查找使用阿拉丁产品的科研文献

Robust and adhesive lignin hybrid hydrogel as an ultrasensitive sensor

Huijuan Xiu,Haizhi Zhao,Lei Dai,Jingyu Li,Zhi Wang,Yuxin Cui,Yurou Bai,Xinyi Zheng,Jinbao Li

The fabrication of hydrogel for sensing purposes remains to be a challenge since the hydrogel needs to have both good mechanical strength and adhesiveness. This work reports a robust and adhesive hydrogel mainly constructed with AgNPs@lignin, polyacrylamide (PAM) and sodium alginate (SA). The silver nanoparticles (AgNPs) were in-situ generated via the reaction between lignin and silver ammonia ([Ag(NH 3 ) 2 ] + ). The resultant lignin hybrid hydrogel exhibited a stress, strain and tearing energy up to 0.055 MPa, 1000% and 250 J·m −2 , respectively. Furthermore, the hydrogel adhered to different materials with an adhesion energy of higher than 230 J·m −2 . This hydrogel was demonstrated to be an ideal sensing material since it could detect both large-scale motions and tiny physiological signals including breathing and pulse. The hydrogel also exhibited good antibacterial performance and biocompatibility. This work provides a good example to design a lignin-based high-performance hydrogel material for sensing purposes.

An antibacterial non-woven fabric: preparation, antibacterial and mechanical properties

Yamin Chen,Hui Wang,Yuanhao Yu,Haoliang Ning,Sifan Yuan,Shichao Su,Xiaohui He,Jingpei Xie,Shuge Peng

To improve the antibacterial properties of the non-woven fabric (Tel), the antibacterial Tel composed of chitosan and silver ions composite antibacterial agents (CS-Ag/Tel) was prepared by a facile impregnation method in this work. The morphology, surface composition, microstructure, stability and mechanical properties of the as-prepared antibacterial non-woven fabrics were characterized by FT-IR, SEM, ICP, contact angle and universal testing machine, respectively. The antibacterial performance was evaluated by agar diffusion method and viable bacteria counting method. The results showed that the chitosan-silver ions was successfully impregnated on the surface of the Tel, and endowed the Tel with good stability and antibacterial performance. The ICP test showed that the maximum release concentration of silver in CS-Ag/Tel was 0.142 ppm. The antibacterial tests showed the modified CS-Ag/Tel had an obvious inhibition zone and the antibacterial rate arrived at 96.33%. At the same time, the mechanical properties of the as-prepared CS-Ag/Tel was comparable to the raw Tel. These findings suggested that the as-prepared CS-Ag/Tel had an excellent antibacterial performance, which showed important value in the development and application of the non-woven fabric in the fields of cosmetics and medicine.

Synthesis, fabrication and properties research of CS-mPEG-AN nanocomposite

KangRui Wang,Hong Tang,Hongjie Chen,Xiaorong Huang,Ying Fang,Rongrong Men,Jie Gao,Yue Wang,Yang Wang,ChengHong Huang

Biosynthesis of lactones from diols mediated by an artificial flavin

Zhang Xiaowang,Tan Zhuotao,Li Chaojian,Qi Siyu,Xu Mengjiao,Li Ming,Xiong Wenlong,Zhuang Wei,Liu Dong,Zhu Chenjie,Ying Hanjie

Background Lactones are important compounds in the field of medicine, material and chemical industry. One of the promising accesses to these flexible scaffolds is NAD(P) + -dependent alcohol dehydrogenases-catalyzed oxidative lactonization of diols, which relies on the construction of an efficient NAD(P) + regeneration system. Results In this study, a novel system combining horse liver alcohol dehydrogenase (HLADH) with the synthetic bridged flavin cofactor was established for biosynthesis of lactones. The reaction conditions of this system were optimized and a variety of lactones including chiral lactones were efficiently obtained from various diols. Compared to the previously reported NAD(P) + -regeneration systems, this system showed better regeneration efficiency and product yield. A two-phase system was further applied to solve the problem of product inhibition, and 80% yield was obtained at the condition of 300 mM substrate. Conclusions This study provides an efficient method to synthesis of lactones from diols under mild conditions. We believe this system will be a promising alternative to promote the synthesis of other valuable compounds. Graphic abstract

An interrelated CataFlower enzyme system for sensitively monitoring sweat glucose

