低温等离子体对超高分子聚乙烯纤维表面改性研究

介绍了低温等离子放电技术的概念、原理、实施方法及其在超高分子量聚乙烯（UHMWPE）纤维表面改性方面的应用。综述了国内外低温等离子体对UHMWPE纤维表面改性的最新研究成果,阐述了气体等离子体种类、处理功率和处理时间等因素对UHMWPE纤维表面改性效果的影响机理,以及低温等离子设备对UHMWPE纤维表面改性连续化的初步...     

低温等离子体作用下亮氨酸转化路径的密度泛函理论研究

目前低温等离子体技术在处理固体废弃物方面已得到广泛关注,本研究基于密度泛函理论(DFT),在B3LYP/6-31G (d,p)的水平上模拟计算了污泥中蛋白质模型化合物亮氨酸(LEU)在低温等离子体中的转化路径,包括脱氨优先机理、脱羧优先机理、其余C-C键断裂优先机理等七条主要路径。结果表明,亮氨酸易脱除氨基、羧基生成C_5H_(10),再进一步分解成小分子烃。产物CO_2来自羧基;生成CO的反应势垒相对较高,但CO_2易在等离子体中被电离成CO从而提高CO的产量;小自由基的相互结合及其他小分子的分解生成CH4和H_2。所有路径所需的能量均在低温等离子体高能电子能量的最大值范围内。     

低温等离子体惰化色谱硅藻土担体

低温等离子体具有很强的激发化学反应和处理表面的能力。国外已用于色谱填料表面改性,我们也曾用作制备色谱键合固定相。 利用低温等离子体中的自由基,可以在气相中实现分子链的增长、转移、复合及终止等基元反应、形成惰性聚合物薄膜附着在硅藻土表面,或自由基与硅藻土表面的活性点(如硅醇基)结合,以覆盖其表面的活性点及堵塞其不利于传质的毛细微孔,达到惰化硅藻土的目的。     

高性能纤维表面改性及其双马树脂基复合材料界面

采用电感耦合射频等离子体(ICP)和介质阻挡放电(DBD)低温等离子体对高性能连续纤维表面进行改性,分别采用X光电子能谱(XPS)、原子力显微镜(AFM)和动态接触角测定仪(DCA)等分析测试手段系统地研究了等离子体处理时间、放电功率、放电气压等对连续碳纤维、聚苯并二噁唑(PBO)纤维改性处理前后,纤维表面状态、表面组成、表面形貌、浸润性能的变化规律以及经等离子体处理前后纤维增强双马树脂基复合材料界面结构与性能的影响关系及变化规律、复合材料界面粘结和破坏机理.研究结果表明,经过等离子体处理后,纤维表面接枝上了大量的含羧基、羟基等极性官能团,表面粗糙度增加,表面自由能增加,纤维浸润性能得到明显改善,导致纤维与双马树脂基体界面层间剪切强度(ILSS)明显提高,复合材料的破坏模式由未处理的界面脱粘破坏转变为等离子体处理后的树脂基体破坏.最后,对纤维表面时效性及其对纤维增强双马树脂基复合材料界面性能的影响关系也进行了论述.     

等离子体引发甲基丙烯酸缩水甘油酯在聚丙烯膜上的接枝反应及肝素的固定化

等离子体引发甲基丙烯酸缩水甘油酯在聚丙烯膜上的接枝反应及肝素的固定化李刚孙求实後晓淮（中国科学院化学研究所北京１０００８０）关键词甲基丙烯酸缩水甘油酯，肝素，等离子体，等离子体引发接枝聚合利用等离子体表面处理能使高分子材料表面生成自由基，这已被许多...     

木粉/聚乙烯复合材料的等离子体表面处理——等离子体处理时间对复合材料表面特性的影响

为改善木粉/聚乙烯复合材料的表面粘接性,实现木粉/聚乙烯复合材料的无缝连接,利用低温等离子体处理技术,对木粉/聚乙烯复合材料进行了表面处理.采用接触角测试、傅立叶变换红外光谱分析(FTIR)以及X射线光电子能谱分析(XPS)研究了等离子体处理前后复合材料表面性能的变化.试验结果表明,经等离子体处理后,复合材料表面的接触角减小,表面润湿性得以改善;FTIR分析结果表明,经等离子体处理后,复合材料表面有—OH、—C=O和—O—C=O基团生成;XPS分析表明,经等离子体处理后,复合材料表面含氧基团的含量增加,在较短的时间内表面氧元素含量增加会达到平衡,且生成大量的—O—C=O基团。     

