PET表面的碳氟等离子体处理改性层组分的变角XPS分析

采用CH₄/CF₄混合气体等离子体来处理PET表面.利用变角XPS研究改性后PET的表面改性层的组分随取样深度的变化.结果表明,碳氟混合气体等离子体在PET表面形成交联网络结构的改性层,改性层的化学组成随深度的变化不大;纯CF₄等离子体的改性层的化学组成不均匀,含氟基团主要分布在外面.不同混合气体等离子体在PET表面形成改性层的结构决定于CH₄的添加量.     

PET碳氟等离子体处理的表面动力学的研究(Ⅱ)──Wilhelmy吊片法的研究

通过Wilhelmy吊片法研究了CF₄/CH₄混合气体等离子体处理的PET浸水表面的动态行为.结果表明,处理后的PET浸水后表面增水性下降,这是由于表面含氟基团向体相的高速翻转及含氟链段向体相缓慢迁移的缘故.     

碳氟等离子体处理PET表面动力学的研究Ⅳ: 静、动态接触角 及变角XPS方法的 应用

利用静、动态接触角及变角XPS来研究碳氟(CF~4/CH~4)气体等离子体处理PET表面的浸水行为,结果表明碳氟等离子体处理的PET浸水后,其表面的憎水性下降。通过PET表面的接触角及F/C比的测定,计算出表面动力学衰减常数k,三种测试方法得到的k值都可以用来表征碳氟等离子体处理PET的表面动力学行为,其中混合气体的k值最小。从而证明混合气体等离子体的改性效果更有利于保持其表面的憎水性。     

碳氟等离子体处理PET表面动力学的研究Ⅳ: 静、动态接触角 及变角XPS方法的 应用

利用静、动态接触角及变角XPS来研究碳氟(CF~4/CH~4)气体等离子体处理PET表面的浸水行为,结果表明碳氟等离子体处理的PET浸水后,其表面的憎水性下降。通过PET表面的接触角及F/C比的测定,计算出表面动力学衰减常数k,三种测试方法得到的k值都可以用来表征碳氟等离子体处理PET的表面动力学行为,其中混合气体的k值最小。从而证明混合气体等离子体的改性效果更有利于保持其表面的憎水性。     

三氟甲基磺酰氟绝缘介质理化特性的分子动力学模拟

采用分子动力学模拟方法, 研究了新型绝缘介质三氟甲基磺酰氟(CF₃SO₂F)的理化特性, 为高压电气设备应用CF₃SO₂F替代SF₆气体提供了理论依据. 基于量子化学计算的分子结构、 内转动、 偶极矩和振动频率等优化设计了mPCFF力场模型, 计算了243~323 K温度范围内CF₃SO₂F的各种气-液相平衡性质(饱和蒸汽压、 密度、 热容、 蒸发焓和临界参数等)与关键输运特性(扩散系数、 介电常数、 黏度和热导率等)基础参数, 并考察了CF₃SO₂F与N₂或CO₂形成混合气体的理化特性. 通过对比SF₆以及C4/CO₂混合环保绝缘气体, 针对混合比、 液化温度、 扩散和热导等因素提出了CF₃SO₂F的电气设备应用建议.     

低温等离子体处理聚酯(PET)表面润湿性与表面结构的研究

研究了O₂、N₂、He、Ar、H₂和CH₄气体低温等离子体改性聚酯(PET)的表面润湿性与表面结构的关系.用已知表面张力的液体测定接触角,作Zisman曲线,求得试样的临界表面张力γ_c;并按扩展的Fowkes式计算试样的表面张力γ_s及其三组分值γ_s^a(色散力)、γ_s^c(偶极矩力)和γ(氢键力),发现经O₂、N₂、He和Ar等离子体短时间处理的聚酯表面自由能显著增大,表面润湿性增强,主要是聚酯表面张力的氢键力成分的贡献,X射线光电子能谱分析表明,这是由于聚酯表面含氧或含氮极性基团增加所致.     

