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1.
Improvement of primer adhesion to thermoplastic olefins (TPOs) by surface modification with a low‐temperature cascade arc discharge‐air plasmas was investigated. Air plasma with a low‐temperature cascade arc plasma torch can be used for improving the primer adhesion to TPOs. Tape‐adhesion tests (ASTM 3359‐92a method) demonstrated this improvement with a rating of “0” for untreated TPOs and “5” for air plasma‐modified TPOs at certain plasma conditions even for aging at 60 °C and 80% relative humidity for 5 days. The adhesion to primer for the soft and flexible kind of TPOs (ETA‐3041c and ETA‐3101) was easily enhanced. The adhesion to primer for the hard and brittle TPOs (ETA‐3183) needs to optimize the plasma conditions to pass the wet‐adhesion test using air plasmas. To relate the surface characteristics of air plasma‐modified TPOs to adhesion performance with primer, the wettability and polarity of TPOs were evaluated by the contact‐angle measurements of primer and deionized water to TPOs. TPO surface morphology was evaluated using scanning electron microscopy. The surface composition was characterized with electron spectroscopy for chemical analysis. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 623–637, 2002; DOI 10.1002/polb.10122  相似文献   

2.
聚氯乙烯表面共价键合肝素及抗凝血性的研究   总被引:8,自引:0,他引:8  
采用Ar等离子体引发聚乙二醇(PEG)在聚氯乙烯(PVC)表面固定化,进一步对固定PEG后的PVC进行肝素化处理,以改善PVC材料的抗凝血性能。探讨了PEG浓度对Ar等离子体固定化反应效果的影响。通过X射线光电子能谱(XPS)、衰减全反射红外光谱(ATR-FTIR)、扫描电镜(SEM)和接触角测定研究了固定PEG前后PVC的表面性能和表面形貌的变化。XPS分析证实肝素已成功地共价键合于PVC表面。采用体外凝血时间测定和血小板粘附实验对材料的抗凝血性能进行评价,结果表明,被修饰PVC材料的抗凝血性能显著提高。  相似文献   

3.
IrnmobilisedaIninoacylaseisanotablecatalystforthekineticresolutionofN-acetyl-D,L-aIninoacidsandquitealotofresearchworkhasbeeninvolvedonaminoacylase~bilisationswithitscarriers.lTheauthorshaverePortedthattheaIninosilicagelspreparedbyanlinProvedmethodwereeffechveforchymotryPsininunobilisahon,'l'butitwasnotproperforaIninoacylasetriobilisahon.InordertodevelopasahsfactorysurfacesmictUreofsilicagelsforaIninoacylasetriobilisation,tWokindsofreactivegrouPs,theN,N-diethylaIninogrouPandthehydroxygr…  相似文献   

4.
用N-溴代丁二酰亚胺的丙酮溶液在回流温度下对三甲硅基丙炔的均聚物和共聚物作了表面改性。XPS的研究表明,试样表面层中Br原子含量随溴化时间的增长而增加,C_(IS)谱变宽且产生来自C-O和C-Br结构的新谱线。红外光谱证明溴化反应产生CH_2Br结构。溴化使膜的气透性发生相应的变化,即α_(O_2/N_2)值增高,P_(O_2)值降低。  相似文献   

5.
The modification of surfaces by the deposition of a robust overlayer provides an excellent handle with which to tune the properties of a bulk substrate to those of interest. Such control over the surface properties becomes increasingly important with the continuing efforts at down‐sizing the active components in optoelectronic devices, and the corresponding increase in the surface area/volume ratio. Relevant properties to tune include the degree to which a surface is wetted by water or oil. Analogously, for biosensing applications there is an increasing interest in so‐called “romantic surfaces”: surfaces that repel all biological entities, apart from one, to which it binds strongly. Such systems require both long lasting and highly specific tuning of the surface properties. This Review presents one approach to obtain robust surface modifications of the surface of oxides, namely the covalent attachment of monolayers.  相似文献   