等离子体辐照的聚乙烯表面接枝交联共聚合

聚合物利用低温等离子体预辐照进行表面接枝共聚合已有报道.此方法的优点是接枝层被限制在聚合物表面,辐照过程对基材本体性质无影响,且整个过程对环境无污染. 用等离子体使聚合物表面产生自由基,不需要表面具有不饱和键或特殊官能团,因而适用于任何聚合物,甚至于一些无机物如玻璃等.利用等离子辐照后暴露于空气的聚合物表面上生成的过氧自由基或过氧化物进行接枝反应,一般接枝量不大.本工作中,我们自己设计了反应器,以超高分子量聚乙烯(UHMWPE)为基材,以甲基丙烯酸甲酯(MMA)为接枝单体,在无氧条件下利用等离子体辐照产生的表面自由基进行了接枝聚合,产物接枝量高达10％.还用顺磁共振技术对表面自由基性质及其在接枝过程中的行为进行了跟踪研究.     

提高PBO纤维/环氧树脂复合材料界面结合的研究

本文采用表面化学蚀刻与溶胀法结合、化学偶联法与氩气低温等离子体表面处理技术结合的方法对聚苯撑苯并二。唑（PBO）纤维进行表面改性。探讨了不同改性方法对纤维表面性能的影响。同时，采用FTIR和SEM等方法对处理前后纤维表面化学结构及形态进行了表征。     

空气介质阻挡放电对超高分子量聚乙烯纤维表面性能及粘结力的影响研究

利用空气介质阻挡放电(DBD)等离子体对超高分子量聚乙烯(UHMWPE)纤维进行表面改性处理研究以提高纤维表面的润湿和粘结性能.分别研究了等离子体处理时间及电压对UHMWPE纤维拉伸断裂强力、接触角、表面形貌、表面化学成分和粘结性能等的影响规律.SEM分析结果表明,空气DBD等离子体处理后UHMWPE纤维表面出现垂直于纤维轴向分布的凹坑和裂纹,使得纤维表面粗糙度显著增加.XPS分析表明空气DBD处理后纤维表面碳元素含量显著下降;同时氧元素和氮元素的含量均较处理前增加,但氧元素含量增加的幅度显著高于氮元素.XPS分峰结果表明等离子体处理后UHMWPE纤维纤维表面C—O/C—N基团含量显著增加,同时出现了C O和O—C O这2种新的含氧官能团.同时,接触角及和与环氧树脂之间的界面剪切力(IFSS)测试结果表明DBD等离子体处理后UHMWPE纤维表面润湿性能和粘结力均产生显著提高,且随着等离子体处理时间或电压的增加,UHMWPE纤维的表面润湿性能和粘结力均呈现先上升后下降的趋势.空气DBD等离子体处理对UHMWPE纤维的力学性能影响较小,当处理电压低于200 V,处理时间小于100 s,纤维强力下降比率小于5.2%.     

低温等离子体对聚合物多孔膜的亲水化改性

综述了低温等离子体在聚合物多孔膜表面亲水化改性领域的研究与应用进展。在简要介绍等离子体技术的原理、方法的基础上,讨论了Ar、He、O2、N2、CO2、H2O、NH2和SO2等非反应性和反应性气体的等离子体表面处理,烷基醇、烷基胺、烯丙基醇和烯丙基胺等饱和及不饱和单体的等离子体沉积聚合,以及烯类单体的等离子体引发的接枝聚合等等离子体方法,对膜表面和膜孔壁的化学组成和形态结构、膜亲水性的获得及其时效性、膜水通量和蛋白质抗污染性等方面的影响。     

Organic–inorganic hybrid silica film coated for improving resistance to capsicum oil on natural substances through sol–gel route

This study concerns the organic–inorganic hybrid coating of silica sol based on dyed cotton, silk and wool fabrics in order to increase the repellence to capsicum oil via adding methyltriethoxysilane, octyltriethoxysilane, hexadec-ltrimethoxysilane or tridecafluorooctyltriethoxysilane (FAS) in the inorganic silica sol. The dyed cotton fabric treated with hybrid silica sol doped with FAS (F-silica sol, FAS 4 %) presents oil-repellent capability, and the contact angles of capsicum oil on the treated cotton, silk and wool fabrics are 98.5°, 111.59° and 122.15°, respectively. A high FAS concentration (20 %) can improve the oil-repellent ability to 5 grades comparing to the untreated fabrics. The color strengths (K/S) of the coated fabrics change slightly, while the maximum absorption wavelengths of the coated fabrics are the same as the untreated fabrics. Although the drape coefficient of cotton fabric is increased to 54 % from 39 % after coated with F-silica sol, the effect is not significant. Compared to the weight gain rate of untreated cotton, silk and wool samples (1.89, 1.23 and 2.38 %), the weight gain rate of the cotton, silk and wool samples coated with F-silica sol are 6.99, 4.76 and 7.69 %, respectively. The calculated sol–gel weight gains (5.10, 3.53 and 5.31 %) of coated fabrics indicate that the silica coating is subsistent on the fiber surfaces.     

