62/0.69% for 4-methylbenzoic acid in the modified NRTL/Apelblat model, respectively. The result of the Akaike Information Criterion (AIC) analysis showed that the modified Apelblat model was better at correlating the solubility of 4-methylbenzoic acid in 1,3-dimethyl-2-imidazolidinone, ethylene glycol diethyl ether, tetrahydrofuran, acetophenone, N-methylformamide, acetophenone, and terephthalic acid in 1,3-dimethyl-2-imidazolidinone; the modified NRTL model performs better in correlating the solubility of 4-methylbenzoic acid in N-methylformanilide, N-methylformamide, 2-ethyl-1-hexanol, and terephthalic acid in 2-ethyl-1-hexanol, 2-ethyl-1-hexanol, and cyclohexanone N-methylformanilide.
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CHINESE JOURNAL OF POLYMER SCIENCE
·
2020
·Vol. 39
·期 3
·327-336
·
IF 3.154
Shi Zhen,Wang Qi,Li Gui-Fei,Shou Yu-Feng,Zong Hong-Jie,Yan Shi-Feng,Zhang Kun-Xi,Yin Jing-Bo
Self-healing hydrogels with the shear-thinning property are novel injectable materials and are superior to traditional injectable hydrogels. The self-healing hydrogels based on 2-ureido-4[1 H ]-pyrimidinone (UPy) have recently received extensive attention due to their dynamic reversibility of UPy dimerization. However, generally, UPy-based self-healing hydrogels exhibit poor stability, cannot degrade in vivo and can hardly be excreted from the body, which considerably limit their bio-application. Here, using poly (l -glutamic acid) (PLGA) as biodegradable matrix, branching α-hydroxy- ω -amino poly(ethylene oxide) (HAPEO) as bridging molecule to introduce UPy, and ethyl acrylate polyethylene glycol (MAPEG) to introduce double bond, the hydrogel precursors (PMHU) are prepared. A library of the self-healing hydrogels has been achieved with well self-healable and shear-thinning properties. With the increase of MAPEG grafting ratio, the storage modulus of the self-healing hydrogels decreases. The self-healing hydrogels are stable in solution only for 6 h, hard to meet the requirements of tissue regeneration. Consequently, ultraviolet (UV) photo-crosslinking is involved to obtain the dual crosslinking hydrogels with enhanced mechanical properties and stability. When MAPEG grafting ratio is 35.5%, the dual crosslinking hydrogels can maintain the shape in phosphate-buffered saline solution (PBS) for at least 8 days. Loading with adipose-derived stem cell spheroids, the self-healing hydrogels are injected and self-heal to a whole, and then they are crosslinked in situ via UV-irradiation, obtaining the dual crosslinking hydrogels/cell spheroids complex with cell viability of 86.7%±6.0%, which demonstrates excellent injectability, subcutaneous gelatinization, and biocompatibility of hydrogels as cell carriers. The novel PMHU hydrogels crosslinked by quadruple hydrogen bonding and then dual photo-crosslinking of double bond are expected to be applied for minimal invasive surgery or therapies in tissue engineering.
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POLYMERS FOR ADVANCED TECHNOLOGIES
·
2021
·Vol. 32
·期 8
·2908-2915
·
IF 3.665
Shuai Wen,Qiang Liu,Wentian Liang
The linear benzyl chlorine-free poly(4-acetoxystyrene) (PSTO) with low polydispersity ( M w / M n = 1.3) is obtained through anisole quenching of the living polymerization of 4-acetoxystyrene initiated with the St–Cl/SnCl 4 /n-Bu 4 NBr system in CH 2 Cl 2 . The alkylation reaction rate increases with increasing anisole concentration and temperature. With a 4-fold excess of anisole over the initiator, end-chlorine groups are completely capped by anisole in 30 minutes at −15°C through adding extra SnCl 4 prior to the alkylation reaction. In addition, by using 2-methylanisole and 2,6-dimethylanisole as capping agents, it is verified that both para- and ortho-positions substitution of living PSTO cations to the anisole occur during alkylation reactions.
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Materials Today Chemistry
·
2025
·
IF 6.7
Meng Xie,Junyu Chen,Xinjian Cheng,Yufan Wu,Chuanqi Yin
People are placing growing emphasis on sustainable development and environmental protection. Lignin, being the second most abundant biological polymer, holds significant potential for diverse applications. This study modifies and uses lignin as starting material for further applications. The esterification reactions are employed to destroy its hydroxyl groups, making it oil-soluble. Diels-Alder (DA) reactions are used to prepare lignin-based macro-monomers for RAFT polymerization. Meanwhile, this material reacted with the synthesized amine-containing thiolipid compounds with 4-bromo-1,8-naphthalenedicarboxylic anhydride. Then, 1-(2-pyridyl) piperazine replaced the -Br of the naphthalimide to prepare small molecules functioning as both a fluorescence probe and a RAFT reagent. Subsequently, lignin and glycidyl methacrylate (GMA) were incorporated into the polymer via RAFT polymerization. By utilizing polyethylene glycol (PEG) as a binder, the hydroxyl and epoxy groups underwent ring-opening reactions, leading to a lignin-based porous cross-linked network fluorescent film. The fluorescent film exhibits high sensitivity, and specific recognition toward 4-Nitrophenol (4-NP), with a detection limit as low as 0.28 μM. Notably, this research indicates that the film's adsorption capacity for 4-NP reaches 112.4 μg/cm 2 , demonstrating excellent separation performance. The application scope of lignin was enlarged, and it could find more actual usage in the future.
