High thermal conductivity of flexible polymer composites due to synergistic effect of multilayer graphene flakes and graphene foam

Research on flexible thermal interface materials (TIMs) has shown that the interconnected network of graphene foam (GF) offers effective paths of heat transportation. In this work, a variant amount of multilayer graphene flakes (MGFs) was added into 0.2 vol% GF/polydimethylsiloxane (PDMS) composite. A remarkable synergistic effect between MGF and GF in improving thermal conductivity of polymer composites is achieved. With 2.7 vol% MGFs, the thermal conductivity of MGF/GF/PDMS composite reaches 1.08 W m⁻¹ K⁻¹, which is 80%, 184% and 440% higher than that of 2.7 vol% MGF/PDMS, GF/PDMS composites and pure PDMS, respectively. The MGF/GF/PDMS composite also shows superior thermal stability. The addition of MGFs and GF decreases slightly the elongation at break, but observably increases the Young’s modulus and tensile strength of composites compared with pure PDMS. The good performance of MGF/GF/PDMS composite makes it a good TIM for possible application in thermal management of electronics.     

Properties of a Binary System Containing Anionic and Cationic Gemini Surfactants

Surface tension, fluorescence, and dynamic light scattering were used to investigate the properties of a binary surfactant system comprising an anionic gemini surfactant (DLMC) and cationic gemini surfactant (II‐12‐EO₂). Surface tension measurements afforded the critical micelle concentration (cmc) of the mixture and the values are all lower than those of pure constituent surfactants. For the mixtures of II‐12‐EO₂/DLMC, the micelle aggregation number decreases with the increase of II‐12‐EO₂, and the micropolarity of the micelle is lowest when the molar fraction of II‐12‐EO₂ is 0.5; the hydrodynamic radius (R_h) of the mixed micelle first increases and then decreases with the addition of II‐12‐EO₂, and larger micelles are obtained when the molar fraction of II‐12‐EO₂ is 0.5 or 0.7.     

受阻胺光稳定剂和抗氧剂并用对聚合物紫外光稳定性的影响

阐述了受阻胺稳定剂(HALS)和抗氧剂的分类和作用机理,重点介绍了受阻胺类光稳定剂和抗氧剂并用对聚合物紫外光降解中的影响。当受阻胺类光稳定剂和抗氧剂并用时,既有协同效应,又有对抗效应,也有加和效应。这依赖于受阻胺类光稳定剂和抗氧剂的种类。同时介绍受阻胺光稳定剂发展的趋势。     

Effects of Cr3C2 addition on the erosion–corrosion resistance of Ti(C,N)-based cermets in alkaline conditions

Effects of Cr₃C₂ on the erosion–corrosion behavior of Ti(C,N)-based cermets are studied in alkaline conditions. The results indicate that the erosion–corrosion resistance of cermets is improved with proper Cr₃C₂ content. Corrosion performance of cermets is deteriorated by Cr₃C₂ addition in NaOH solution. With the increase of Cr₃C₂, the erosion–corrosion behavior of Ti(C,N)-based cermets is classified to be erosion regime, erosion–corrosion regime, corrosion–erosion regime and corrosion regime. Materials degradation is determined by particles erosion for cermets with low Cr₃C₂ content, while for materials containing more Cr₃C₂ addition, binder corrosion and subsequent erosion are responsible for materials deterioration.     

Tribocorrosion behaviour of TiCxOy thin films in bio-fluids

Decorative coatings require not only an attractive appearance for market applications, but also an ability to protect the surface underneath. Because of this, corrosion, wear and their combined effects (termed tribocorrosion) are particularly important for lifetime prediction. In this paper, the tribocorrosion behaviour of a range of single layered titanium oxycarbide, TiC_xO_y, coatings, produced by DC reactive magnetron sputtering, has been studied and reported as a function of electrode potential and applied load. The study was conducted in a reciprocating sliding tribo-system (Plint TE 67/E) in a bio-fluid (an artificial perspiration solution) at room temperature. During the wear tests, both the open-circuit potential and the corrosion current were monitored. The results showed that electrode potential and load have a significant influence on the total material loss. The variations in R_p (polarization resistance) and C_f (capacitance) before and after sliding, obtained by Electrochemical Impedance Spectroscopy (EIS) were evaluated in order to provide an understanding of the resistance of the film in such conditions. Tribocorrosion maps were generated, based on the results, indicating the change in mechanisms of the tribological and corrosion parameters for such coatings, as a function of load and applied potential.     

