查找使用阿拉丁产品的科研文献

Construction of Superhydrophobic Surfaces Enhanced by Silanized-CNC-Assisted PVDF/PDMS Microsphere Coating

Coatings based on polyvinylidene fluoride (PVDF) and poly(dimethylsiloxane) (PDMS)-based polymeric microspheres can be easily fabricated via non-solvent-induced phase separation (NIPS) and electrostatic spraying (ES) techniques. Both techniques are promising strategies for constructing superhydrophobic surfaces on various substrates. However, PVDF and PDMS inherently suffer from severe aggregation, which generates oversized particles and inhomogeneous microstructures. Conventionally, costly and environmentally hazardous dispersants are required to alleviate this issue, severely restricting the industrial scalability and practical application of such coatings. In this work, methyltrimethoxysilane-modified cellulose nanocrystals (Si-CNCs) were introduced as a green multifunctional modifier to tackle these issues. The results revealed that as structural building blocks and dispersants, Si-CNCs inhibited polymer aggregation via electrostatic repulsion and steric hindrance, refined the particle size and formed uniform micro/nano hierarchical structures. Increasing Si-CNC loading further improved polymer dispersion and superhydrophobic performance. Coatings fabricated by ES showed better hydrophobicity than those fabricated by NIPS. ES achieved a water contact angle (WCA) of 160–166° and a sliding angle (SA) near 1° on cotton fabric, while NIPS had a WCA of 153.8–158° and an SA of around 2°. Wood and glass substrates also obtained favorable superhydrophobicity, with WCAs above 150° and SAs below 1°. Furthermore, all modified surfaces exhibited excellent abrasion resistance. This work provides a relatively eco-friendly, environmentally sustainable, scalable and substrate-flexible strategy for fabricating high-performance PVDF/PDMS-based superhydrophobic coatings.

3D bacterial culture and minimum inhibitory concentration measurement using limited alginate microsphere space

Xiaoxiang Zhou,Jiarong Liu,Yueran Hua,Yi Jia,Tianyi Zhang,Rui Zhang,Hua Wang,Hongxing Shen,Jinfeng Xu,Min Li

Bacterial resistance is a serious threat to global public health, creating a heavy burden on healthcare systems and patients. Traditional antimicrobial susceptibility testing (AST) is time-consuming, and two-dimensional (2D) culture systems fail to accurately replicate the three-dimensional (3D) microenvironment in which bacteria naturally grow. Moreover, conventional AST method only provide endpoint susceptibility results and cannot continuously monitor drug-bacteria interactions. In this study, we used a microfluidic chip to produce monodisperse alginate hydrogel microspheres, which were then used to isolate and encapsulate single Escherichia coli ( E. coli ) strain for 3D culture and AST. Our results demonstrate that the structure and limited space inside the microspheres provide a microenvironment similar to the natural 3D conditions for bacterial growth. Using this hydrogel microsphere-based 3D culture system, we performed rapid minimum inhibitory concentration (MIC) testing and continuous monitoring of E. coli strain to 3 antibiotics with different action mechanisms. This system enables to offer MIC results within 6 h, much faster than conventional methods (>16 h). We believe that combining microfluidic technology with 3D microsphere confined culture can not only effectively meet the needs of rapid clinical diagnosis and treatment by shortening the time needed for MIC testing, but also capture dynamic bacterial growth and antibiotic interactions, providing more valuable information for studying resistance mechanisms and developing treatment strategies.

Microsphere-Fiber Interpenetrated Superhydrophobic PVDF Microporous Membranes with Improved Waterproof and Breathable Performance

Gaoshuo Jiang,Liqiang Luo,Lu Tan,Jinliang Wang,Shenxiang Zhang,Feng Zhang,Jian Jin

Superhydrophobic membranes with extreme liquid water repellency property are good candidates for waterproof and breathable application. Different from the mostly used strategies through either mixing or postmodifying base membranes with perfluorinated compounds, we report in this work a facile methodology to fabricate superhydrophobic microporous membranes made up of pure poly(vinylidene fluoride) (PVDF) via a high-humidity induced electrospinning process. The superhydrophobic property of the PVDF microporous membrane is contributed by its special microsphere-fiber interpenetrated rough structure. The effective pore size and porosity of the PVDF membranes could be well tuned by simply adjusting the PVDF concentrations in polymer solutions. The membrane with optimized superhydrophobicity and porous structure exhibits improved waterproof and breathable performance with hydrostatic pressure up to 62 kPa, water vapor transmission rate (WVT rate) of 10.6 kg m–2 d–1, and simultaneously outstanding windproof performance with air permeability up to 1.3 mm s–1. Our work represents a rather simple and perfluorinated-free strategy for fabricating superhydrophobic microporous membranes, which matches well with the environmentally friendly requirement from the viewpoint of practical application.

