查找使用阿拉丁产品的科研文献

High foliar retention tannic acid/Fe3+ functionalized Ti-pillared montmorillonite pesticide formulation with pH-responsibility and high UV stability

Huayao Chen,Jinghui Zhan,Li Man,Hongkai Deng,Hongjun Zhou,Li Hao,Xinhua Zhou

The large losses and UV-light instability of traditional pesticide formulations during spraying lead to low drug utilization and a threat to the environment and human health. In this work, a tannic acid and iron ion functionalized titanium dioxide pillared montmorillonite drug sustained-release system was successfully prepared. Pillared montmorillonite showed good foliar retention after tannin modification to prevent the loss of the drug during spraying. Under the irradiation of UV light, the shielding and absorption of UV light by the montmorillonite sheet, TiO 2 and tannic acid coating greatly enhanced UV stability of the avermectin (AVM). In addition, AVM@Fe-TA-TiPMt also showed pH response release due to the ion exchange and disintegration of the coating. With the disintegration of tannic acid coating and the release of tannic acid molecules, AVM was rapidly released below pH 7. AVM@Fe-TA-TiPMt exhibited enhanced insecticidal effect due to the excellent foliar retention effect and high drug release. The tannic acid-functionalized sustained-release system has achieved high foliar retention, UV stability and pH-responsive release, which is conducive to the efficient utilization of pesticides and provides valuable information for the development of clay-based pesticide formulations in the future.

A Compact UV-LED-Induced Fluorescence With Short Metal Capillary and Low Light Leakage: Application to Noninvasive Glucose Detection

Weicheng Cai,Zhaolin Li,Hui Huang,Xuejing Li,Jian Zhao,Pengbo Liu,Yajun Wu,Mingchang Liu,Jian Wang

Impact of UV irradiation on Chlorella sp. damage and disinfection byproducts formation during subsequent chlorination of algal organic matter

Feilong Dong,Qiufeng Lin,Jing Deng,Tuqiao Zhang,Cong Li,Xuedong Zai

The frequent occurrence of algal blooms in surface water has attracted more and more attention, which caused many water quality problems, including disinfection byproducts (DBPs). Algal organic matter (AOM) including intracellular organic matter (IOM) and extracellular organic matter (EOM), was a well-known precursor to DBPs formation in drinking water. This study evaluated the effect of ultraviolet (UV) irradiation on the cell integrity, IOM release and DBPs formation during subsequent chlorination of Chlorella sp. Results showed the damage rates of algal cells increased to 40.1% after the high UV irradiation of 528 mJ/cm 2 , which contributed to the release of IOM. In addition, UV irradiation was effective in reducing the formation of haloacetic acids (HAAs) both in AOM and IOM, but promoted the formation of nitrogenous DBPs (N-DBPs) from AOM in subsequent chlorination. Furthermore, neutral pH exerted a positive effect on the formation of DBPs. UV irradiation decreased the bromine substitution factor (BSF) value of AOM at a high bromide level. The BSF values increased with increasing of the concentration of bromide. Moreover, more amino acids and low molecular weight precursors were produced after UV irradiation in filtered supernatant, which contributed to the formation of N-DBPs with algal chlorination. Overall, this information demonstrated pre-oxidation of UV irradiation could be used to treat the algal-rich drinking water.

Facile and Effective Fabrication of Highly UV-Resistant Silk Fabrics with Excellent Laundering Durability and Thermal and Chemical Stabilities

Huiyu Yang,Zhenwei Yu,Ke Li,Lang Jiang,Xin Liu,Bo Deng,Fengxiang Chen,Weilin Xu

As the most favored high-quality biopolymer, silk fiber is widely used in the textile and medical industries owing to its impressive mechanical properties, wear comfort properties, and biocompatibility. However, its photoinstability, chemical instability, and thermal instability seriously hinder its utilization in luxurious fashionable apparels. Therefore, we herein report the preparation of an ultrathin and uniform TiO2–Al2O3 cloth with a thickness of just six in a thousand of fiber on silkworm silk fiber via atomic layer deposition. In this ultrathin composite cloth, the outer TiO2 layer acts as a sacrificial ultraviolet (UV) absorbent to dissipate large amounts of UV energy. Free radicals and electrons generated by the TiO2 layer are effectively blocked outside the surface of the bulk silk fiber by the inner insulating Al2O3 layer. The excellent UV-resistance of the modified silk fiber was confirmed by a lack of fade in the silk fabric after exposure to UV light for 60 min (equal to continuous exposure to strong sunlight for 3285 days). Compared with silk fiber, the tenacity of the prepared SF-200Al2O3–800TiO2 increased by 18.9% even after sunlight exposure. In addition, both the chemical and thermal stabilities of the modified silk fiber were improved. This technology is expected to have potential applications in various fields, such as high-end fabric development and smart materials, and will further guide material design for future innovations in functional fibers and devices.