Synergistic effect of green tea polyphenols with trolox on free radical-induced oxidative DNA damage

The antioxidant effect of the principal polyphenolic components extracted from green tea leaves, namely (−)-epicatechin (EC), (−)-epigallocatechin (EGC), (−)-epicatechin gallate (ECG) and (−)-epigallocatechin gallate (EGCG), and their synergistic antioxidant effects with trolox against oxidative DNA damage were studied. The oxidative DNA damage was initiated by a water-soluble azo initiator, 2,2′-azobis (2-amidinopropane hydrochloride) (AAPH) and the ability of green tea polyphenols and/or trolox (a water-soluble analogue of α-tocopherol) to inhibit the oxidative damage of DNA was assessed, in vitro, by measuring the conversion of supercoiled pBR322 plasmid DNA to the open circular and linear forms. It was found that these green tea polyphenols could significantly inhibit the oxidative damage of DNA synergistically with trolox, with an activity sequence of EC = ECG > EGCG > EGC.     

Lactobionic Acid as a New Synergist in Combination with Phosphonate-Zn(Ⅱ)System for Corrosion Inhibition of Carbon Steel

Studies on lactobionic acid introduced as a synergist in the presence of phosphonobutane-1,2,4-tricarboxylic acid(PBTC) and zinc ions for corrosion control of carbon steel in aqueous environment are presented.The investigations revealed that lactobionic acid(LBA) acts as an excellent synergist in corrosion inhibition.Optimum concentrations of all the three components of the ternary formulation are established by gravimetric studies.Potentiodynamic polarization studies indicate that the new ternary system is a mixed inhibitor.Impedance studies show that a protective film is formed on the metal surface in the presence of the inhibitor formulation.The film is found to exhibit its protective nature even at higher temperatures up to 60 °C.Analysis of the protective film by X-ray photoelectron spectroscopy(XPS) and reflection absorption Fourier transform infrared(FTIR) spectroscopy infers the presence of Zn(OH)_2,oxides and hydroxides of iron and the inhibitor molecules in the surface film probably in the form of a complex,[Zn(ll)—PBTC—LBA].The morphological studies by scanning electron microscopy(SEM) and the topographical studies by atomic force microscopy(AFM) also indicate the presence of protective film on the metal surface.A plausible mechanism of corrosion inhibition is proposed.     

褪黑素改善小鼠睡眠作用的研究

为研究褪黑素的改善睡眠作用，通过直接睡眠试验、与戊巴比妥钠协同睡眠试验，观察褪黑素诱导小鼠的睡眠作用。结果显示：褪黑素８００ｍｇ／ｋｇＢＷ剂量灌胃小鼠，有直接诱导小鼠睡眠作用（Ｐ＜０．０１），睡眠时间为７０．８ｍｉｎ，潜伏期为３５．７ｍｉｎ；０．０８３、０．５、３．０ｍｇ／ｋｇＢＷ剂量，能显著延长戊巴比妥钠诱导的小鼠睡眠时间（Ｐ＜０．０１），显著增加戊巴比妥钠阈下剂量诱导的小鼠睡眠发生率（Ｐ＜０．０５、Ｐ＜０．０１）。由此可见，褪黑素具有改善小鼠睡眠作用     

双功能受阻胺与紫外线吸收剂并用的协同效应研究

本文用IR、UV、ESR、TLC等方法研究了新型的双功能受阻胺光稳定剂,Tinuvin-144 [2-(4′-羟基-3′,5′-二叔丁基)苄基-2-正丁基丙二酸五甲基哌啶醇酯]与紫外线吸收剂,UV-531(2-羟基-4-正辛氧基二苯甲酮)和UV-327(2-[2′-羟基-3′,5′-二叔丁基]-5-氯 代苯并三唑)并用体系对聚丙烯光稳定化的并用效应。结果表明,Tinuvin-144与UV-531,UV-327并用时均具有良好的协同效应,144对531,327或531,327对144的光分解均具有相互的保护作用。结果还表明,144与531或327无论在模拟体系或聚丙烯中,在诱导期内均不存在促使他们消耗的化学反应,提出了协同作用的机理。     

加强技术创新体系建设促进企业发展

论述了技术创新在企业降耗增效、生存发展中所起的作用,技术创新体系在企业所处的地位以及建设好技术创新体系的重大意义。