Glow characterization in direct current plasma polymerization of trimethylsilane

Plasma polymerization of trimethylsilane (TMS) was carried out in a direct current (dc) glow discharge and was investigated by optical photography and plasma diagnostic techniques including optical emission spectroscopy and residual gas analysis. The nature of the glow formed in TMS discharge, which deposited plasma polymers, was significantly different from that of a simple gas such as Ar. In an Ar discharge, the dominant glow was the well known negative glow, which developed at a distinctive distance from the cathode, whereas the cathode surface remained in the dark space. In strong contrast to this situation, in TMS dc discharge the dominant or primary glow was the cathode glow, which appeared at the cathode surface. At a similar location where the Ar negative glow appeared, a very feeble glow as a secondary glow was also observed in TMS glow discharge. The deposition results and plasma diagnosis data evidently indicated that in TMS glow discharge, the cathode glow resulted from the low‐energy electron‐impact dissociation of TMS molecules that creates polymerizable species, but the negative glow was related to nonpolymerizable species such as hydrogen atoms and molecules. In this article, the cathode glow formed in glow discharges of organic compounds was designated as the dissociation glow according to its underlying plasma reactions. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 1042–1052, 2004     

Creation of Polymerizable Species in Plasma Polymerization

Plasma polymerization of trimethylsilane (TMS) was carried out and investigated in a direct current (dc) glow discharge. The formation of TMS plasma glow was carefully examined with optical photography as compared with an Ar dc glow discharge. It was found that there exists a significant difference in the nature of glow and how the glow is created in TMS glow discharge, which polymerizes or causes deposition, and that of monatomic gas such as Ar, which does not polymerize or deposit. In dc Ar discharge, the negative glow, which is the most luminous zone in the discharge, develops in a distinctive distance away from the cathode surface, and the cathode remains in the dark space. In a strong contrast to this situation, in TMS dc discharge, the primary glow that is termed as cathode-glow in this paper appears at cathode surface, while a much weaker negative glow as a secondary glow was observed at the similar location to where the Ar negative glow appears. The deposition results of plasma polymers and gas phase composition data of TMS in a closed reactor acquired by ellipsometry and residual gas analyzer (RGA) measurements clearly indicated that the cathode-glow in TMS glow discharge is mainly associated with chemically reactive species that would polymerize or form deposition, but the negative glow is related to species from simple gases that would not polymerize or deposit. Based on the glow location with respect to the cathode, it was deduced that the cathode-glow is due to photon emitting species created by molecular dissociation of the monomer that is caused by low energy electrons emanating from the cathode surface. The negative glow is due to the ionization and the formation of excited neutrals of fragmented atoms caused by high-energy electrons. Polymerizable species that would cause deposition of material (plasma polymers) are created mainly by the fragmentation of monomer molecules by low energy electrons, but not by electron-impact ionization of the monomer.     

Wachstum dünner Fluorkohlenstoffschichten auf der Anode einer Glühkathodenentladung

The polymerization of tetrafluorethylene on the anode of a hot glow discharge has been investigated. Rates of polymer deposition have been measured as a function of monomer pressure, discharge current density, and electrode surface temperature. A mechanism of polymer formation is suggested. The results are different from those obtained by polymerization of the same monomer in a glow discharge. It is concluded that negative ions have a great influence on mechanism of polymer formation. Additionally, monomer molecules adsorbed at the electrode are polymerized by electron bombardment.     

含氮、硫单体等离子体聚合过程中气相组分分析

报导了用ＧＣ－ＭＳ和ＩＲ对含氮，硫单体等离子体聚合过程中气相组分的分析，根据分析结果探讨了该类单体等离子体聚合机理。     

甲苯二异氰酸酯的低温等离子聚合

辉光放电等离子聚合技术已逐步得到发展和应用,Harada报导,TDI的等离子聚合薄膜具有极为优良的耐磨性能。本工作报道不同进气和电感位置对TDI等离子聚合的影响,并结合红外光谱和元素分析对聚合产物进行了结构分析。     

丙醛的等离子体聚合以及聚合物的结构与性质初探

应用外部电容耦合式等离子体聚合方法,制得了丙醛聚合物,研究了不同的等离子体条件对丙醛的聚合行为的影响。通过元素分析、红外光谱分析、色谱-质谱联合分析、X-射线衍射、润湿性测定等手段研完发现,聚合物为无定形交联结构,表面能为41—45达因/厘米。     