6.
Improvement of primer adhesion to thermoplastic olefins (TPOs) by methane plasma polymerization with a low‐temperature cascade arc discharge was investigated. Methane plasma with a low‐temperature cascade arc plasma torch can be used for improving the primer adhesion to TPOs. Tape‐adhesion tests (ASTM 3359‐92a method) demonstrated this improvement, with a rating of 0 for untreated TPOs and 5 for methane plasma‐polymerized TPOs at certain plasma conditions even for aging at 60 °C and 80% relative humidity for 5 days. The adhesion to primer for the soft, flexible TPOs (ETA‐3041c and ETA‐3101) was easily enhanced. The adhesion to primer for the hard and brittle TPOs (ETA‐3183) needs to optimize the plasma conditions to pass the dry‐ and wet‐adhesion test with methane plasmas. To relate the surface characteristics of methane plasma‐polymerized TPOs to adhesion performance with primer, the wettability and polarity of TPOs were evaluated by the contact‐angle measurements of primer and deionized water to TPOs. TPO surface morphology was evaluated with scanning electron microscopy. The surface composition was characterized with electron spectroscopy for chemical analysis. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 2004–2021, 2003  相似文献   

7.
Conductive polymer (poly(3,4‐ethylenedioxythiophene)‐poly(styrenesulfonate) (PEDOT:PSS) is an attractive platform for the design of flexible electronic, optoelectronic, and (bio)sensor devices. Practical application of PEDOT:PSS often requires an incorporation of specific molecules or moieties for tailoring of its physical–chemical properties. In this article, a method for covalent modification of PEDOT:PSS using arenediazonium tosylates was proposed. The procedure includes two steps: chemisorption of diazo‐cations on the PEDOT:PSS surface followed by thermal decomposition of the diazonium salt and the covalent bond formation. Structural and surface properties of the samples were evaluated by XPS, SEM‐EDX, AFM, goniometry, and a range of electric and optical measurements. The developed modification procedure enables tuning of the PEDOT:PSS surface properties such as conductivity and optical absorption. The possibility to introduce various organic functional groups (from hydrophilic to hydrophobic) and to create new groups for further functionalization makes the developed procedure multipurpose. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017 , 55, 378–387  相似文献   

8.
3-氨丙基三乙氧基硅烷(APTS)修饰的二氧化硅在生物化学、分析、催化、电子学等领域具有重要的应用前景。本文对近年来APTS修饰二氧化硅的研究进展进行了简要的概述,介绍了APTS修饰二氧化硅的典型方法和APTS修饰层的表征手段,探讨了不同修饰方法可控性及对所形成的APTS层结构及稳定性的影响。  相似文献   

9.
磁性SiO2载体的表面改性与纳米TiO2光催化剂的固载   总被引:3,自引:0,他引:3  
以Fe3O4米粒子为磁响应成分,制备了SiO2/Fe3O4磁性载体,采用回流热处理的方式对载体进行了表而改性.利用傅里叶变换红外和X-射线光电子能谱等手段对改性前后的载体进行分析.结果表明,载体改性后表面的Si-O-Si键数量明显减少,Si-OH的数量有所增加.以TiO2为探针催化剂,Procion染料为探针分子考察了载体的表面改性对催化剂固载量和光降解催化活性的影响,结果表明,改性后的载体明显提高了TiO2催化剂的固载量和降解Procion的催化活性.  相似文献   

10.
双(羟基)金属复合氧化物的表面改性   总被引:10,自引:0,他引:10  
水滑石;硬脂酸;湿法表面改性;双(羟基)金属复合氧化物的表面改性  相似文献   

11.
Despite heparin being the most widely used macromolecular drug, the design of small‐molecule ligands to modulate its effects has been hampered by the structural properties of this polyanionic polysaccharide. Now a dynamic covalent selection approach is used to identify a new ligand for heparin, assembled from extremely simple building blocks. The amplified molecule strongly binds to heparin (KD in the low μm range, ITC) by a combination of electrostatic, hydrogen bonding, and CH–π interactions as shown by NMR and molecular modeling. Moreover, this ligand reverts the inhibitory effect of heparin within an enzymatic cascade reaction related to blood coagulation. This study demonstrates the power of dynamic covalent chemistry for the discovery of new modulators of biologically relevant glycosaminoglycans.  相似文献   

