SILICA GRAFTED WITH EPOXIDIZED LIQUID POLYBUTADIENES: ITS BEHAVIOR AS FILLER FOR TIRE TREAD COMPOUNDS

2017 ◽  
Vol 90 (1) ◽  
pp. 173-194 ◽  
Author(s):  
Marcus V. Braum ◽  
Marly A. M. Jacobi

ABSTRACT Achieving high polymer-filler interaction and lowering the energy consumption required to disperse precipitated silica in a rubber matrix have been the main motivations behind the recent interest in silica-coating processes. A simple, low-cost, and environmentally friendly process is available to graft epoxidized liquid polybutadienes onto a silica surface. The polymer-grafted silicas are applied as reinforcing fillers in typical car tire tread compounds. The processability, cure kinetics, and properties of the vulcanizates are greatly affected by the degree of epoxidation, molar mass, and microstructure of the epoxidized polybutadienes used for coating the silica surface. The dynamic-mechanical behavior is superior to that of the reference compound, using bis-[triethoxysilylpropyl] tetrasulfide as a coupling agent, in stiffness and hysteresis at low temperatures, which is indicative of superior performance in wet grip and emergency maneuvers (hard-handling). Thus, the use of this reinforcement system for high-performance car tires, for which safety features should be prioritized, is promising.

2012 ◽  
Vol 455-456 ◽  
pp. 889-894
Author(s):  
Qian Xiang

As anode material of battery, manganese dioxide has been widely used in zinc-manganese and lithium–manganese primary battery. To meet new electrical products’ requirements on high-performance battery, research on rechargeable lithium manganese button batteries with extensive operating temperature, superior-performance comprehensive electrochemistry and low cost has drawn attention from more and more researchers. This article has analyzed physical and chemical properties of lithium manganese composite oxides synthetic material, assembled lithium button batteries by synthetic sample and lithium aluminum alloy and discussed its electrochemistry performance, based on confirmed material proportioning, discussed the influence of roasting condition on synthetic material performance from physical & chemical properties and electrochemistry properties, and confirmed best roasting temperature and roasting time.


2012 ◽  
Vol 1427 ◽  
Author(s):  
Hamid Kiumarsi ◽  
Hiroyuki Ito ◽  
Noboru Ishihara ◽  
Kenichi Okada ◽  
Yusuke Uemichi ◽  
...  

ABSTRACTA 60 GHz tandem coupler using offset broadside coupled lines is proposed in a WLP (Wafer Level Packaging) technology. The fabricated coupler has a core chip area of 750 μm × 385 μm (0.288 mm2). The measured results show an insertion loss of 0.44 dB, an amplitude imbalance of 0.03 dB and a phase difference of 87.6° at 60 GHz. Also the measurement shows an insertion loss of less than 0.67 dB, an amplitude imbalance of less than 0.31 dB, a phase error of less than 3.7°, an isolation of more than 29.7 dB and a return loss of more than 27.9 dB at the input ant coupled ports and more than 14.3 dB at the direct and isolated ports over the frequency band of 57-66 GHz, covering 60 GHz band both in Japan and US. To the best of our knowledge the proposed coupler achieves the lowest ever reported insertion loss and amplitude imbalance for a 3-dB coupler on a silicon substrate. With its superior performance and lower cost compared to the CMOS counterparts, the proposed coupler is a suitable candidate for low-cost high-performance millimeter-wave systems.


2019 ◽  
Vol 13 (02) ◽  
pp. 2051002
Author(s):  
Shaowei Lu ◽  
Junchi Ma ◽  
Keming Ma ◽  
Shuai Wang ◽  
Xiangdong Yang ◽  
...  

High-performance pressure sensors have caused widespread concern due to the potential applications in 3D-touch technology and wearable electronic devices. Herein, a new type of graphene pressure sensor based on the glass fiber surfacing mat coated with graphene oxide aqueous solution by a spray-vacuum filtration method and HI acid reduction method is reported. It is a simple and highly effective method to reduce graphene oxide films into highly conductive graphene films without destroying their integrity and flexibility at a low temperature based on the nucleophilic substitution reaction. The FTIR, SEM and conductivity tests indicate that the optimum time for graphene oxide to be reduced is 30[Formula: see text]min, under this condition enter the epoxy group has been reacted without damaging the regular sp2 hybrid C atom structure in graphene. The conductivity of the graphene pressure sensor is increased significantly to 23260[Formula: see text]S/m. The monotonic compressing test for 100[Formula: see text]Pa/s and the test of the metal block placement and removal demonstrate that the sensor exhibits relatively high linearity of 99.74% between the response and pressure, the advantage makes the sensor monitor pressure more accurately. More importantly, the pressure sensor based on the glass fiber surfacing mat coated with graphene shows extremely high sensitivity (0.169[Formula: see text][Formula: see text]), fast response time (251[Formula: see text]ms) and good stability for 1000 cycles. Based on its superior performance, it also demonstrates potential applications in measuring pressure and human body’s motions.