UV–vis sensor array combining with chemometric methods for quantitative analysis of binary dipeptide mixture (Gly-Gly/Ala-Gln)

Lijuan Huang,Xin Zhang,Zhuoyong Zhang

Many endogenous peptides are circulating in bodily fluids at micromole level, and accurate analysis of endogenous peptides at such low level is important. In this study, we presented an extensible, facile and sensitive sensor array based on UV–Vis spectroscopy of the AuNPs combined with chemometric methods for quantitative analysis of binary peptide mixture (Gly-Gly/Ala-Gln) using UV–Vis spectroscopy. High concentration arginine (Arg) and Cr 3+ can induce aggregation of the AuNPs and DNA-AuNPs. However, the glycylglycine (Gly-Gly) and alanyl-glutamine (Ala-Gln) can prevent the AuNPs from aggregation. We investigated the prevention of AuNPs aggregation by using Gly-Gly and Ala-Gln mixtures and constructed sensor arrays for quantitative analyses of Gly-Gly and Ala-Gln mixtures. The color change of the solution is relevant to the dose of the target, and it can be visualized by the naked eyes or monitored by UV–Vis spectrometry. Results showed that the concentrations of Arg and Cr 3+ are the key factors affecting the sensitivity of the sensor array. Whereas when Gly-Gly and Ala-Gln have to be analyzed simultaneously, concentrations of Arg and Cr 3+ both for Gly-Gly and Ala-Gln are difficult to be optimized. Taking the advantages of multivariate analysis and data fusion, PLS models and backward interval PLS (BiPLS) models were built for fused dataset constructed by UV–Vis data obtained at different concentrations of Arg and Cr 3+ . The best results were obtained from the PLS models. The proposed method can be extended to analysis of other peptides in more complex mixture systems.

Assembly of a UV-LED induced fluorescence system for rapid determination of amiloride in pharmaceutical tablet and human serum

Wanchao Chen,Yinran Xiong,Wenming Wang,Ting Wu,Long Li,Qidi Kang,Yiping Du

A simple and sensitive fluorescence method has been developed for the determination of amiloride (AMI) in pharmaceutical tablet and human serum with a portable, cost-effective, and easy-to-operate fluorescence system. The fluorescence system was assembled with some optical and electronic devices mainly including a 370 nm light-emitting-diode (LED) as light source, a fiber spectrometer and a Raspberry Pi computer. With the system, AMI produced a strong fluorescence emission at 413 nm, and the emitted intensity can maintain good stability with in a wide pH range from 2 to 8. The proposed method was successfully applied to the determinations of AMI in pharmaceutical tablet and human serum. Their detection limits were 1.67 ng mL −1 and 1.43 ng mL −1 respectively, and the recovery was in the range of 94.06–114.0%. Those obtained results proved that the proposed methods combined with the developed fluorescence system could be employed for the routine analysis of amiloride in pharmaceutical tablet and human serum, especially for the fast analysis of them under field conditions.

Hydrogels Self-Assembled from an Azobenzene Building Block: Stability toward UV Irradiation in the Gel and Thin-Film States

Qiuhong Cheng,Yimeng Zhang,Tianxiang Luan,Zhuoer Wang,Ruipeng Tang,Pengyao Xing,Aiyou Hao

Graphical Surprisingly stable : Azobenzene derivatives bearing carboxylic acid units were investigated as hydrogelators. Upon deprotonation/protonation of the carboxylic acids, N -4-azodiphenyl-maleimic acid (ADPMA; see picture) could transform from solution to hydrogel. The ADPMA hydrogel shows typical trans-cis isomerization of the azobenzene unit in solution, yet the hydrogel demonstrates remarkable stability to UV light irradiation in both the bulk gel and thin film states. Azobenzene and its derivatives are widely used as photoresponsive units for the fabrication of photoresponsive smart materials. In this work, two azobenzene derivatives were designed and investigated as hydrogelators, namely N -4-azodiphenyl-maleimic acid (ADPMA) and N -4-azodiphenyl-succinic acid (ADPSA) bearing azobenzene and carboxylic acid segments. In the process of deprotonation/protonation of the carboxylic acids by pH variation, the self-assembly of these two gelators was triggered. ADPMA could transform from solution to hydrogel while the solution of ADPSA formed a precipitate under the same conditions. The solution-gel/precipitate transformation can be repeated by changing the pH. In contrast to the conventional responsiveness to UV-light irradiation for azobenzene-based gels, the ADPMA hydrogel shows typical trans - cis isomerization of the azobenzene unit in solution, yet the hydrogel demonstrates remarkable stability to UV light irradiation in both the bulk gel and thin film states.