Ya Gao,Yu Huang,Junliang Ge,Lei Sun,Anwei Zhou,Shujun Feng,Yurui Xu,Xinghai Ning

An accurate measurement of sweat glucose is a promising alternative to invasive finger prick blood test, and may provide effective self-monitoring of blood glucose with good patient compliance. Herein, an interrelated catalytic enzyme system has been developed, termed as CataFlower, which is composed of nanoflower MoS 2 (peroxidase) decorated with GOx (glucose oxidase) and MnO 2 (oxygen generator), and exhibits synergistic oxidative capability for sensitively monitoring sweat glucose. CataFlower can not only generate oxygen in situ to maximize GOx activity, but promote peroxidase-triggered H 2 O 2 oxidation of methylene blue , resulting in sensitive colorimetric detection of glucose. We identify that CataFlower can precisely detect glucose with a detection limit of 10 μM, allowing for measuring glucose levels in different biological samples, such as blood and urine. Particularly, CataFlower is capable of monitoring dynamic changes in sweat glucose with high sensitivity and accuracy during exercise. Therefore, CataFlower provides a stepping stone to eliminate invasive blood tests, significantly improving the diagnosis and management of diabetes mellitus.

An all-climate CFx/Li battery with mechanism-guided electrolyte

Zhong Fang,Yang Yang,Tianle Zheng,Nan Wang,Congxiao Wang,Xiaoli Dong,Yonggang Wang,Yongyao Xia

High-energy-density CF x /Li batteries have attracted wide applications, but encountered poor environmental adaptability at high/low temperatures. Guided with unique electrolyte-involved reaction mechanism, propylene carbonate (PC)/methyl butyrate (MB) co-solvent formulation was optimized to tune the desolvation barrier and stability for wide temperature operation. Weak affinity of Li + -MB and unique solvation structure of electrolyte, which facilitated easy desolvation at both high rate and low temperature, were uncovered with theoretical calculations and spectra characterizations. Desolvation process from intermediate and percolation-type reaction were clearly revealed with in-situ FT-IR and ex-situ TEM. The synergistic effect of handy desolvation with fast kinetics at the interface enabled excellent rate performance (1C, 834 mAh g −1 ) at +25°C and high capacity (240 mAh g −1 ) at low temperature of -70°C. Simultaneously, the stability of electrolyte assisted to realize high-temperature tolerance up to +95°C. The mechanism-guided electrolyte design offers deep understanding and novel strategy to improve CF x /Li batteries for wide temperature applications.

An Anti-Swellable Hydrogel Strain Sensor for Underwater Motion Detection

Jiayuan Ren,Yanhui Liu,Zengqiang Wang,Siqi Chen,Yifan Ma,Hua Wei,Shaoyu Lü

Hydrogel-based wearable electronic devices have received increasing attention. However, the construction of underwater strain sensors remains a significant challenge because of the swelling of hydrogels in an aquatic environment. This work presents the fabrication of an anti-swellable hydrogel composed of polyvinyl alcohol (PVA), a copolymer of [2-(methacryloyloxy) ethyl]dimethyl-(3-sulfopropyl) ammonium hydroxide (SBMA) and 2-hydroxyethyl methacrylate. Interestingly, facile switch of the SBMA moiety from neutral to positively charged status at a low pH value leads to reduced osmotic pressure of the hydrogel for electrostatic repulsion-driven elimination of water molecules and anti-swelling. The resulting anti-swellable hydrogel exhibits high toughness (518 kJ m −3 ) and compressive modulus (8.12 Mpa), ionic conductivity (up to 4.58 S m −1 ), and anti-swelling behavior (equilibrium swelling ratio of 9% in water for 30 days). An underwater strain sensor based on this anti-swellable hydrogel is further developed to monitor the movements of underwater sports. High sensitivity is achieved to identify multidirectional motions, including raising the head, swinging the arm, bending the elbow, knee and finger. Therefore, this study offers a facile strategy to generate hydrogel-based sensors that can be adopted in an underwater environment as well as expands the potential applications of wearable electronic devices.

Multilayer Tribofilm: An Unique Structure to Strengthen Interface Tribological Behaviors

Ping Wen,Yongzhen Lei,Qianqian Yan,Yunyan Han,Mingjin Fan

Tribofilm configuration under the boundary lubrication region is an essential concern to gain insight into the tribological enhancement of the two-dimensional (2D) nano materials toward base oils. In this work, several alkyl carboxylic acids modified 2D triazine-based covalent organic frameworks (ATC) nano platelets were fabricated and served as lubrication additives. When carbon atoms add up to 16, the best lubricating performance is exhibited at an additive concentration of 0.05 wt % and the friction coefficient and wear volume are, respectively, reduced by 56.0% and 89.6% as compared to those of pure PAO 10 base oil. The analysis of the focused ion beam-transmission electron microscope (FIB-TEM) on the worn surface reveals that an alternately multilayer tribofilm consisting of 2D platelet additives and oxides and/or metallic soap salts is formed on the frictional interface of steel substrate, with a well-ordered arrangement along the sliding direction, which dominates the contributions of the excellent lubrication.