氯氟烃的选择性还原及其在合成含氟麻醉剂中的应用

本文阐述了用过硫酸铵/醋酸氨[ (NH~4)~2S~2O~8/HCOONH~4 ]和过硫酸铵/磷酸二氢钠·水[ (NH~4)~2S~2O~8/NaH~2PO~2·H~2O ]选择性还原1,1,3,4-四氯全氟丁烷CF~2ClCFClCF~2CFCl~2。介绍了应用这类选择性还原反应合成含氟吸入性麻醉剂CHF~2OCF~2CHClF (Enflurane)和CHF~2OCHClCF~3 (Isoflurane)。     

Colorimetric studies of heterocyclic monoazo reactive dyes and their dyeing applications on cotton,silk, and wool fibers

Heterocyclic quinazolinone-based hot brand monoazo reactive dyes were obtained by diazotization of 3-(4-aminophenyl)-2-phenylquinazolin-4(3H)-one and coupling with a variety of cyanurated coupling components. All the heterocyclic hot brand monoazo reactive dyes were characterized by elemental analysis (C, H, N) and by use of spectroscopic techniques (FT-IR, UV–visible, ¹H NMR). Their performance as reactive dyes was assessed on silk, wool, and cotton fabrics. The dyes were found to give a variety of color shades with very good depth and uniformity on the fibers. The fastness of all the dyes on the fibers was moderate to excellent. Colorimetric data (L*, a*, b*, C*, H*, and K/S) of the synthesized dyes were also studied in detail.     

Influence of Neem oil pretreatment on the dyeing and antimicrobial properties of wool and silk fibers with some natural dyes

Wool and silk fibers pretreated with neem oil and dyed with chlorophyll, saffron red and yellow natural dyes using economic methods such as microwave heating and ultrasonic energy. The effect of neem oil concentrations on color strength (K/S) was measured. The results indicated that, wool and silk fibers pretreated with neem oil recorded higher color strength values than the untreated fibers. Fastness properties and the color yield of the dyes under investigation on wool and silk fibers were evaluated. The results indicated that, color fastness to rubbing, washing and perspiration of all dyes are excellent to good and are approximately the same in microwave and ultrasonic method. The antimicrobial activity against bacteria and fungi were tested, and the results indicated that the samples pretreated exhibited higher inhibition percent than the untreated fibers. The morphologies structure of the untreated and treated wool fibers were examined by scanning electron microscopy (SEM). The untreated samples have a rough surface. The pretreated samples of wool fibers were swelling compared to the untreated fibers .The diameter of the fibers increased and have smooth and even surfaces. The changes in the surface morphology due to the effect of active ingredients of treatment with neem oil. This behavior as swelling and increase in diameter of the fibers leads to high penetration of the dyes in the fibers.     

CF3I在强红外场下的多光子解离

本文用TEA CO_2激光9.6R(14)支作激发光源, 富里叶变换红外光谱仪作分析手段, NO, O_2作CF_3自由基的捕捉剂, 研究了CF_3I红外多光子解离的动力学。实验发现, O_2和NO均可用来捕捉CF_3I的红外光解产物CF_3自由基。从对CF_3I的红外多光子解离率与外加气体压力的变化关系的研究, 以及CF_3I红外多光子吸收的测量, 揭示出该分子在受红外激光激发时, 具有小分子的特性。同时也观察到外加气体对早期瓶颈效应的消除。在无碰撞及早期瓶颈效应可忽略状态下, 用能量间隔主方程对多光子解离率与激光能量密度的变化关系作了拟合, 得出了与实验比较一致的结果。     