TiO2(B) nanosheets modified Li4Ti5O12 microsphere anode for high-rate lithium-ion batteries

Suyang Lu,Yunfan Shang,Wei Zheng,Yushuo Huang,Rui Wang,Wenwen Zeng,Haoran Zhan,Ye Yang,Jun Mei

With the increasing applications of Lithium-ion batteries in heavy equipment and engineering machinery, the requirements of rate capability are continuously growing. The high-rate performance of Li4Ti5O12 (LTO) needs to be further improved. In this paper, we synthesized LTO microsphere-TiO2(B) nanosheets (LTO-TOB) composite by using a solvothermal method and subsequent calcination. LTO-TOB composite combines the merits of TiO2(B) and LTO, resulting in excellent high-rate capability (144.8, 139.3 and 124.4 mAh g−1 at 20 C, 30 C and 50 C) and superior cycling stability (98.9% capability retention after 500 cycles at 5 C). Its excellent electrochemical properties root in the large surface area, high grain-boundary density and pseudocapacitive effect of LTO-TOB. This work reveals that LTO-TOB composite can be a potential anode for high power and energy density lithium-ion batteries.

A diffusion-deposition competition mechanism to tailor silver deposition on aluminum microsphere surfaces

Congqing Yang,Chao Gao,Hu Li,Mingxi Pan,Hui Huang

Silver-coated aluminum powder (Al/Ag) are anticipated to replace Ag powder in industrial production. However, the high activity of Al powder and insufficient understanding of the Ag deposition mechanism pose challenges in effectively controlling the Ag deposition process and morphology, thereby restricting which its applications. In this article, a diffusion-deposition competition mechanism is proposed to explain the growth path of Ag atoms on Al surfaces. This mechanism posits that the growth pathway of Ag atom is governed by the ratio between the surface diffusion rate and the deposition rate (V diffusion /V deposition ). Specifically, when surface diffusion dominates (V diffusion /V deposition ≫1), Ag atoms form a conformal layer, whereas the deposition-controlled (V diffusion /V deposition  < 1 or V diffusion /V deposition ≪1), Ag atoms tend to form chains or clusters. Surface diffusion must be considered in regulation crystal growth process. By understanding this mechanism, Ag/Al particles with excellent electromagnetic wave (EMW) absorption properties (RL min  = −37.8 dB, EAB max  = 4.4 GHz) can be prepared simply by controlling only the experimental conditions that affect the surface diffusion and deposition rates. The insights gained from the proposed mechanism offer new ideas for the preparation of other noble metals or inorganic materials.

Preparation of amino-reserved magnetic chitosan microsphere and its application in adsorbing endotoxin

Yu Yi,Canlin Lai,Yuqi Jiang,Jianfeng Mei,Hong Wang,Guoqing Ying

In this article, we present a novel amino-reserved magnetic chitosan microsphere (ARMCM) prepared from chitosan and Fe 3 O 4 through inverse suspension crosslinking by formaldehyde and epichlorohydrin. The density of ARMCM was 1.47 g/mL, and the amino content was 2.44 mmol/g. The measurements data indicated that the saturation magnetization (σ s ) of ARMCM was 23.2 emu/g. The adsorption results showed that these magnetic chitosan microspheres had good adsorption capacity on endotoxin: the maximum absorption capacity was about 1792.1EU/g in 40 min; the endotoxin adsorption efficiency in the protein solution was close to 80% and what is more, protein adsorption efficiency was only 23.2 and 2.0%, respectively, for acidic and basic proteins. It is expected that this ARMCM will have a feasible and useful application in adsorbing endotoxin from biological products. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Porous CuO microsphere architectures as high-performance cathode materials for aluminum-ion batteries