An integrated giant polyoxometalate complex for photothermally enhanced catalytic oxidation

Xiaofei Chen,Guohua Zhang,Bao Li,Lixin Wu

A strategy integrating near infrared (NIR) photothermal and catalytic effects within one active center beyond ultraviolet and visible light is proposed without the combination of separated photothermal transformation components. A giant polyoxomolybdate, which has high NIR photothermal conversion efficiency, is selected as the model catalyst, while a cationic β-cyclodextrin is used to cover its negatively charged surface electrostatically. Under NIR light radiation, the designed catalyst increases catalytic activity of cyclohexene oxidation under O2 atmosphere in water. The conversion reaches about pentaploid of the reaction without NIR radiation. By excluding heating effect from the external heater at the same temperature, about twice as much enhancement, which can be attributed to the sole photothermal action, is still observed. While the catalytic center is shielded by the organic porous layer, the surface cavity allows the integrated catalyst to conduct a selective catalysis by screening the molecules in size over the surface channel.

Polyimide aerogels using melamine as an economical yet effective crosslinker

Liu Sha,Chen Weiwang,Zhou Xiaomeng

Polyimide (PI) aerogels with crosslinked structure are promising for diverse applications owing to their nano-porous nature and superior properties in many aspects. However, the crosslinkers used for preparing crosslinked PI aerogels are always laboriously available and expensive. The economical melamine therefore was chosen as a substitute in this study. It was proved that the use of melamine was indeed a viable strategy for effectively crosslinking PI chains. The resultant melamine-crosslinked PI (MPI) aerogels were tested to have relatively low shrinkage (as low as 9.96 vol%), ultralight bulk densities (0.084–0.116 g cm −3 ) and low thermal conductivity (< 40.0 mW m −1  K −1 ), together with considerable thermal stability (onset temperature to decompose up to 503 ℃) and acceptable compressive strength (Young’s modulus of 1.12–10.04 MPa). Meanwhile, the morphology and properties of MPI aerogels can also be tailored by regulating the proportion of hybrid diamines as well as the polymer concentration of pristine solution. Given all of these, MPI aerogels using melamine as an economical yet effective crosslinker will have a broad prospect in many fields including thermal insulation.

Cobalt phthalocyanine as an efficient catalyst for hydrogen evolution reaction

Lifang Chen,Rizwan Ur Rehman Sagar,Jun Chen,Juan Liu,Sehrish Aslam,Farhat Nosheen,Tauseef Anwar,Naveed Hussain,Xinmei Hou,Tongxiang Liang

Hydrogen production from water splitting is highly desired for the green and clean energy device but remains a great challenge. In this regard, cobalt-phthalocyanine (PyCoPc) and composite of PyCoPc with graphene oxide (GO) were fabricated and used as catalyst for the energy conversion. The as-synthesized PyCoPc/GO exhibits an efficient hydrogen evolution reaction due to the low overpotential ~253 mV at a 10 mA cm −2 current density with a Tafel slope ~96 mV dec −1 in alkaline media . Our study reveals that the active area of the catalyst was controlled with the help of π − π stacking interaction between GO and PyCoPc. Technologically, a highly efficient PyCoPc catalyst was developed for hydrogen evolution reaction.

Solid-state Al-air battery with an ethanol gel electrolyte

Yifei Wang,Wending Pan,Kee Wah Leong,Shijing Luo,Xiaolong Zhao,Dennis Y.C. Leung

Hydrogel electrolyte is especially suitable for solid-state Al-air batteries targeted for various portable applications, which may, however, lead to continuous Al corrosion during battery standby. To tackle this issue, an ethanol gel electrolyte is developed for Al-air battery for the first time in this work, by using KOH as solute and polyethylene oxide as gelling agent. The ethanol gel is found to effectively inhibit Al corrosion compared with the water gel counterpart, leading to stable Al storage. When assembled into an Al-air battery, the ethanol gel electrolyte achieves a much improved discharge lifetime and specific capacity, which are 5.3 and 4.1 times of the water gel electrolyte at 0.1 mA cm −2 , respectively. By studying the gel properties, it is found that a lower ethanol purity can improve the battery power output, but at the price of decreased discharge efficiency. On the contrary, a higher polymer concentration will decrease the power output, but can bring extra benefit to the discharge efficiency. As for the gel thickness, a moderate value of 1 mm is preferred to balance the power output and energy efficiency. Finally, to cater the increasing market of flexible electronics, a flexible Al-air battery is developed by impregnating the ethanol gel into a paper substrate, which can function normally even under serious deformation or damage.