查找使用阿拉丁产品的科研文献

A simple sensing platform based on a 1T@2H-MoS2/cMWCNTs composite modified electrode for ultrasensitive detection of illegal Sudan I dye in food samples

Qiaoling Wu,Chun Ji,Lingli Zhang,Qili Shi,Yuangen Wu,Han Tao

The work presented here describes a highly sensitive and simple electrochemical sensor for the detection of Sudan I dye based on a nanocomposite made of MoS2 heterogeneous nanosheets (1T@2H-MoS2) and carboxylated carbon nanotubes (cMWCNTs) (1T@2H-MoS2/cMWCNTs). XPS results indicate that the content of 1T phase MoS2 was estimated to be 72% in 1T@2H-MoS2. Electron microscopy results show that the tubular cMWCNTs are uniformly interwoven in MoS2 nanosheets to form a three-dimensional network structure. Due to the synergistic electrocatalytic ability and high electroactive surface area, the 1T@2H-MoS2/cMWCNTs modified electrode demonstrated excellent analytical performance for Sudan I, including simple operation, good stability and a wide linear range from 5.00 × 10−9 to 2.00 × 10−6 mol L−1 and 2.00 × 10−6 to 1.00 × 10−4 mol L−1 with an ultra-low detection limit of 1.56 × 10−9 mol L−1. The recoveries of Sudan I from spiked real samples (chilli powder and ketchup) were in the range of 95.60% to 106.10% with low RSD (<5%), indicating that the 1T@2H-MoS2/cMWCNTs modified electrode is a promising tool for the analysis of illegal Sudan I in food samples.

A volatile microemulsion method of preparing water-soluble photo-absorbers for 3D printing of high-resolution, high-water-content hydrogel structures

Xiangnan He,Jianxiang Cheng,Zechu Sun,Haitao Ye,Qingjiang Liu,Biao Zhang,Qi Ge

Digital light processing (DLP)-based three-dimensional (3D) printing is an ideal tool to manufacture hydrogel structures in complex 3D forms. Using DLP to print hydrogel structures with high resolution requires the addition of water-soluble photo-absorbers to absorb excess light and confine photopolymerization to the desired area. However, the current photo-absorbers for hydrogel printing are neither efficient to absorb the excess light nor water-soluble. Herein, we report a volatile microemulsion template method that converts a wide range of commercial non-water-soluble photo-absorbers including Sudan orange G, quercetin, and many others to water-soluble nanoparticles with solubility above 1.0 g mL−1. After using these water-soluble photo-absorber nanoparticles, the highest lateral and vertical resolutions of printing high-water-content (70–80 wt%) hydrogels can be improved to 5 μm and 20 μm, respectively. Moreover, the quercetin nanoparticle can be easily washed out so that we achieve colorless and transparent printed hydrogel structures with excellent mechanical deformability and biocompatibility as well as thermally controllable variations on transparency and actuation. The proposed methods pave a new efficient way to develop water-soluble photo-absorbers, which helps to greatly improve the printing resolution of the high-water-content hydrogel structure and would be beneficial to extend the application scope of hydrogels.

Multishape Programming of Shape Memory Polymer Assemblies Fabricated by Vat Photopolymerization-Based 3D Printing and Interfacial Welding

Yongqi Liu,Biru Yang,Chuhan Song,Qian Zhao,Tao Xie,Zizheng Fang,Jingjun Wu

The combination of three-dimensional (3D) printing and shape memory polymers (SMP) enables programmable shape morphing of complex 3D structures, which is commonly termed four-dimensional (4D) printing. The process requirements of vat photopolymerization-based 3D printing impose limitations on the molecular structure design of SMPs, making it challenging to achieve triple- or multiple-shaped memory effects. Herein, we printed SMPs with different Tg values and obtained an SMP assembly through interfacial welding. The welding process is facilitated by the dynamic exchange of hindered urethane bonds at the interface. The resulting SMP assembly exhibits a quadruple shape memory effect, enabling programmable sequential deformation. The advantage of this approach is that the molecular design and the corresponding thermodynamic properties of different welding SMP components can be independently adjusted, enabling a greater range of shape and functional variations in the final 3D SMP assembly.

High efficiency and selective separation of oily wastewater based on superamphiphilic biomass aerogel: Characteristics, mechanisms and application

Bingjie Wang,Yuxin Wang,Tao Tian,Zhishan Bai

The design and development of multifunctional materials to meet the sophisticated requirements of oily wastewater treatment is an urgent need and remains a great challenge. Herein, a superamphiphilic bio-aerogel (PTGA) with honeycomb-like porous structure was synthesized. The directional and reversible control of interfacial wettability can be achieved by simple pre-wetting process and solvent replacement method. Combined with the advantages of structure and wettability, PTGA was proved to be ideal for high-efficient oil-water mixture separation ( J > 1500 L/m 2 ·h, η > 99.8%), oils absorption ( C abs = 17–26 g/g) and dye selective removal (MO: 73.552 mg/g, MB : 45.876 mg/g). Furthermore, based on the newly developed dynamic separation device and excellent mechanical property of PTGA, enhanced separation of oil-water mixture ( J = 3007 L/m 2 ·h) and synergistic removal of co-existing pollutants (MB: 51.274 mg/g) were realized. Mechanism results indicated that the transition of interfacial wetting properties of PTGA was a multi-stage process, while oil/water separation and dye adsorption were two independent processes. Benefit from facile synthesis and unparalleled characteristics, the designed PTGA promise to be reliable and competitive candidates in wastewater remediation.