Xuefeng Zhang,Guohua Zhang,Shuai Wang,Shijie Li,Shuqiang Jiao

Cathode materials with a porous structure are important in the development of aluminum-ion batteries (AIBs). In this research, porous microspheric copper oxide (PM-CuO) composed of stacked numerous bitty nanorods has been synthesized for use in AIBs. Using a simple one-pot hydrothermal process, the-as-synthesized PM-CuO possess a large specific surface area of 21.61 m2 g−1 and a pore volume of 0.179 cm3 g−1. These unique porous features allow PM-CuO to improve the electrochemical performance in the assembled AIBs, which exhibit a high initial charge and discharge capacity of 270.62 and 250.12 mA h g−1 (current density of 50 mA g−1), respectively. In the cycling performance, discharge capacity was observed to remain over 130, 121 and 112 mA h g−1 at current densities of 50, 100 and 200 mA g−1, respectively. The favorable properties of PM-CuO cathode materials are attributed to the unique porous structure and this makes them a promising potential material for use as energy storage devices.

Recyclable, hierarchical hollow photocatalyst TiO2@SiO2 composite microsphere realized by raspberry-like SiO2

Qi Jiang,Jian Huang,Baoguo Ma,Zhengcai Yang,Ting Zhang,Xin Wang

TiO 2 @SiO 2 composite microspheres (TS) were prepared by the deposition of TiO 2 on the raspberry-like SiO 2 @polystyrene microspheres (PSS). The hollow microspheres with hierarchical microtopography possess both improved photocatalytic activity and stabilized TiO 2 particle structure. The results of energy dispersion spectrum (EDS) mapping, X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) showed that after calcination, anatase TiO 2 nanoparticles has formed on the raspberry-like PSS template with preferred deposition among interstitials of the drupelet-like structure. The thermal degradation of the polystyrene (PS) core during calcination led to the hollow microspheres. The photocatalytic experiments indicated that the raspberry-like TiO 2 @SiO 2 composite microspheres (TS1-TS3) had higher photocatalytic efficiency than the smooth ones (TS0), due to the hierarchical and hollow structure. The sample TS2 prepared with a moderate ammonia concentration (3 %) not only had relatively more intact hollow spherical structure, but also enhanced photocatalytic activity. The hollow TiO 2 @SiO 2 composite microspheres (TS3) prepared with 4 % ammonia showed the best photocatalytic efficiency. However, the higher ammonia concentration made the drupelet-like structure unstable and the microspheres tend to disintegrate. The raspberry-like microstructure showed a protective effect on the loaded TiO 2 , which resulted in better recyclability with persistent photocatalytic activity. The hierarchical composite microspheres shed light on the potential effective utilization strategy of nano-photocatalyst.

Pectin/Activated Carbon-Based Porous Microsphere for Pb2+ Adsorption: Characterization and Adsorption Behaviour

Ri-si Wang,Ya Li,Xi-xiang Shuai,Rui-hong Liang,Jun Chen,Cheng-mei Liu

The development of effective heavy metal adsorbents has always been the goal of environmentalists. Pectin/activated carbon microspheres (P/ACs) were prepared through simple gelation without chemical crosslinking and utilized for adsorption of Pb2+. Scanning electron microscopy (SEM) revealed that the addition of activated carbon increased the porosity of the microsphere. Texture profile analysis showed good mechanical strength of P/ACs compared with original pectin microspheres. Kinetic studies found that the adsorption process followed a pseudo-second-order model, and the adsorption rate was controlled by film diffusion. Adsorption isotherms were described well by a Langmuir isotherm model, and the maximum adsorption capacity was estimated to be 279.33 mg/g. The P/ACs with the highest activated carbon (P/AC2:3) maintained a removal rate over 95.5% after 10 adsorption/desorption cycles. SEM-energy-dispersive X-ray spectrum and XPS analysis suggested a potential mechanism of adsorption are ion exchange between Pb2+and Ca2+, electronic adsorption, formation of complexes, and physical adsorption of P/ACs. All the above results indicated the P/ACs may be a good candidate for the adsorption of Pb2+.Keywords:pectin;activated carbon;microsphere;Pb2+;adsorption

Metal organic frameworks derived SnO2 microsphere doped Ag for monitoring low concentration ethanol