12.
硅烷偶联剂表面修饰纳米氧化铝   总被引:10,自引:0,他引:10  
薛茹君  吴玉程 《应用化学》2007,24(11):1236-0
硅烷偶联剂KH570在乙醇溶剂中以酸水溶液为催化剂进行水解后对纳米氧化铝进行湿法表面修饰改性。用灼烧法测定了粉体表面偶联包覆率,以此为指标研究了KH570的水解条件及其对偶联效果的影响。结果表明,酸种类等水解条件对偶联效果有很大影响;适宜的偶联剂水解条件为:草酸作催化剂,调pH值为3~4,室温下水解1h。适宜的纳米氧化铝表面修饰条件为:偶联剂质量分数4.5%,在45℃偶联5.5h。经红外光谱(IR)分析,氧化铝的偶联修饰机理为:硅烷偶联剂与纳米氧化铝表面的羟基发生化学键合,从而实现纳米氧化铝的表面修饰改性。改性纳米氧化铝在有机相中的分散性和稳定性均得到了改善。  相似文献   

13.
聚丙烯微孔膜表面修饰的葡聚糖固定化研究   总被引:3,自引:0,他引:3  
糖以各种形式广泛存在于自然界,在人类的许多生理过程中起着不可或缺的重要作用.它具有优良的亲水性和生物特异性.研究表日月,将含糖单体接枝到聚丙烯微孔膜表面或通过共聚引入聚丙烯腈超滤膜,能显著提高常规高分子分离膜的抗污染能力和表面生物相容性,从而扩大其应用范围.  相似文献   

14.
Pt/CdS光催化剂表面修饰和表面结构   总被引:1,自引:0,他引:1  
张虎勤  金振声 《应用化学》1997,14(1):98-100
Pt/CdS光催化剂表面修饰和表面结构张虎勤陈开勋*金振声(西北大学化工系西安710069)(中国科学院兰州化学物理研究所兰州)关键词光催化剂,半导体,表面组成,表面修饰1996-05-20收稿,1996-09-28修回近年来对在Pt/CdS催化剂上...  相似文献   

15.
The chemical alteration of poly(tetrafluoroethylene) Teflon by vacuum ultraviolet radiation (VUV) (115–400 nm) has been examined with X‐ray photoelectron spectroscopy (XPS). The initial F/C atom ratio of 1.98 decreases to 1.65 after a 2‐h exposure. The F/C atom ratio is further reduced to a steady‐state value of 1.60 after a 74‐h exposure. The high‐resolution XPS C1s data indicate that new chemical states of carbon form as F is removed and that the relative amounts of these states depend on the F content of the near‐surface region. The states are most likely due to C bonded only to one F atom, C bonded only to other C atoms, and C that has lost a pair of electrons through the emission of F?. The exposure of the VUV‐damaged surface to research‐grade O2 results in the chemisorption of a very small amount of O, and this indicates that large quantities of reactive sites are not formed during the chemical erosion by VUV. Further exposure to VUV removes this chemisorbed oxygen. A comparison of the XPS data indicates that the mechanisms of chemical alteration by VUV radiation and hyperthermal (~5 eV) atomic oxygen are different, as expected, because the excitation sources are quite different. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 552–561, 2005  相似文献   

16.
碳纤维表面的液相氧化处理改性   总被引:7,自引:0,他引:7  
赵东宇  李滨耀 《应用化学》1997,14(4):114-116
碳纤维表面的液相氧化处理改性赵东宇*李滨耀余赋生(中国科学院长春应用化学研究所长春130022)关键词碳纤维,表面改性,氯酸钾,硫酸1996-10-24收稿,1997-05-29修回*现在黑龙江大学化学系(哈尔滨,150080)碳纤维具有高强、高模、...  相似文献   

