液晶离聚物/PEO固体聚合物电解质的研究

采用溶液铸膜法制备了含磺酸离子液晶离聚物(LCI)-PEO-高氯酸锂全固态聚合物电解质(SPE)。运用扫描电镜、数字显微镜、差示扫描量热法(DSC)、拉伸测试和交流阻抗对复合电解质膜的性能进行了表征,研究了液晶离聚物(LCI)对电解质结晶度、力学性能以及电导率的影响。结果表明,液晶离聚物(LCI)的加入虽然增加了聚合物电解质的结晶度,但是提高了电导率。当液晶离聚物(LCI)含量为3%时,电解质的室温电导率达最大值,为1.30×10-5S/cm。

PEO-PPO-PTHF-PPO-PEO嵌段共聚醚的合成与应用

为了改善聚氨酯薄膜的易结晶性与力学性能,从原料聚醚着手,以聚四氢呋喃醚二醇(PTMG1000)为起始剂,以一定比例的环氧乙烷和环氧丙烷为原料,通过阴离子开环聚合机理进行四氢呋喃嵌段聚醚(PTMGPO/EO)的合成.分别使用红外、核磁共振及凝胶渗透色谱对所合成聚醚多元醇进行分析、表征,并以合成的PTMG-PO/EO聚醚为原料制作聚氨酯薄膜,与常规PEO聚醚所制成的聚氨酯薄膜进行力学性能与透湿性能的比较.结果表明:PUPTMG-PO/EO薄膜透湿量为10 288 g/(m2·(24 h)),PUPTMG-PO/EO薄膜断裂强度为35 MPa,断裂伸长率为550%,使用所合成的PTMG-PO/EO聚醚制成的聚氨酯薄膜具有高的力学性能与良好的透湿性.

以PEO-b-PtBA及PEO-b-PAA为模板制备聚联苯胺及其电化学性能研究

以两嵌段共聚物聚氧化乙烷-b-聚丙烯酸叔丁酯(PEO-b-Pt BA)及其水解产物聚氧化乙烷-b-聚丙烯酸(PEO-b-PAA)为模板制备了亚微米至纳米级棒状聚联苯胺(PBz)颗粒。利用红外光谱、核磁共振、透射电镜及循环伏安和交流阻抗等测试了PBz的结构、形貌和电化学性能。结果表明,嵌段共聚物为模板合成的PBz呈现棒状分布,颗粒直径均小于200 nm且部分在100 nm以内。PBz颗粒形貌均匀,尺寸均一,使用有机溶剂溶解嵌段共聚物模板未对PBz颗粒形貌产生影响。不同模板合成的PBz均具有一定的电化学活性,以PEO-b-PAA为模板得到的各样品电化学性能优于PEO-b-Pt BA为模板的情况。在电流密度为1 A/g时,材料比电容最高达到了263 F/g。

Effect of catalyst on structure of(PEO)_8LiClO_4-SiO_2 composite polymer electrolyte films

(PEO)8LiClO4-SiO2 composite polymer electrolytes(CPEs)were prepared by in-situ reaction,in which ethyl-orthosilicate(TEOS)was catalyzed by HCl and NH3.H2O,respectively.The ionic conductivity,the contact angle and the morphology of inorganic particles in the CPEs were investigated by AC impedance spectra,contact angle method and TEM.The conductivities of acid-catalyzed CPE and alkali-catalyzed CPE are 2.2×10-5and 1.1×10-5S/cm respectively at 30℃.The results imply that the catalyst plays an important role in the structure of in-situ preparation of SiO2,and influences the surface energy and conductivity of CPE films directly.Meanwhile,the ionic conductivity is related to the surface energy.

A novel coral-like garnet for high-performance PEO-based all solid-state batteries

As one of the most promising next-generation energy storage devices,the lithium-metal battery has been extensively investigated.However,safety issues and undesired lithium dendrite growth hinder its development.The application of solid-state electrolytes has attracted increasing attention as they can solve safety issues and show great potential to inhibit the growth of lithium dendrites.Polyethylene oxide(PEO)-based electrolytes are very promising due to their enhanced safety and excellent flexibility.However,they suffer from low ionic conductivity at room temperature and cannot effectively inhibit lithium dendrites at high temperatures due to the intrinsic semicrystalline properties and poor mechanical strength.In this work,a novel coral-like Li_(6.25)Al_(0.25)La_(3)Zr_(2)O_(12)(C-LALZO)is synthesized to serve as an active ceramic filler in PEO.The PEO with LALZO coral(PLC)exhibits increased ionic conductivity and mechanical strength,which leads to uniform deposition/stripping of lithium metal.The Li symmetric cells with PLC do not cause a short circuit after cycling for 1500 h at 60℃.The assembled LiFePO_(4)/PLC/Li batteries display excellent cycling stability at both 60 and 50℃.This work reveals that the electrochemical properties of the composite electrolyte can be effectively improved by tuning the microstructure of the filler,such as the C-LALZO architecture.

