Capillarity-Driven Self-Assembly of Silver Nanowires-Coated Fibers for Flexible and Stretchable Conductor

Yi Li,Jun Chen,Xiao Han,Yinghui Li,Ziqiang Zhang,Yanwen Ma 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2018 NANO Vol.13 No.12

The rapid development of smart textiles requires the large-scale fabrication of conductive fibers. In this study, we develop a simple, scalable and low-cost capillary-driven self-assembly method to prepare conductive fibers with uniform morphology, high conductivity and good mechanical strength. Fiber-shaped flexible and stretchable conductors are obtained by coating highly conductive and flexible silver nanowires (Ag NWs) on the surfaces of yarn and PDMS fibers through evaporation-induced flow and capillary-driven self-assembly, which is proven by the in situ optical microscopic observation. The density of Ag NWs and linear resistance of the conductive fibers could be regulated by tuning the assembly cycles. A linear resistance of 1.4Ω/cm could be achieved for the Ag NWs-coated nylon, which increases only 8% after 200 bending cycle, demonstrating high flexibility and mechanical stability. The flexible and stretchable conductive fibers have great potential for the application in wearable devices.

A novel membrane on pervaporation performance for dehydration of Caprolactam solution

Qin Li,Yanwen Lin,Tianrong Zhu,Yunbai Luo,Ping Yu 한국공업화학회 2012 Journal of Industrial and Engineering Chemistry Vol.18 No.2

Konjac glucomannan (KGM) is a kind of polysaccharide with wide applications, except in pervaporation (PV). This article focuses on the new function of KGM and simultaneously improving a new dehydration process for e-Caprolactam (CPL). KGM was cross-linked with glutaraldehyde (GA) at proportions of 0.3,0.5, and 0.7 wt%. Cross-linked membranes were characterized by scanning electron microscope, Fourier transform-infrared, and X-ray diffraction to assess the membranes of morphology, intermolecular interactions, and observe the effects of cross-linking on crystallinity, respectively. Cross-linked KGM as the active layer of the composite membranes has the net matrix structure, and many characteristics improved compared with pure KGM. Data showed that KGM cross-linked with GA displayed good swelling and PV performance, and the composite membranes had superior separation performances in dehydrating the CPL solution. The highest separation factor could reach 3531. The study provided a new way for both KGM application and CPL dehydration.

Deciphering the neuroprotective effect of ascorbic acid mediated synthesis of iron oxide nanoparticles against Parkinson’s disease: an in vitro and in vivo approach

Linxi Li,Ping Luo,Shaochang Wu,Yanwen Wang 한국고분자학회 2023 Macromolecular Research Vol.31 No.10

One of the most prevalent neurological movement diseases affecting the geriatric population globally is Parkinson’s disease (PD). Recent studies have highlighted the potency of biomolecules in the generation of nanomaterials and also over their impact on neuroprotection. The objective of this research was to investigate the potential of iron oxide nanoparticles produced using ascorbic acid (AA-IONPs) against PD. Numerous analytical methods including UV–Vis analysis, Fourier-Transform Infrared Spectroscopy (FTIR), dynamic light scattering (DLS), and electron microscopy (SEM, TEM), were used to analyze the produced AA-IONPs. Nitric oxide, prostaglandin E2, and inflammatory cytokines analyses such as IL-6 and IL-1 were employed to assess the neuroprotective effect of synthesized AA-IONPs on inflammatory agent lipopolysaccharides driven murine microglial BV2 cells. And also Parkinson-induced C57BL/6 mice were given the nanoparticle treatment to confirm the in vivo effects of the produced nanoparticles. Our characterization findings had demonstrated that AA-IONPs have a significant role in acting as an ideal nano drug and may have the ability to reduce inflammation in in vitro murine microglial BV2. The outcomes of in vivo tests conclusively show that AA-IONPs had reduced neuroinflammation and enhanced motor coordination in Parkinson’s disease-induced rats.

Molecular Design and Engineering of Phosphopeptide Ligands to Target Lung Cancer Polo-like Kinase

Xiyan Yu,Yanwen Li,Ying Lou,Tong Wang 한국생물공학회 2017 Biotechnology and Bioprocess Engineering Vol.22 No.2

Polo-like kinase (Plk) plays a central role in centrosome cycle and is closely associated with the oncogenesis of lung cancer. The protein consists of a catalytic kinase domain (KD) and a regulatory polo-box domain (PBD); either direct inhibition of the KD’s catalytic activity or indirect disruption of the PBD–substrate interaction can be used to potentially suppress the pathological activation of lung cancer Plk. Here, we reported a successful molecular design and engineering of phosphopeptide ligands to target Plk PBD domain by integrating in silico modeling and in vitro assay. In the procedure, a helical peptide segment hps was derived from dimerization interface of the complex crystal structure of domain dimer using bioinformatics approach, which was then used as sequence template to generate potent phosphopeptide binders of Plk PBD domain in terms of a systematic residue mutation profile. Fluorescence anisotropy assays were conducted to substantiate the findings and conclusions obtaining from the molecular engineering. Consequently, three helical phosphopeptides, including the native hps and its two mutants hps-m1 and hps-m2, were successfully designed that can independently rebind to Plk PBD domain with a moderate or high affinity (Kd = 127, 26, and 5 μM, respectively). These peptide ligands can be considered as potent self-competitors to disrupt PBD dimerization in lung cancer metastasis. Structural and energetic analysis revealed that hydrophobic forces and van der Waals contacts confer strong stability for domain–peptide complex system, while hydrogen bonds and electrostatic interactions contribute specificity and selectivity to the complex recognition.