多氟烯烃和炔烃的钯催化氢化

本文报道Pd/Al_2O_3(1%)催化剂催化氢化CF_3CCl=CClCF_3,CF_3CCI==CHCF_3和CF_3C=CCF_3等多氟烯烃和炔烃的结果。经1~H和(19)~F核磁共振、质谱、红外等分析,证明了用制备色谱分离后的氢化产物主要成份的结构。前二者的氢化产物中主要是CF_3CH_2CH_2CF_3和CF_3CH_2CHClCF_3的混合物,而CF_3C=CCF_3氢化后只生成CF_3CH_2CH_2CF_3。     

二氧化碳激光引发2-氯-1,1,1,2-四氟乙烷反应

本文研究了用TEA-CO_2激光和CW-CO_2激光以SF_6作为敏化剂引发CF_3CFHCl的反应。分析了CF_3CFHCl以及添加清除剂Cl_2,Br_2,O_2,的光解产物。结果表明CF_3CF:是初级产物,它很易重排成为CF_2—CF_2,或转化成CF_3CF—CF_2。在Cl_2或Br_2存在时,可生成CF_3CFCl_2或CF_3CFBr_2。此外,还讨论了反应机制。     

Co_3O_4 modified Ag/g-C_3N_4 composite as a bifunctional cathode for lithium-oxygen battery

Rechargeable lithium-oxygen(Li-O_2)batteries have appeal to enormous attention because they demonstrate higher energy density than the state-of-the-art Li-ion batteries.Whereas,their practical application is impeded by several challenging problems,such as the low energy round trip efficiencies and the insufficient cycle life,due to the cathode passivation caused by the accumulation of discharge products.Developing efficient catalyst for oxygen reduction and evolution reactions is effective to reduce the overpotentials in Li-O_2cells.In our work,we report a Co_3O_4modified Ag/g-C_3N_4nanocomposite as a bifunctional cathode catalyst for Li-O_2cells.The g-C_3N_4substrate prevents the accumulation of Ag and Co_3O_4nanoparticles and the presence of Ag NPs improves the surface area of g-C_3N_4and electronic conductivity,significantly improving the oxygen reduction/evolution capabilities of Co_3O_4.Due to a synergetic effect,the Ag/g-C_3N_4/Co_3O_4nanocomposite demonstrates a higher catalytic activity than each individual constituent of Co_3O_4or Ag/g-C_3N_4for the ORR/OER on as catalysts in Li-O_2cells.As a result,the Ag/gC_3N_4/Co_3O_4composite shows impressive electrochemical performance in a Li-O_2battery,including high discharge capacity,small gap between charge and discharge potential,and high cycling stability.     

Production,Partial Characterization,and Use of a Red Biochrome Produced by <Emphasis Type="Italic">Serratia sakuensis</Emphasis> subsp. nov Strain KRED for Dyeing Natural Fibers

We have described a novel red biochrome, 514 Da in size, produced by solid-state cultivation of a bacterial isolate obtained from garden soil. The growth requirements of the isolate, the chemical characteristics of the biochrome produced, and the application of the biochrome in dying of silk, wool, and cotton fabrics have been studied. The biochrome obtained after 52 h of incubation and having a λ _max of 535 nm was used for dyeing the fabrics. We found that silk, wool, and cotton fabrics dyed with this new natural red compound have high color strength values and dye uptake along with good color fastness as well as antibacterial activity.     

Theoretical investigation of some O-nitrosyl carboxylate biologic molecules �� A natural bond orbital study

Theoretical study of several O-nitrosyl carboxylate compounds have been performed using quantum computational ab initio RHF and density functional B3LYP and B3PW91 methods with 6-31G** basis set. Geometries obtained from DFT calculations were used to perform the natural bond orbital (NBO) analysis. It is noted that weakness in the O₃-N₂ bond is due to $ n_{O_1 } \to \sigma _{O_3 - N_2 }^* $ n_{O_1 } \to \sigma _{O_3 - N_2 }^* delocalization and is responsible for the longer O₃-N₂ bond lengths in O-nitrosyl carboxylate compounds. It is also noted that decreased occupancy of the localized $ \sigma _{O_3 - N_2 } $ \sigma _{O_3 - N_2 } orbital in the idealized Lewis structure, or increased occupancy of $ \sigma _{O_3 - N_2 }^* $ \sigma _{O_3 - N_2 }^* of the non-Lewis orbital, and their subsequent impact on molecular stability and geometry (bond lengths) are related with the resulting p character of the corresponding sulfur natural hybrid orbital (NHO) of $ \sigma _{O_3 - N_2 } $ \sigma _{O_3 - N_2 } bond orbital. In addition, the charge transfer energy decreases with the increase of the Hammett constants of subsitutent groups.