全氟和多氟烷基磺酸的研究——Ⅵ.一些长链烷基醚磺酰氟的合成

末端氟烯烃R_FCF=CF₂[R_F=CF₃,Cl(CF₂)2～4,H(CF₂)₄,n-C₃F₇O]与四氟乙磺内酯、氟化钾和卤素在二乙二醇二甲醚中反应,得到长链烷基醚磺酰氟[R_FCFXCF₂OCF₂CF₂SO₂F](1,2_a,b～6_a,b)。烯烃结构和反应温度对磺酰氟的产率有一定影响。用三氟化钴处理R_FCFXCF₂OCF₂CF₂SO₂F(5b,2b,8,9)时,-CF₂SO₂F失SO₂而转化为-CF₃,形成多氟醚(R_FCFXCF₂OCF₂CF₃)7及10～12。控制反应温度,二磺酰氟13也可以失去一个SO₂为主而形成单磺酰氟15。     

全氟和多氟烷基磺酸的研究Ⅲ.1-氯-2-碘四氟乙烷与四氟乙烯的热调聚反应及其产物的化学转化

1-氯-2-碘四氟乙烷易与四氟乙烯进行热调聚反应,形成低分子量调聚物,Cl(CF₂CF₂)_nI(n=2～5),可以蒸馏分离.在低温下调聚物与普通格氏试剂反应得氯氟烷基卤化镁,再由它获得ω-氯代全氟烯烃-1Cl(CF₂CF₂)_nCF=CF₂(n=1,2,3)、ω-氯代全氟烷基醇Cl(CF₂CF₂)_nCR'R"OH(R'=CH₃,R"=H;R'=R"=CH₃;R'=R"=CF₃;n=2,3)及ω-氯代全氟烷基磺酰氯Cl(CF₂CF₂)_nSO₂Cl(n=2,3,4).通过ω-氯代全氟羧酸甲酯与甲基碘化镁的反应也得到ω-氯代全氟烷基醇Cl(CF₂CF₂).CF₂C(CH₃)₂OH(n=1,2).ω-氯代全氟烷基磺酸钾是稳定性很好的表面活性剂,可用作电镀镀铬中的铬雾抑制剂.     

偏氟乙烯与全卤代烷烃的调聚反应及其产物的研究

偏氟乙烯能够分别与四氯化碳和全氟叔丁基碘进行自由基的调聚反应,得到新型的调聚物CCl₃(CH₂CF₂)_nCl(n=1～6)和(CF₃)₃C(CH₂CF₂)_nI(n=1,2).调聚物的结构由核磁共振谱、红外光谱、元素分析和化学转化所证实.反应中亲电自由基·CCl₃与·C(CF₃)₃主要进攻偏氟乙烯上无氟碳原子,亦即在偏氟乙烯的自由基加成中,极性因素对加成方向起决定性作用.     

两种七氟醚自由基[(CF3)2C(·)OCH2F,(CF3)2CHOC(·)HF]与氧气反应及OH·再生机理的理论研究

温室气体七氟醚氧化降解可以产生两种反应活性截然不同的自由基，即（CF₃）₂C（·）OCH₂F与（CF₃）₂CHOC（·）HF.采用M06-2X/6-311++G（d，p）与CBS-Q理论方法研究了两种七氟醚自由基与氧气（O₂）反应的机理.与普通的烷基自由基+O₂的无垒复合反应不同，多氟取代的七氟醚自由基与O₂反应需经过1.3~1.8 kcal·mol^-1的势垒才能生成过氧自由基中间体RO₂·.虽然O₂更易于加成到富氟的自由基位点，但与贫氟自由基位点结合生成RO₂·放热更多，且随后的六中心氢迁移生成QOOH中间体需要克服更高的势垒.QOOH分解包括三种主要的OH·再生途径，即：分步解离、三体同步解离、四中心分子内S_N2反应.对于（CF₃）₂C（OC（·）HF）OOH，三条途径互为竞争；对于（CF₃）₂C（·）OC（HF）（OOH），分子内S_N2反应为OH·再生的主要途径，分步或三体同步解离则为次要机理.研究为阐明多氟取代基对大气中OH·循环的影响规律提供了理论依据.     