α-蒎烯等离子体聚合及其聚合物结构研究

本文应用外部电容耦合式聚合装置,研究了α—蒎烯等离子体聚合规律。通过元素分析,裂解色谱-质谱、红外光谱和接触角测定等方法测定了聚合物的结构和性能。     

Plasma polymerization of styrene with controlled particle energy

A new type of reactor for plasma polymerization was developed in order to achieve an effective control of styrene polymerization process. Electrons and ions were extracted from the radio frequency (rf) glow discharge region to the downstream region to generate plasma polymerization. The energy of extracted ionized particles was controlled by the bias voltage of a screen grid unit. Deposited polymer thin films were analyzed by X-ray photoelectron spectroscopy (XPS) and infrared (IR) spectroscopy. The result showed that the polarity and energy of the extracted particles had considerable effect on the deposition rate and structure of the deposited films. At each bias polarity there was a maximum deposition rate vs. voltage magnitude, and the maximum at the positive voltage was higher. In addition, the bulk aromaticity of the film deposited at the negative bias was lower than at the positive bias; the surface aromaticity of the films was much higher than that of the films prepared by usual rf discharge. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1265–1270, 1998     

四氟乙烯等离子体聚合的研究——Ⅱ.四氟乙烯等离子体聚合的反应历程

<正> 在前报,已应用ESCA等方法研究了辉光区和非辉光区等离子体聚四氟乙烯(PPTFE)淀积膜的结构。鉴于等离子体聚合反应的复杂性,前人对等离子体聚合反应机理争论较大,争论焦点集中在反应的活性种是离子还是自由基以及反应的地点这两个问题上,本工作在前报工作的基础上,进一步应用ESR检测出等离子体气体流出物的冷凝物中含有大量自由基,为证实等离子体聚合的自由基反应历程提供了新依据;还采用GC-MS表征了气体冷凝物的结构。比仅用MS分析气相产物有较大优点。综合这些实验结果,为推测四氟乙烯等离子体聚合反应历程奠定了一定的基础。     

Glow Discharge Induced Graft Polymerization of Nonvolatile Monomers on Wool

Nonvolatile monomers were grafted to wool by exposure to rf glow discharge under vacuum. The amount of grafting was limited to an average of 2 to 5% weight uptake. With increasing impregnation the amount of graft decreased, and mostly extractable homopolymers formed. Increasing the intensity of the glow discharge above a certain level is also detrimental because at this point the rate of degradation exceeds the rate of polymerization.     

Effect of Glow Discharge Conditions on Structure and Thermal Properties of Polysilazane Thin Films

Polysilazane thin films were prepared by glow discharge polymerization of hexamethylcyclotrisilazane in mixture with various gases: argon, nitrogen, hydrogen and ammonia. The effect of gas type on thermal stability and chemical structure of glow discharge polysilazane was studied. Thermo-gravimetric measurements performed within a temperature range of 20–1000° C, showed that the best thermal stability was exhibited by polysilazane prepared at the presence of ammonia in the reaction mixture. IR analyses data revealed that polymers prepared from mixture with ammonia or hydrogen contained more Si-H groups than those obtained with argon or nitrogen. It proves that in the presence of ammonia or hydrogen, greater monomer fragmentation through Si-C bonds cleavage takes place. More detailed investigations were carried out for polysilazanes prepared in mixture with ammonia. It was found that thermal stability as well as chemical structure of polymer depend strongly on polymerization conditions, i. e., ammonia contents in the reaction mixture, deposition time, discharge current density. Thermal stability of polysilazane improved with the increase in deposition time and current density. Increasing these parameters caused also the Si-NH-Si bonds content in the polymer to grow. The results prove that ammonia is a reactive comonomer and that the polymerization of hexamethylcyclotrisilazane at the presence of this gas may proceed through the formation of Si-NH-Si bonds.     

二甲基苯胺等离子体聚合及聚合物结构与性能的研究

应用外部电容耦合式等离子体聚合装置，研究了二甲基苯胺等离子体聚合规律，找到了最佳的聚合条件。通过热失重，红外光谱、Ｘ－射线衍射、电子衍射和接触角测定等，研究聚合物结构与性能。电导率测定表明二甲基苯胺等离子体聚合物具有半导体性质。     

等离子体聚四氟乙烯的ESCA表征

<正> 研究碳氟化合物的等离子体聚合膜结构,对开拓新的应用领域及等离子体化学的基础研究均有实际意义。Pender和Nakajima用内极装置合成了全氟化合物的等离子体聚合膜,但在C_(15)区的ESCA谱的归属方面存在分歧。本文采用外部电容耦合式装置合成了等离子体聚四氟乙烯(PPTFE)膜,应用ESCA表征了PPTFE的结构,并运用模型化合物的理论计算结果,总结出计算结合能位移的经验式,为C_(15)区的ESCA谱的归     

吡咯等离子体聚合及聚合物结构的研究

本文应用外部电容耦合式聚合装置,研究了吡咯等离子体聚合规律,找到了较好的聚合条件。通过元素分析、红外光谱等研究了聚合物的结构,电导率测定表明等离子体聚吡咯具有半导体性质。     

Structure and tribological properties of Cu–PU–PTFE composite coatings prepared by low‐energy electron beam dispersion with glow discharge