Author(s):  
Mingtan Wang ◽  
Wenjing Lu ◽  
Huamin Zhang ◽  
Xianfeng Li

Abstract The demands for high-performance and low-cost batteries make K-ion batteries (KIBs) considered as promising supplements or alternatives for Li-ion batteries (LIBs). Nevertheless, there are only a small amount of conventional inorganic electrode materials that can be used in KIBs, due to the large radius of K+ ions. Differently, organic electrode materials (OEMs) generally own sufficiently interstitial space and good structure flexibility, which can maintain superior performance in K-ion systems. Therefore, in recent years, more and more investigations have been focused on OEMs for KIBs. This review will comprehensively cover the researches on OEMs in KIBs in order to accelerate the research and development of KIBs. The reaction mechanism, electrochemical behavior, etc., of OEMs will all be summarized in detail and deeply. Emphasis is placed to overview the performance improvement strategies of OEMs and the characteristic superiority of OEMs in KIBs compared with LIBs and Na-ion batteries.


Author(s):  
Da-Ming Feng ◽  
Ying Sun ◽  
Zhong-Yong Yuan ◽  
Yang Fu ◽  
Baohua Jia ◽  
...  

AbstractThe electrochemical production of green and low-cost ammonia requests the development of high-performance electrocatalysts. In this work, the ampoule method was applied to modulate the surface of the zinc electrode by implanting defects and low-valent active sites. The N-doped ZnS electrocatalyst was thus generated by sulfurization with thiourea and applied for electrocatalytic nitrogen reduction reaction (ENRR). Given the rich sulfur vacancies and abundant Zn-N active sites on the surface, excellent catalytic activity and selectivity were obtained, with an NH3 yield rate of 2.42 × 10–10 mol s−1 cm−2 and a Faradaic efficiency of 7.92% at − 0.6 V vs. RHE in 0.1 M KOH solution. Moreover, the as-synthesized zinc electrode exhibits high stability after five recycling tests and a 24 h potentiostatic test. The comparison with Zn foil, non-doping ZnS/Zn and recent metal sulfide electrocatalysts further demonstrated advanced catalytic performance of N@ZnS/Zn for ENRR. By simple synthesis, S vacancies, and N-doping defects, this promising electrocatalyst would represent a good addition to the arena of transition-metal-based catalysts with superior performance in ENRR. Graphic abstract


2020 ◽  
Vol 16 (3) ◽  
pp. 246-253
Author(s):  
Marcin Gackowski ◽  
Marcin Koba ◽  
Stefan Kruszewski

Background: Spectrophotometry and thin layer chromatography have been commonly applied in pharmaceutical analysis for many years due to low cost, simplicity and short time of execution. Moreover, the latest modifications including automation of those methods have made them very effective and easy to perform, therefore, the new UV- and derivative spectrophotometry as well as high performance thin layer chromatography UV-densitometric (HPTLC) methods for the routine estimation of amrinone and milrinone in pharmaceutical formulation have been developed and compared in this work since European Pharmacopoeia 9.0 has yet incorporated in an analytical monograph a method for quantification of those compounds. Methods: For the first method the best conditions for quantification were achieved by measuring the lengths between two extrema (peak-to-peak amplitudes) 252 and 277 nm in UV spectra of standard solutions of amrinone and a signal at 288 nm of the first derivative spectra of standard solutions of milrinone. The linearity between D252-277 signal and concentration of amironone and 1D288 signal of milrinone in the same range of 5.0-25.0 μg ml/ml in DMSO:methanol (1:3 v/v) solutions presents the square correlation coefficient (r2) of 0,9997 and 0.9991, respectively. The second method was founded on HPTLC on silica plates, 1,4-dioxane:hexane (100:1.5) as a mobile phase and densitometric scanning at 252 nm for amrinone and at 271 nm for milrinone. Results: The assays were linear over the concentration range of 0,25-5.0 μg per spot (r2=0,9959) and 0,25-10.0 μg per spot (r2=0,9970) for amrinone and milrinone, respectively. The mean recoveries percentage were 99.81 and 100,34 for amrinone as well as 99,58 and 99.46 for milrinone, obtained with spectrophotometry and HPTLC, respectively. Conclusion: The comparison between two elaborated methods leads to the conclusion that UV and derivative spectrophotometry is more precise and gives better recovery, and that is why it should be applied for routine estimation of amrinone and milrinone in bulk drug, pharmaceutical forms and for therapeutic monitoring of the drug.


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