Acryloyl-group functionalized graphene for enhancing thermal and mechanical properties of acrylated epoxidized soybean oil UV-curable based coatings

Bowen Dong,Yan Yuan,Jing Luo,Liming Dong,Ren Liu,Xiaoya Liu

Recently, acrylate epoxidized soybean oil (AESO) has become one of the most important industrial, bio-based, UV-curable resins. To reinforce AESO-based UV-curable coatings, acryloyl-group functionalized graphene ( acr -RGO) was successfully prepared and characterized using attenuated total reflection-Fourier transformed infrared spectroscopy, X-ray diffraction, Raman spectroscopy, and thermogravimetric analysis. The AESO/ acr -RGO nanocomposite coatings were fabricated using UV-curing technology to covalently introduce graphene sheets into the AESO matrix. Real-time infrared and ATR-FTIR spectroscopy were used to monitor double-bond conversions and deep curing in the AESO/ acr -RGO coating. Scanning electron microscope images revealed the homogeneous dispersion of acr -RGO in AESO. The thermal and mechanical properties of cured films were evaluated through thermogravimetric analysis, tensile testing, and dynamic mechanical analysis. The results revealed that the introduction of acr -RGO effectively enhanced the mechanical properties and the thermal stability of the host resin AESO. The optimal reinforcing effect was observed at 1.0 wt% acr -RGO loading, under which the tensile strength and storage modulus of the AESO/ acr -RGO nanocomposite improved by 167% and 15%, respectively, compared with those of neat AESO. The initial degradation temperature of the AESO/ acr -RGO nanocomposite was also sharply improved by 61 °C under a loading of 0.5 wt%. Additionally, a slight increase in the glass transition temperature of the AESO/ acr -RGO nanocomposite from 29.6 to 36.1 °C was observed when acr -RGO was incorporated. Furthermore, introducing acr -RGO enhanced the coating properties. By contrast, the composite coating using amino-group functionalized graphene (AESO/ ami -RGO) nanocomposites exhibited poorer mechanical properties and lower thermal stability than its acr -RGO counterpart. The remarkable property reinforcements are thus attributed to the acryloyl-group functionalization of graphene, which improved the compatibility and enhanced the interfacial adhesion of graphene with the AESO matrix.

UV-induced peroxidase-like activity of gold nanoclusters for differentiating pathogenic bacteria and detection of enterotoxin with colorimetric readout

Xiaoxue Xie,Fang Tan,Aiqing Xu,Keqin Deng,Yulong Zeng,Haowen Huang

In this study, gold nanoclusters (AuNCs) in the presence of chitosan were prepared assisted by UV irradiation, which exhibit peroxidase-like property tested with H 2 O 2 /3,3,5,5-tetramethylbenzidine (TMB). The chitosan-AuNCs composite membrane also behaves peroxidase-like property and was characterized by TEM, AFM and SEM, which reveal the formed membrane was homogeneous and the AuNCs are predominantly spherical and well-dispersed without agglomeration in the membrane. A colorimetric assay was established by integrating immunoreactions occurred on the enzyme mimicking AuNC-chitosan composite membrane with varying colored GNPs serving as output signal. Three kinds of bacteria were chosen to serve as model bacteria to evaluate the selectivity of this sensor and Staphylococcus aureus ( S. aureus ), can be easily differentiated from Escherichia coli ( E. coli ) and Bacillus subtilis ( B. subtilis ). Such a colorimetric sensing is an extendable strategy due to the recognition element of probe may be replaceable on the catalytic AuNC-chitosan composite membrane. Staphylococcal enterotoxin B (SE-B) as low as 1.0 × 10 −12 g/mL may be sensitively detected by naked-eye readout. As a practical application, the developed colorimetric strategy was used for rapid onsite screening strategy for S. aureus and detecting SE-B in food samples. This colorimetric strategy provides promising platform for rapid onsite screening pathogenic bacteria and detection of enterotoxin in food safety and environmental monitoring.