Xueling Yuan,Lixia Sun,Junqi Wang,Dankui Liao,Jianhua Sun

Pyrolyze metal-organic frameworks (MOFs) is a promising method to prepare metal oxides with large specific surface and multiple active sites. The obtained metal oxides can be utilized as gas sensors. Noble metal doping is an effective way to improve the gas sensitivity of materials. In this work, SnO 2 are prepared by pyrolyzation of metal organic frameworks and Ag-doped SnO 2 composites are fabricated by AgNO 3 reduction in a water bath at 4 °C. The gas-sensing experiment reveals that the optimum operating temperature of different mass fraction of Ag doped SnO 2 samples is 250 °C which is lower than pure SnO 2 (300 °C). The response of composites (7 wt% Ag–SnO 2 ) is 157 to 10 ppm ethanol, which is about 10 times higher than pure SnO 2 (14). The composites have good selectivity and stability. Such excellent performance is contributed to the increase of the gas adsorption capacity , catalytic active site and oxygen vacancy of the composites caused by the doping of Ag.

Robust phosphoproteome enrichment using monodisperse microsphere–based immobilized titanium (IV) ion affinity chromatography

Zhou Houjiang,Ye Mingliang,Dong Jing,Corradini Eleonora,Cristobal Alba,Heck Albert J R,Zou Hanfa,Mohammed Shabaz

Mass spectrometry (MS)-based proteomics has become the preferred tool for the analysis of protein phosphorylation. To be successful at such an endeavor, there is a requirement for an efficient enrichment of phosphopeptides. This is necessary because of the substoichiometric nature of phosphorylation at a given site and the complexity of the cell. Recently, new alternative materials have emerged that allow excellent and robust enrichment of phosphopeptides. These monodisperse microsphere–based immobilized metal ion affinity chromatography (IMAC) resins incorporate a flexible linker terminated with phosphonate groups that chelate either zirconium or titanium ions. The chelated zirconium or titanium ions bind specifically to phosphopeptides, with an affinity that is similar to that of other widely used metal oxide affinity chromatography materials (typically TiO 2 ). Here we present a detailed protocol for the preparation of monodisperse microsphere–based Ti 4+ -IMAC adsorbents and the subsequent enrichment process. Furthermore, we discuss general pitfalls and crucial steps in the preparation of phosphoproteomics samples before enrichment and, just as importantly, in the subsequent mass spectrometric analysis. Key points such as lysis, preparation of the chromatographic system for analysis and the most appropriate methods for sequencing phosphopeptides are discussed. Bioinformatics analysis specifically relating to site localization is also addressed. Finally, we demonstrate how the protocols provided are appropriate for both single-protein analysis and the screening of entire phosphoproteomes. It takes ∼ 2 weeks to complete the protocol: 1 week to prepare the Ti 4+ -IMAC material, 2 d for sample preparation, 3 d for MS analysis of the enriched sample and 2 d for data analysis.

A novel porous polymeric microsphere for the selective adsorption and isolation of conalbumin

Min Qiao,Meng-Meng Wang,Ming-Li Chen,Jian-Hua Wang

Porous polymeric microspheres , poly(styrene-divinyl benzene, PSDVB)-poly(ethylene glycol monoallyl ether, PEGMAE), termed as PSDVB-PEGMAE, are prepared via double emulsion interfacial polymerization strategy. PSDVB-PEGMAE microspheres exhibit a mean diameter of 2.98 μm, and possess heterogeneous porous structure with a pore volume of 0.354 cm 3  g −1 and a pore size of 34.3 nm. PEGMAE moiety is identified on the external surface of the microspheres, while both PSDVB and PEGMAE moieties are found in the interior pores. The PSDVB-PEGMAE microspheres possess favorable selectivity towards the adsorption of conalbumin (ConA) through hydrogen-bonding and hydrophobic interactions, via surface and inter-pore adsorption. At pH 6, an adsorption capacity of 171.9 mg g −1 is achieved for ConA. The captured ConA may be readily recovered by stripping with a cetane trimethyl ammonium bromide (CTAB) solution (0.1%, m/v). The microspheres are further used for the isolation of ConA from egg white, deriving high purity ConA as demonstrated by SDS-PAGE assay.