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产品关联
DOI
高影响因子
BIOORGANIC CHEMISTRY
·
2025
·
IF 4.7
Xinqi Xu,Xialian Wang,Lian Xu,Bingmei Su,Juan Lin,Qiaobin Chen
Fe(II)/α-ketoglutarate (α-KG)-dependent isoleucine dioxygenase (IDO) enables selective C-H hydroxylation to produce the antidiabetic agent (2 S , 3 R , 4 S )-4-hydroxyisoleucine ((2 S , 3 R , 4 S )-4-HIL), but its industrial application is limited by insufficient activity and stability and the high cost of α-KG. Here, the IDO from Bacillus thuringiensis was engineered using multiple strategies to generate a mutant MU3 (V146I/S105E/N104P) with increased substrate loading. The specific activity exhibited 15-fold higher (152.0 U/mg) with 15-fold improved catalytic efficiency ( k cat / K m ) for L-isoleucine hydroxylation. The thermostability was enhanced with a 10-fold decrease in thermal inactivation rate at 30 °C. Molecular dynamics simulation revealed that the communication alteration between the loops around the active site and the strengthened substrate binding contributed to the improvement of MU3. The MU3 mediated L-isoleucine hydroxylation was coupled with an optimized whole-cell module integrating L-glutamate oxidase and catalase for α-KG generation from low-cost L-glutamate sodium. By the stepwise whole-cell biocatalytic cascade system, both 500 mM and 750 mM of L-isoleucine could be completely converted into (2 S , 3 R , 4 S )-4-HIL under scaled-up condition. The whole space-time-yield reached 196 g/L/d as the highest record up to date and the cost was decreased compared to the α-KG-supplemented approach. This work provides an efficient, cost-effective and scalable route for (2 S , 3 R , 4 S )-4-HIL synthesis.
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DOI
PubMed
高影响因子
MOLECULES
·
2025
·Vol. 30
·期 7
·1643
·
IF 4.6
Dongmei Gao,Lele Shi,Yuhang Huang,Yingmei Lv,Xuan Yang,Zhenting Du
The thiazole heterocycle is one of the most common moieties found in various drugs. Using 2-aminothiazole as the core structure, the amino group was functionalized with an amide. As a result, 30 trisubstituted 2-amino-4, 5-diarylthiazole derivatives were synthesized, with different substitutions introduced at the C2, C4, and C5 positions. The anti-Candida albicansbiological activities of these synthetic compounds on five kinds ofCandida albicansat different concentrations were detected by the microdilution method. In the first round, four derivatives of 2-amino-4, 5-diarylthiazole exhibited moderate anti-Candida albicansactivity. Among them,4a8was chosen to be subjected to a demethylation process. Thus,5a8was synthesized successfully, giving anti-Candida albicansactivity (MIC80= 9 μM) similar to that of a typical antifungal drug, fluconazole. To understand the mechanism of anti-Candida albicans, molecular docking of the most active5a8against four target proteins of anti-Candida albicans,such as glutamine-fructose-6-phosphoamidamitransferase (GFAT), protein kinase (Yck2), heat-shock protein 90 (Hsp90), and lanosterol 14a-demethylase (CYP51) was carried out. Our research will provide an experimental basis and theoretical guidance for the further design of a new aminothiazole-leading pharmaceutical molecule.
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PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Wenqi Wang,Fan Feng,Wentao Chen,Dongyun Ma,Jinmin Wang
To solve the problems of liquid electrolytes, such as easy leakage, unsafety, and narrow applicable voltage range, a polyacrylamide (PAM) hydrogel electrolyte with high transparency and ionic conductivity has been developed. With addition of a redox indicator, sodium 4-diphenylamine sulfonate (SDAS), a color-changing SDAS@PAM hydrogel electrolyte was obtained. The integration of the PAM hydrogel and SDAS into one layer enables the electrolyte to achieve reversible color changes between green and colorless in addition to the function of transporting ions. An electrochromic device (ECD) based on the resulting color-changing hydrogel electrolyte was constructed with a configuration of FTO/ [email protected] /WO 3 · x H 2 O/FTO, where WO 3 · x H 2 O film was used as the counter electrode. A reversible color change between the superimposed blue-green color to colorless, a large optical modulation (74.2 %), fast responses (6.3 s for coloration and 11.8 s for bleaching) and a good cyclic stability are achieved. Additionally, the synergistic electrochromic effect of SDAS and WO 3 · x H 2 O can significantly reduce the coloration and bleaching voltages of the ECD. Therefore, our strategy of designing ECDs with a color-changing hydrogel electrolyte utilizing a redox indicator paves the way for developing and constructing more energy-efficient smart windows.
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产品关联
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高影响因子
Chemical Engineering and Processing-Process Intensification
·
2022
·
IF 4.264
Kai Zhu,Wenjie Ye,Meng Hu,Yiping Huang,Jingjing Huang,Hanfei Liu,Hao Zhu,Zhenhao Wei,Feng Zhou
4-nitroaniline has been widely used in the production of antioxidants, dyes and pharmaceuticals. A continuous-flow strategy was exploited for the efficient synthesis of 4-nitroaniline through the noncatalytic amination of 4-chloronitrobenzene with aqueous ammonia in a highly controlled and safe manner, in which N-methyl-2-pyrrolidone was selected as the appropriate solvent. Various conditions (reaction temperature, residence time, 4-chloronitrobenzene concentration, molar ratio of ammonia to 4-chloronitrobenzene, presence of base catalyst) were investigated to improve the synthesis of 4-nitroaniline. The Box-Behnken design in response surface methodology was employed for the optimization of reaction conditions, and over 91% yield of 4-nitroaniline could be achieved. Furthermore, a kinetic model was proposed to guide the design and optimization of the synthesis of 4-nitroaniline.
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