Synthesis, characterization and properties of novel nonionic hydrocarbon/fluorocarbon hybrid surfactants containing a short fluoroalkyl chain

Yutang Zhou,Yichao Shen,Liangjie Shi,Yong Jin,Shuangquan Lai,Yujia Tang

Preparation of magnetic β-cyclodextrin ionic liquid composite material with different ionic liquid functional group substitution contents and evaluation of adsorption performance for anionic dyes

Yanfei Wu,Zhuanhong Jia,Chunmiao Bo,Xiaojun Dai

In this study, we successfully prepared two magnetic graphene oxide composites, specifically (mGO @ ILs(1)-βCD and mGO @ ILs(2)-βCD), with different ionic liquid functional group substitution contents on the β-cyclodextrin (β-CD). Structural characterization of the composite material was performed using Fourier transform infrared spectroscopy , X-ray diffraction, field emission scanning electron microscopy , specific surface area and pore volume measurements. Comparison of the adsorption performance of the two materials for anionic dyes (lemon yellow (LY), sunset yellow (SY), and ponceau 4R (P4R)) in simulated wastewater. Effect of initial pH value, contact time were studied and discussed in terms of affinity and adsorption efficiency. The adsorption of the anionic azo dye by two adsorbent followed Langmuir adsorption isotherm models and pseudo-second-order kinetics. Noticeably, the maximum adsorption capacity based on the Langmuir model showed that mGO @ ILs(2)-βCD was better than mGO @ ILs(1)-βCD. Additionally, the adsorbent maintains excellent adsorption capacity after five cycles of adsorption-desorption and has remarkable selective separability. The results showed that the high-density substitution content of the ionic liquid functional groups on β-cyclodextrin in mGO @ ILs(2)-βCD is helpful to improve the adsorption capacity and efficiency.

One-pot synthesis of hydroxypropyl-β-cyclodextrin capped fluorescent sulfur quantum dots for highly sensitive and selective recognition of tartrazine

Zeming Huang,Jiehao Lei,Hong Ruan,Yongyang Gong,Guan Wang,Li Zhou

Sulfur quantum dots (SQDs), the rising star in fluorescent nanomaterials, have captured increasing attention due to their unique attributes. However, the development of SQDs with targeted fluorescence response to analyte is still a challenge. Herein, we report a robust fluorescent SQDs material that possess both molecular recognition and fluorescence detection capability by employing hydroxypropyl-β-cyclodextrin (HP-β-CD) as ligand. The prepared SQDs simultaneously display fine aqueous dispersibility, stable and tunable fluorescence, and favorable biocompatibility, which enable them promising for applications in cellular imaging and sensing. Owing to the synergistic effect of inner filter effect (IFE) and host-guest interaction, the SQDs can be utilized as an effective fluorescent probe for tartrazine (TTZ) detection with excellent sensitivity and selectivity. The limit of detection can reach 82 nM with a wide linear range of 0–30 μM. Furthermore, the fluorescent SQDs were successfully utilized to detect TTZ in river water and food samples with satisfactory performance.

Development of magnetic porous carbon nano-fibers for application as adsorbents in the enrichment of trace Sudan dyes in foodstuffs

Peng Li,Dongting Huang,Junsheng Huang,Jingjie Tang,Pingjun Zhang,Fei Meng

A novel kind of magnetic porous carbon nano-fibers (Fe 3 O 4 @P-CNFs) materials was successfully prepared and used as an adsorbent. Based on the above-mentioned adsorbent, a simple and effective magnetic disperse solid-phase extraction (MSPE) method was developed and first utilized to the enrichment and purification of five Sudan dyes (including Sudan I, Sudan II, Sudan III, Sudan IV, and Sudan Red 7B) in foodstuffs for the first time. High-performance liquid chromatography was used to determine the content of the Sudan dyes. The parameters affecting the extraction performance were studied and optimized, including the amount of the adsorbent and inorganic salt, type and the volume of the eluent, pH of the sample solution and extraction time. Under the optimized experimental conditions, the results show that the proposed method has a good linear relationship (r≥ 0.9993). The limits of detection range from 0.88 μg L −1 to 1.27 μg L −1 . The recoveries range from 86.6% to 99.7% with the relative standard deviations ranging from 0.6% to 7.9% in the methodology validation. The above-mentioned results indicate that the proposed method is a sensitive and reliable procedure with good reproducibility for the detection of Sudan dyes residues in foodstuffs.