Polytetrafluoroethylene (PTFE) composite coatings doped copper acetate and polyurethane (PU) were prepared on rubber substrate by low‐energy electron beam dispersion technique. The effects of dopant and glow discharge treatment on the surface morphology, structure and tribological properties of the coatings were investigated. The results showed that Cu–PTFE composite coatings form uniform surface and dense column structure with spherical aggregations under glow discharge treatment. PU coating shows the large size of protuberance structure but PU–PTFE coating presents spherical structure. Both of the coatings become relative dense and smooth after discharge treatment, and Cu–PU–PTFE composite coatings possess a smoother surface and lower polar component of surface energy. Cu doping weakens the crystallinity and ordering degree of composite coatings, but glow discharge increases the ordering degree and branched structure of C―H groups. Friction experiment indicated that Cu fails to improve the wear resistance of PTFE coatings but glow discharge treatment can do it. Cu–PU–PTFE coatings after discharge treatment have the higher wear resistance and lower coefficient of friction. Copyright © 2016 John Wiley & Sons, Ltd.     

Critical evaluation of conditions of plasma polymerization

Under conditions of plasma polymerization, we are dealing with the “reactive” or “self-exhausting” rather than the “nonreactive” or “non-self-exhausting” gas phase (plasma). Therefore, many parameters that define the gas phase, such as system pressure and monomer flow rate, which are measured in the nonplasma state (before glow discharge is initiated), do not apply to a steady state of plasma, the conditions under which most of the studies on plasma polymerization are carried out. Consequently, information based on: (1) the polymer deposition rate measured at a fixed flow rate and discharge power, (2) the dependence of deposition rate on flow rate at fixed discharge power, or (3) the dependence of deposition rate on discharge power at fixed flow rate, does not provide meaningful data that can be used to compare the characteristic nature of various organic compounds in plasma polymerization. The significance and true meaning of experimental parameters applicable to conditions of plasma polymerization are discussed. The most important feature is that plasma polymerizations of various organic compounds should be compared at comparable levels of composite discharge power parameter W/FM, where W is discharge power, F is the monomer flow rate (given in moles), and M is the molecular weight of a monomer.     

醛类的等离子体聚合Ⅰ.丁醛等离子体聚合及聚合物结构与性能

应用外部电容耦合式等离子体聚合方法,首次得到了丁醛聚合物,研究了其聚合规律,找到了较好的聚合条件。通过元素分析和红外光谱分析,证实丁醛等离子体聚合物为交联结构;电子衍射分析和X-射线衍射分析发现聚合物中存在部分结晶,而且部分以单晶形式存在;表面能测定表明丁醛等离子体聚合物为疏水性。并初步探讨了反应机理。     

POLYMERIZATION OF OCTAFLUOROCYCLOBUTANE IN GLOW DISCHARGE Ⅱ. ESCA AND IR CHARACTERIZATION OF POLYMER STRUCTURE*

In a capacitively coupled discharge with external electrodes, He, H_2, N_2 or Ar were used as plasmagas, polymerization of octafluorocyclobutane was carried out under different conditions by varyingdischarge power, pressure, plasma gas and plasma-gas/monomer ratio. Structure of polymerizedproducts was characterized by IR spectroscopy and ESCA measurement. It was found that therewere six elements in the products, i.e. C, F, Si, O, N and H. The probably existed groups in poly-mers wer investigated. By analyzing the resolved peaks of C_(1S) region in ESCA spectra, effect of thereaction conditions on degree of branching of the polymerized products and the relationship of thepolymer structure wth the mechanism of the competitive ablation and polymerization process werestudied. In addition, polymer deposition process occurring in glow discharge was discussed.     

Anode Magnetron Enhanced DC Glow Discharge Processes for Plasma Surface Cleaning and Polymerization

The objective of this study was to examine some fundamental factors involved in the design and construction of the anode magnetron dc glow discharge processes as well as its performance in plasma cleaning and polymerization. Those advantages of anode magnetron include the capability of the magnetron to operate at low pressure, as well as decreasing the thickness of cathode dark space, i.e., the negative glow which contains a higher concentration of ions and active species was more closely to the cathode surface, which makes the plasma surface cleaning and polymerization an effective and uniform processes. The deposition rate at a given discharge power is increased by the presence of anode magnetrons, and is also much higher relative to rf and af. The refractive index of dc plasma film at a given polymer thickness (such as TMS, 70 nm, RI: 2.4) is higher than rf, af, and cascade arc plasma (RI: 1.6–1.7).     

苯硫酚等离子体聚会及其结构与性能

应用外部电容耦合式等离子体聚合装置．研究了苯硫酚等离子体聚合规律，找到了最佳聚合条件，通过热失重、红外光谱、X－射线衍射、电子衍射、GC－MS和接触角测定等研究了聚合物结构与性能。电导率测定表明等离子体聚苯硫酚具有半导体性质。