Wet scrubber coupled with UV/PMS process for efficient removal of gaseous VOCs: Roles of sulfate and hydroxyl radicals

Ruijie Xie,Jian Ji,Kaiheng Guo,Dongxue Lei,Qingjuan Fan,Dennis Y.C. Leung,Haibao Huang

In this study, wet scrubber coupled with UV/peroxymonosulfate (PMS) was used as a semi-batch process for removing gaseous VOCs. Both ethyl acetate and toluene could be removed efficiently using this coupled process due to the generation of SO 4 − and HO . The mass-transfer coefficients in this coupled process were larger than in wet scrubbing only process. The roles of SO 4 − and HO were investigated, in which SO 4 − acted as the predominant radical for toluene degradation while HO was major for ethyl acetate. This could be further confirmed by simultaneous degradation of ethyl and toluene. Moreover, the reaction solution reused at least four times still showed excellent performance for VOCs removal via re-adding PMS. A possible mechanism on toluene degradation was proposed based on the evolutions of intermediates during the process. This study clarified the roles of non-selective radical (i.e. HO ) and selective radical (i.e. SO 4 − and Cl ) in the removal of a continuous-flow gaseous VOCs by this coupled process.

Fabrication of mechanically robust and UV-resistant aramid fiber-based composite paper by adding nano-TiO2 and nanofibrillated cellulose

Zhao Yongsheng,Dang Wanbin,Lu Zhaoqing,Deng Junbo,Hao Yang,Su Zhiping,Zhang Meiyun

Abstract Aramid fiber-based composite paper is widely used as an engineering material that is often used in outdoor environments. This inevitably cause ultraviolet (UV) damage to aramid fibers. In this work, nanotitanium dioxide (nano-TiO 2 ) was introduced to endow the composite a good UV-resistance while nanofibrillated cellulose (NFC) was used to disperse and deposit TiO 2 nanoparticles onto aramid fibers by physical interaction. Firstly, TiO 2 nanoparticles were treated by (γ-aminopropyl) triethoxysilane to achieve abundant amino-groups (–NH 2 ), which can interact with hydroxyl groups (–OH) of NFC. The results showed that NFC can significantly suppress nano-TiO 2 aggregation and result in a well-defined core–shell structure of TiO 2 nanoparticles uniformly coated onto aramid fibers. Also, the bridge effect of NFC and the reinforcing effect of nano-TiO 2 benefit the mechanical properties the aramid/NFC/TiO 2 composite. The maximum tensile index (~ 16.42 N m/g) and maximum tearing index (~ 9.28 mN m 2 /g) of aramid/NFC/TiO 2 composites increase by ~ 43.4 and ~ 26.1% in comparison with the control sample (~ 11.45 N m/g and ~ 7.36 mN m 2 /g), respectively. Meanwhile, the aramid/NFC/nano-TiO 2 composite achieves a good UV-resistant property because of the dominant light-absorbing ability of well-dispersed TiO 2 nanoparticles. Therefore, our work presents a green and damage-free approach to achieve high-performance aramid fiber composite especially with great UV resistance. Graphical Abstract

UV light-tunable fluorescent inks and polymer hydrogel films based on carbon nanodots and lanthanide for enhancing anti-counterfeiting

Bing Chen,Houpeng Xie,Sui Wang,Zhiyong Guo,Yufang Hu,Hongzhen Xie

Novel water-soluble green fluorescent carbon nanodots (CNs) using methacrylic acid and m -phenylenediamine as precursors were first synthesized using a one-pot hydrothermal method. Red fluorescent lanthanide complexes were prepared using lanthanide ion Eu 3+ and pyridine-2,6-dicarboxylic acid. The optical properties of CNs were characterized using ultraviolet visible (UV) spectra and fluorescence spectra, microscopic morphology was characterized using transmission electron microscopy (TEM) and dynamic light scattering (DLS), and the elemental composition was characterized using Fourier transform-infrared spectroscopy (FT-IR) and X-ray photoelectron spectra (XPS). The fluorescence spectra of the lanthanide complexes were also measured. A simple strategy was developed to prepare UV light-tunable fluorescent inks and polymer hydrogels films based on CNs and lanthanide complexes. The fluorescent inks and polymer hydrogels films could be repeatedly switched between green and red fluorescence. The change of color depended on luminescence of the CNs and the lanthanide complexes under 254 and 365 nm UV light, respectively. The UV light-tunable fluorescent inks and polymer hydrogels films could enhance its anti-counterfeiting function for data and information.