17.
Poly(ethylene terephthalate) (PET) film surfaces were modified by argon (Ar), oxygen (O2), hydrogen (H2), nitrogen (N2), and ammonia (NH3) plasmas, and the plasma‐modified PET surfaces were investigated with scanning probe microscopy, contact‐angle measurements, and X‐ray photoelectron spectroscopy to characterize the surfaces. The exposure of the PET film surfaces to the plasmas led to the etching process on the surfaces and to changes in the topography of the surfaces. The etching rate and surface roughness were closely related to what kind of plasma was used and how high the radio frequency (RF) power was that was input into the plasmas. The etching rate was in the order of O2 plasma > H2 plasma > N2 plasma > Ar plasma > NH3 plasma, and the surface roughness was in the order of NH3 plasma > N2 plasma > H2 plasma > Ar plasma > O2 plasma. Heavy etching reactions did not always lead to large increases in the surface roughness. The plasmas also led to changes in the surface properties of the PET surfaces from hydrophobic to hydrophilic; and the contact angle of water on the surfaces decreased. Modification reactions occurring on the PET surfaces depended on what plasma had been used for the modification. The O2, Ar, H2, and N2 plasmas modified mainly CH2 or phenyl rings rather than ester groups in the PET polymer chains to form C? O groups. On the other hand, the NH3 plasma modified ester groups to form C? O groups. Aging effects of the plasma‐modified PET film surfaces continued as long as 15 days after the modification was finished. The aging effects were related to the movement of C?O groups in ester residues toward the topmost layer and to the movement of C? O groups away from the topmost layer. Such movement of the C?O groups could occur within at least 3 nm from the surface. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 3727–3740, 2004  相似文献   

18.
Polypropylene fabrics samples were surface functionalized under Ar and O2 RF plasma conditions. Survey and high resolution photoelectron spectroscopy and attenuated total reflectance FTIR comparative evaluation of virgin and plasma treated substrat surfaces, and their pentafluorophenyl hydrazine-derivatized correspondents, indicate that both Ar and O2-discharge treated PP surfaces undergo intense oxidation. C=O, O−C=O, and C−O linkages were identified on both inert and reactive gas plasma exposed surfaces. It was found that the relative surface atomic concentrations and the relative ratios of newly created functionalities are controlled by the external plasma parameters (RF power and treatment time). The oxidation of Ar-plasma treated surfaces has been related toex situ post plasma mechanisms. Dynamic contact angle measurements from unmodified and plasma exposed substrates demonstrated the presence of increased surface polarity, and its dependence on plasma parameters. AFM evaluations of plasma treated samples indicate the presence of rough surface morphologies. Paper based on the results presented during the workshop of the Engineering Research Center for Plasma-Aided Manufacturing held in Madison, Wisconsin, in Spring 1996.  相似文献   

19.
综述了聚烯烃类分离膜表面改性研究的主要进展,着重介绍了高能辐射接枝、光引发接枝、等离子体接枝、表面臭氧处理、以及超临界CO2状态下接枝等表面改性方法的特点,分析了改性后聚烯烃膜的性能,并对聚烯烃分离膜表面改性进行了展望。  相似文献   

20.
Several methods have been developed for grafting materials to the surface of polymers to alter their surface characteristics. This article reports a procedure for grafting poly(acrylic acid) (PAA) onto nylon 6,6 films via the naturally occurring amine end groups of nylon 6,6 using N‐hydroxy‐succinimide in conjunction with 1‐ethyl‐3‐ (3‐dimethylaminopropyl)carbodiimide hydrochloride (EDC) facilitated amidazation. Reaction conditions were investigated with respect to PAA molecular weight, activator concentrations, reaction temperature, and time. X‐ray photoelectron spectroscopy showed that surface coverage of more than 50% was consistently achieved for 250 kD PAA. The maximum grafting occurred at room temperature with a large excess of EDC with a reaction time of 30 min. The same level of grafting can be achieved using smaller amounts of EDC at 60 °C. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 719–728, 2002; DOI 10.1002/pola.10149  相似文献   

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