聚对苯二甲酸乙二酯膜的表面碳氟等离子体改性及XPS取样深度与接触角间的关系

高聚物界面的能量、结构等性质，对理论研究和实际应用都是极为重要的．因为许多聚合物材料都具有一个或多个界面的多相结构，这些界面的结构和强度等，显著地影响着这些多相材料的物理、力学性能等，而它们之间的关系，是一个极为复杂的问题，只有综合界面科学、流变学、...     

正、负离子碳氟-碳氢表面活性剂混合水溶液的表面活性

1　前言碳氟表面活性剂是目前所有表面活性剂中表面活性最高的一类 ,具有很多碳氢表面活性剂无法取代的特殊用途[1] 。但是碳氟表面活性剂由于合成困难 ,价格昂贵 ,实际应用受到限大限制。研究表明 ,通过碳氟表面活性剂与碳氢表面活性剂的复配 ,有可能减少碳氟表面活性剂的用量而保持其表面活性 [1] 。在所有表面活性剂混合体系中 ,正、负离子表面活性剂混合体系具有最强的协同效应 [2 ] 。但由于正、负离子表面活性剂混合溶液一般在很低浓度即形成沉淀 ,对碳氟表面活性剂更是如此。因此目前有关碳氟—碳氢混合表面活性剂的研究主要集中在同…     

碳氟-碳氢表面活性剂混合水溶液在油面上铺展

本文研究RfCONH(CH2)3N(C2H5)2CH3I/CnH2n 1,COONa及RfCOONa/CmH2m 1N(CH3)3Br(Rf=F[CF(CF3)CF2O]2CF(CF3);n=7,8.11,13;m=8,10,12)两类正，负离子碳氟－碳氢表面活性剂混合水溶液在油面上的铺展及对油面的密封性能。研究表明在碳氟表面活性剂中加入异电性碳氢表面活性剂可大大降低碳氟表面活性剂水溶液的铺展浓度，也可使一些因素表面张力较高而不能铺展的碳氟表面活性剂水溶液在油面上铺展。在碳氟表面活性剂中加入异电性碳氢表面活性剂可提高水膜对油面的密封性。若在混合表面活性剂中加入黄原胶，水膜的密封性能更好。     

On the importance of ions and ion-molecule reactions to plasma-surface interface reactions

Ions are known to be key players in many plasma processes, including anisotropic etching, film deposition and surface modification. The relationship between plasma ions, film properties, and surface interactions of other plasma species is not, however, well known. Using our Imaging of Radicals Interacting with Surfaces (IRIS) technique, along with plasma ion mass spectrometry (PI-MS), and surface analysis data, we have measured the effects of ion bombardment on the surface interactions of SiF2 in SiF4 plasmas and of CF2 in C3F8 and C4F8 plasmas. SiF2 is a known product of F-atom etching of Si, and CF2 has also been cited as a product of fluorocarbon etching of Si. With both molecules, we measure surface generation when the surface is bombarded by all the plasma species. Removal of ions from the plasma molecular beam results in a net decrease in surface generation for both molecules at all powers. Results in both systems are compared with the gas-phase ion-molecule reaction data of Armentrout and coworkers. Preliminary guided-ion beam mass spectrometry results taken in the Armentrout laboratories for the Ar+ + C3F8 reaction system are also presented.     