Simultaneous and rapid screening and determination of twelve azo dyes illegally added into food products by using chemometrics-assisted HPLC-DAD strategy

Ming-Yue Dong,Hai-Long Wu,Wan-Jun Long,Tong Wang,Ru-Qin Yu

Edible colorants, as an essential external condition of food products, can increase people’s appetite. Some businesses have used some cheap and illegal dyes instead of edible colorants to gain benefits. It not only deceives consumers, but also seriously endangers their health. In this work, two chemometric algorithms assisted high-performance liquid chromatography with diode array detection (HPLC-DAD) were proposed for screening and quantifying twelve azo dyes illegally added into different food products. All analytes were successfully eluted within 6.5 min. With the aid of the prominent “second-order advantage” of the chemometric algorithms, the overlapping peaks and unknown interferences were solved. The spiked average recoveries obtained by alternating trilinear decomposition (ATLD) and multivariate curve resolution-alternating least squares (MCR-ALS) were 82.8–111.5% with standard deviation (SD) less than 6.5% and 78.7–122.6% with SD less than 18.7%, respectively. The limits of detection were 0.01–2.56 mg kg −1 and 0.01–2.95 mg kg −1 , respectively. The results indicated that two algorithms had practical value for the simultaneous and rapid screening and determination of azo dyes in food products. Compared with other methods based on HPLC, the proposed method could flexibly handle different interferences, and had the advantages of high efficiency, simple operation and being environmentally friendly.

Confined Channels Induced Coalescence Demulsification and Slippery Interfaces Constructed Fouling Resist-Release for Long-Lasting Oil/Water Separation

Yajie Ding,Bihan Hu,Liwei Zhuang,Jianqiang Wang,Jindan Wu,Fu Liu,Jiping Wang

Superwetting membranes based on steric exclusion and affinity difference have drawn substantial interest for oil/water separation. However, the state-of-the-art membranes fail to literally sort out fouling and permeability decline and so limit their viability for long-term separation. Inspired by Dayu’s philosophy of “draining rather than blocking water”, herein, we achieve a long-lasting and efficient separation for viscous emulsions by designing poly(hydroxyethyl methylacrylate) (PHEMA)- and polydimethylsiloxane (PDMS)-compensated poly(vinylidene fluoride) membranes based on coalescence demulsification via chemical coordination phase separation. The symmetric and torturous microporous structure facilitated oil spatial confining and coalescence demulsification, while the synergistic compensation of PHEMA and PDMS coordinated the fouling resist and release properties, which was confirmed by multichannel confocal laser scanning microscopy. The developed membrane shows an unprecedented permeability half-life (τ) for viscous emulsions (e.g., decamethylcyclopentasiloxane, soybean oil paraffin, n-hexadecane, and isooctane) under cross-flow operation, far more beyond common superwetting membranes under applied bench-scale dead-end filtration. Our technique for designing “nonfouling” membranes opens up opportunities for advancing next-generation membranes for oil/water separation.

Nonionic surfactants based hydrophobic deep eutectic solvents for liquid–liquid microextraction of Sudan dyes in tomato chili sauces

Jia Chen,Xiao Li,Anqi Huang,Wenwen Deng,Yuxiu Xiao

A new type of high-density hydrophobic deep eutectic solvents (DESs) were synthesized with nonionic surfactants as hydrogen bond acceptors and hexafluoroisopropanol (HFIP) as hydrogen bond donor. Brij-35 was selected as the optimal nonionic surfactant for the preparation of Brij-35-HFIP-DES (molar ratio 1:20). A vortex-assisted DES-based liquid–liquid microextraction method was proposed for determination of Sudan dyes in tomato chili sauces. The whole pretreatment process only needs 5 min and 1.1 mL of organic solvent. The method with HPLC-DAD shows high efficiency (enrichment factors 89–176 and extraction rates 61.0–74.6%) and good performance with linearity (R ≥ 0.9997) in 0.04–2 μg g −1 range, detection limits of 0.0045–0.0118 μg g −1 , recoveries of 91.6–104.5% and intra-/inter-day precision below 8.0%. A “DES in water in DES” aggregate microstructure was observed in DES-rich phase. The proposed method is simple, quick, eco-friendly, and suits for the efficient extraction and accurate determination of Sudan dyes in tomato chili sauces.

Liquid–Liquid Mass Transfer Enhancement in Milliscale Packed Beds

Chencan Du,Peicheng Wang,Yunpeng Hu,Jisong Zhang,Guangsheng Luo

The mass transfer of cyclohexanone oxime (CHO) from n-octane (continuous phase) to H2SO4 (dispersed phase) was enhanced in milliscale packed beds under large phase ratios. The holdups of two phases were determined, and the effects of structure and operating parameters on the overall mass transfer coefficient of the organic phase (K0a) were also investigated, including placement mode, surface property, size of particle and bed, flow rate and phase ratio, and CHO concentration. Different flow regimes were found in different placement modes and surface properties. Compared with tubes, packed beds showed 1 order of magnitude increase of K0a. A prediction model for K0a was proposed and showed good agreement with the experimental results. Pressure drop and energy dissipation were further measured to access the mixing efficiency. These results are therefore expected to contribute to the novel process of the caprolactam industry and expand the applications of microflow technology.