High-yield preparation of robust gold nanoshells on silica nanorattles with good biocompatiblity

Although gold nanoshells are widely considered as one of the promising photothermal nanomaterials used for biomedicine, the high cost, low yield and poor stability severely limit their potential application in clinical trials.Herein, robust gold nanoshells on silica nanorattles(GSNs)were easily prepared in a high yield by an improved seedmediated method employing polyvinylpyrrolidone(PVP) as a stabilizing and capping agent. The present method is very simple, effective and reproducible and can well control the growth process of gold nanoshells. The as-prepared GSNs have a narrow size distribution(<10 % in standard deviation). Furthermore, the utilization rate of Au in the solution used for the growth of gold nanoshells increases by 70 %than that in previous method. The resultant GSNs have a good structural stability after placing over 6 months due to the protection of PVP. More importantly, in vivo and in vitro toxic studies indicate that the GSNs have good biocompatibility. We believe that our preparation method will remarkably promote the use of gold nanoshells for biomedicine.

Polyvinylpyrrolidone/graphene oxide thin films coated on quartz crystal microbalance electrode for NH_3 detection at room temperature

In this paper, composite film based on polyvinylpyrrolidone(PVP)/graphene oxide(GO) was fabricated by spray method on AT-cut 9.986 MHz quartz crystal microbalance(QCM) for NH_3 sensing. The thin films were characterized by scanning electron microscope(SEM), Fourier transform infrared spectroscopy(FTIR) and ultraviolet-visible spectroscopy(UV-VIS) to investigate the morphologies and the composition contents, respectively. The experimental results reveal that PVP/GO based sensor holds higher sensitivity, larger responsiveness and smaller baseline drift than those based on pure PVP at room temperature. Besides, the prepared sensor exhibits greater response to NH_3 than other gases such as CO, CO_2 and NO_2 at the same concentration. The good linearity, reproducibility and stability demonstrate the practicability of PVP/GO hybrid film in detecting NH_3.

Electrochemical behavior of hemoglobin in neutral surfactants with different poly(ethylene oxide) unit lengths adsorbed on an electrode

The direct electron transfer and adsorption behavior of hemoglobin(Hb) in a series of surfactants with different poly(ethylene oxide)(PEO) unit lengths on a glassy carbon electrode have been studied.With a surfactant of appropriate PEO unit length,the surfactant film-modified electrode exhibited a more stable adsorption state with a larger surface coverage of Hb and a more positive formal potential,which can be attributed to the effect of hydrogen bonding between proteins and surfactants.The electrochemical behavior of surfactants with different PEO unit lengths is discussed in detail.Moreover,UV-visible spectroscopy demonstrated that the structure of Hb was not destroyed in the surfactant films.The electrocatalytic activity of hydrogen peroxide on three neutral surfactant-modified electrodes has also been investigated.

Synthesis and adsorptivity of acryloylmorpholine resin to various fission product elements in nitric acid media

A novel silica-supported resin with a cyclic monoamide of polymerized 4-acryloylmorpholine(Silica-AM) was synthesized, and adsorptivity to metal ions of major fission products(FP) was examined in HNO3 and HCl solutions. Silica-AM has a carbonyl oxygen atom outside of the 6-membered morpholine ring, and a cyclic structure that is different than other cyclic monoamide resins we have studied. These include polyvinylpolypyrrolidone(PVPP) and poly-N-vinyl-ε-caprolactam(VEC), both of which have coordinative carbonyl groups included in the ring. Silica-AM was similar to a cyclic monoamide we have reported because it exhibited adsorption to Pd(Ⅱ) and Re(VⅡ) in HNO3 of a particularly low concentration range. Silica-AM has an ether oxygen atom included in the ring as well. Considering the difference in the chemical structures of Silica-AM and other cyclic monoamide resins, it was suggested that oxygen atoms in the carbonyl group and in ether may be main contributors to Silica-AM's respective adsorptions to Pd(Ⅱ) and Re(VⅡ), and Mo(VI) and Zr(IV). Our results imply that the contribution of the two types of oxygen atoms to adsorption is more observable in an HCl system. The contribution of the ether oxygen atom to the adsorption of Pd(Ⅱ) was also suggested from our study on crystal prepared from 4-acetylmorpholine and palladium nitrate.