Neutralization of methyl cation via chemical reactions in low-energy ion-surface collisions with fluorocarbon and hydrocarbon self-assembled monolayer films

Low-energy ion-surface collisions of methyl cation at hydrocarbon and fluorocarbon self-assembled monolayer (SAM) surfaces produce extensive neutralization of CH3+. These experimental observations are reported together with the results obtained for ion-surface collisions with the molecular ions of benzene, styrene, 3-fluorobenzonitrile, 1,3,5-triazine, and ammonia on the same surfaces. For comparison, low-energy gas-phase collisions of CD3+ and 3-fluorobenzonitrile molecular ions with neutral n-butane reagent gas were conducted in a triple quadrupole (QQQ) instrument. Relevant MP2 6-31G*//MP2 6-31G* ab initio and thermochemical calculations provide further insight in the neutralization mechanisms of methyl cation. The data suggest that neutralization of methyl cation with hydrocarbon and fluorocarbon SAMs occurs by concerted chemical reactions, i.e., that neutralization of the projectile occurs not only by a direct electron transfer from the surface but also by formation of a neutral molecule. The calculations indicate that the following products can be formed by exothermic processes and without appreciable activation energy: CH4 (formal hydride ion addition) and C2H6 (formal methyl anion addition) from a hydrocarbon surface and CH3F (formal fluoride addition) from a fluorocarbon surface. The results also demonstrate that, in some cases, simple thermochemical calculations cannot be used to predict the energy profiles because relatively large activation energies can be associated with exothermic reactions, as was found for the formation of CH3CF3 (formal addition of trifluoromethyl anion).     

疏水-亲脂作用对反应性的影响III:环糊精对碳氟表面活性剂的熵驱动包结以及亲脂作用对形成糖淀粉型包结物的贡献

用表面张力-浓度曲线法系统地研究了环糊精(CD)和羧甲基糖淀粉钠(Na-CMA)与H(CF2)12CO2K(1),Cl(CF2)nCH2CH2N^+(CH3)3I^-[n=8(3),10(5)]和相应的碳氢表面活性剂(2,4和6)的相互作用.由于几何尺寸的限制,碳氟表面活性剂不能与α-CD形成包结络合物,但3与β-CD形成的包结络合物的稳定性远大于相应的碳氢受物4、3与β-CD的相互作用是熵驱动过程,而C12H25N^+(CH3)3I^-(6)则是焓有利的.与具有"预组织化"内穴的CD不同,糖淀粉的包结是与大分子从线团到螺旋构象变化的协同过程,由于缺乏宿主-受物间的亲脂相互作用,Na-CMA不能与所有的碳氟受物形成包结络合物.     

Surface characterization of plasma‐modified poly(ethylene terephthalate) film surfaces

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     

Surface reactivity and energetics of CH radicals during plasma deposition of hydrogenated diamondlike carbon films

The surface reactivity of CH radicals was measured during plasma deposition of hydrogenated diamondlike carbon (DLC) films using the imaging of radicals interacting with surfaces (IRIS) method. In this technique, spatially resolved laser-induced fluorescence (LIF) is used to determine surface reactivity, R, of plasma species. The measured reactivity of CH is near unity and shows no dependence on the applied rf power (P), argon fraction, substrate temperature, or substrate bias. Kinetic translational temperatures, (T), of CH in the molecular beam were also measured. Modeling of the kinetic data yields ThetaT(CH) values of approximately 2200-2500 K and 1600-1700 K for CH4/Ar plasmas at pressures of 50 and 110 mTorr, respectively, with no clear dependence on the argon fraction (at P = 100 W). The average ThetaT(CH) does, however, change with P, (T) = approximately 2050-9050 K, over the range P = 180-20 W. These results indicate that ThetaT(CH) is associated with the electron temperature in the plasma. The rotational temperature, (R), determined from the CH rotational excitation spectrum is approximately 1450 K with no clear dependence on P or the Ar fraction in the feed. The difference between ThetaT(CH) and ThetaR(CH) can be explained by the different relaxation rates after the dissociation of CH4 by electron impact.