Design of a Wireless Monitoring Network for Granary Temperature and Humidity Based on Zigbee

Jingwei Dong,Huile Li,Yuan Liu,Yanwen Guo,Guanhua Tang 보안공학연구지원센터(IJUNESST) 2014 International Journal of u- and e- Service, Scienc Vol.7 No.2

A wireless high-frequency anemometer instrumentation system for field measurements

Guoqing Huang,Liuliu Peng,Yanwen Su,Haili Liao,Mingshui Li 한국풍공학회 2015 Wind and Structures, An International Journal (WAS Vol.20 No.6

Field measurement of wind characteristics is of great significance for the wind engineering community. High-frequency anemometers such as ultrasonic anemometers are widely used to obtain the high-frequency fluctuating wind speed time history. However, conventional instrumentation systems may suffer from low efficiency, non-real time transmission and higher maintenance cost, and thus are not very appropriate in the field measurement of strong winds in remote areas such as mountain valleys. In order to improve the field measurement performance in those remote areas, a wireless high-frequency anemometer instrumentation system for field measurement has been developed. In this paper, the architecture of the proposed instrumentation system, and measured data transmission and treatment will be presented firstly. Then a comparison among existing instrumentation systems and the proposed one is made. It shows that the newly-developed system has considerable advantages. Furthermore, the application of this system to the bridge site located in the mountain valley is discussed. Finally, typical samples of measured data from this area are presented. It can be expected that the proposed system has a great application potential in the wind field measurement for remote areas such as the mountainous or island or coastal area, and hazardous structures such as ultra-voltage transmission tower, due to its real-time transmission, low cost and no manual collection of data and convenience.

Electrochemical Polishing of Additively Manufactured Ti–6Al–4V Alloy

Yifei Zhang,Jianzhong Li,Shuanghang Che,Yanwen Tian 대한금속·재료학회 2020 METALS AND MATERIALS International Vol.26 No.6

In this present paper, the electropolishing behavior of Ti–6Al–4V alloy fabricated by additive manufacturing in chloridecontainingethylene glycol electrolyte was surveyed. The impacts of chloride ion on surface quality and oxide film ofTi–6Al–4V were analyzed in dependence on the surface topography, roughness, weight loss ratio and compositions. Thevisual and microscopic results revealed that the optimally electropolished surface was attained in a 0.4 mol L−1 chlorideelectrolyte with a decreased surface roughness of 75.04% and a weight loss rate of 4.93%. For lower (CCl−1 ≤ 0.3 mol L−1)or higher concentrations (CCl−1 ≥ 0.5 mol L−1), a smooth and flat surface was not observed due to insufficient reactions orexcessive anodic dissolution. During the electropolishing, the titanium oxides nucleated and corresponding surface tensionincreased, resulting in the formation of a stable TiO2film on the surface of the Ti–6Al–4V alloy, increasing the corrosionresistance of the specimen.

A wireless high-frequency anemometer instrumentation system for field measurements

Huang, Guoqing,Peng, Liuliu,Su, Yanwen,Liao, Haili,Li, Mingshui Techno-Press 2015 Wind and Structures, An International Journal (WAS Vol.20 No.6

Field measurement of wind characteristics is of great significance for the wind engineering community. High-frequency anemometers such as ultrasonic anemometers are widely used to obtain the high-frequency fluctuating wind speed time history. However, conventional instrumentation systems may suffer from low efficiency, non-real time transmission and higher maintenance cost, and thus are not very appropriate in the field measurement of strong winds in remote areas such as mountain valleys. In order to improve the field measurement performance in those remote areas, a wireless high-frequency anemometer instrumentation system for field measurement has been developed. In this paper, the architecture of the proposed instrumentation system, and measured data transmission and treatment will be presented firstly. Then a comparison among existing instrumentation systems and the proposed one is made. It shows that the newly-developed system has considerable advantages. Furthermore, the application of this system to the bridge site located in the mountain valley is discussed. Finally, typical samples of measured data from this area are presented. It can be expected that the proposed system has a great application potential in the wind field measurement for remote areas such as the mountainous or island or coastal area, and hazardous structures such as ultra-voltage transmission tower, due to its real-time transmission, low cost and no manual collection of data and convenience.

Robust Adaptive Sliding‑Mode Control for Permanent Magnet Spherical Actuator with Uncertainty Using Dynamic Surface Approach

Yan Wen,Guoli Li,Qunjing Wang,Xiwen Guo 대한전기학회 2019 Journal of Electrical Engineering & Technology Vol.14 No.6

This paper presents a position tracking control method for a three degree-of-freedom permanent magnet spherical actuator (PMSA). The control method is designed based on a dynamic model of the PMSA with uncertainties including modelling errors and external disturbance. Sliding-mode surface are adopted to restrain and eliminate the efect of external disturbances. To compensate modelling errors, an adaptive law is employed to estimate unknown model parameters so that model information can be updated in real time. By the use of dynamic surface approach, three frst-order flters are introduced to avoid the explosion of derivative terms caused by traditional adaptive backstepping approach. The stability of the closed-loop system using the proposed controller is confrmed through Lyapunov theorem. The test bench consisted of the prototype of PMSA, the host computer, the current controller and the orientation detection device is established for experiments. Simulation and experimental results are provided to validate efectiveness of the proposed method.