NH3 Plasma Treatments of PET for Enhancing Aluminum Adhesion

A NH₃ plasma process has been studied for enhancing the adhesion of aluminum coatings on polyethyleneterephtalate (PET) films. According to our peel strength results, NH₃ plasmas increase markedly the adhesion of aluminum on PET compared to O₂ discharges, with a much shorter treatment time. A tentative model of nonhindered growth of Al-coating based on the Lewis basic character of the functionalities grafted by NH₃ plasma is proposed for Al-polymer interactions, and for explaining the various steps in the process. The effects of power input and treatment time on the polymer surface chemistry and on the metal-polymer peel strength have been evaluated. Treatment times as short as 0.1 s at 100 W proved to be the best conditions in NH₃ plasmas, for a significant increase in Al/PET adhesion, while longer treatments have a detrimental effect. This may explain why most authors have not discovered the benefits of NH₃ plasmas for improving the adhesion of metals on PET, and have preferred O₂ or air treatments. The relative basicity of PET grafted with N-containing functionalities has been measured by means of X-ray Photoelectron Spectroscopy (XPS) analysis of samples exposed to vapors of trichloromethane, a Lewis acid molecular probe. The Al/PET adhesion was evaluated by means of a 180° Peel Test.     

Cell Adhesion Micropatterning by Plasma Treatment of Alginate Coated Surfaces

Air plasma treatment, coupled to a masking technique, was used to promote micropatterned cell adhesion onto a cell-adhesion-resistant alginate coated surface. L-929 mouse fibroblasts were successfully confined into 50 m diameter cell-adhesive areas patterned inside a cell-resistant layer. The plasma treatment performed, albeit very mild, destroys the molecular architecture of the hydrophilic polysaccharide coating, leading to an enhancement of protein adsorption and hence of cell-adhesion. Both the cell-adhesion-resistant and the cell-adhesive regions are hydrophilic, yet they show a completely different behavior towards cells. Thus, they are a very interesting subject in the study of interfacial interactions in aqueous media, and, in particular, on the mechanisms of bio-adhesion at hydrophilic surfaces.     

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。     

Atmospheric Pressure Plasma Surface Treatment of Polymers and Influence on Cell Cultivation

Atmospheric plasma treatment is an effective and economical surface treatment technique. The main advantage of this technique is that the bulk properties of the material remain unchanged while the surface properties and biocompatibility are enhanced. Polymers are used in many biomedical applications; such as implants, because of their variable bulk properties. On the other hand, their surface properties are inadequate which demands certain surface treatments including atmospheric pressure plasma treatment. In biomedical applications, surface treatment is important to promote good cell adhesion, proliferation, and growth. This article aim is to give an overview of different atmospheric pressure plasma treatments of polymer surface, and their influence on cell-material interaction with different cell lines.     

Atmospheric Plasma Sterilization and Deodorization of Dielectric Surfaces

A method is presented for rapid and uniform sterilization and deodorization of dielectric surfaces. The technology is applicable to the inside surface of PET or glass bottles, polymer caps, plastic tubes, etc. The treatment is based on a pulsed RF discharge in air at atmospheric pressure (eventually with addition of argon) creating a nonequilibrium plasma on the treated surface. The plasma effectively destroys microorganisms in vegetative or sporulent form. It also slightly etches the polymeric material, removing some atomic layers and, thereby, cleaning it from aromatic organic components (deodorization). The process is short: PET bottles 1.5 L, in particular, can be treated in about 20 msec. The results of surface analysis and microbiological, chromatography, and spectroscopy tests are discussed. A device has been developed and integrated into an industrial-filling machine for online sterilization and deodorization of the inside surface of PET bottles before filling, and for sterilization of caps and bottle necks before seaming. It allows cold asceptic filling at a rate of 36,000 bottles per hour.     

PET表面锐钛矿-板钛矿相TiO2薄膜的制备及表征

利用改进的溶胶-凝胶法在经表面改性的PET(聚对苯二甲酸乙二醇酯)表面制备得到TiO2薄膜. 利用X射线衍射(XRD)、原子力显微镜(AFM)、UV-Vis 透光率曲线、接触角测试仪等测试手段对TiO2样品的性能进行表征.结果表明, PET表面过渡层的引入有效地改善了有机基底与无机薄膜之间的界面相容性, 在其表面形成透明、均一、附着力良好且具有光催化活性的TiO2薄膜.通过控制实验过程, 在低温下成功制备了不同锐钛矿/板钛矿比的TiO2薄膜,同时发现适量板钛矿相的存在能有效提高薄膜的光致亲水性.     

Molecular Engineering of Surfaces by Plasma Copolymerization and Enhanced Cell Attachment and Spreading

The plasma copolymerization of acrylic acid and methyl vinyl ketone with 1,7-octadiene is reported. A range of surfaces including hydrocarbon plasma polymer, carbonyl-containing plasma copolymer and carboxyl-containing plasma copolymers have been prepared and characterized by means of X-ray photoelectron spectroscopy. The stability of these surfaces in water has been assessed at 37°C. The influence of their functional group chemistries on the attachment and spreading of osteoblast-like (ROS 17/2.8) and bone marrow stromal cells (BMSC) has been explored. The data reported show a strong correlation between the carboxyl group and the attachment and spreading of both ROS cells and BMSC. This relationship has been explored in some detail with the ROS cells. Actin-staining by direct immunofluorescence was used to visualize changes in cytoskeleton of ROS cells with substratum chemistry. As the concentration of the carboxyl groups increased cell number and cell spreading were notably enhanced. As few as 5 carboxyls per 100 carbons were sufficient to support good attachment and with cells showing well-defined polygonal cell morphology. Although cells attached to a hydrocarbon plasma polymer surface these cells had failed to spread. The attachment and spreading of BMSC were compared on a carboxyl-containing surface and on a hydrocarbon surface. There was a more marked difference in the number of cells that had attached to these two surfaces (cf. ROS cells). The spreading on the carboxyl surface was much more typical of BMSC. Results from an extended culture using primary cultures of bone marrow cells (BMC) are reported. These cells were not trypsinized and appear to be less sensitive to differences in surface chemistry (cf. BMSC). Even so, the results at 10 days indicate much greater biosynthetic activity on the carboxyl-containing surface.     

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%.     

Surface Initiated Polymerization on Pulsed Plasma Deposited Polyallylamine: A Polymer Substrate‐Independent Strategy to Soft Surfaces with Polymer Brushes

The deposition of polyallylamine (PAA) adlayers by pulsed plasma polymerization on various types of polymeric substrates has been explored as a general route to amino functionalized polymeric surfaces. These amino groups are highly suitable for anchoring an atom transfer radical polymerization (ATRP) initiator via a robust amide linkage. Subsequent surface initiated ATRP (SI‐ATRP) of monomethoxy oligo(ethylene glycol) methacrylate (MeOEGMA) resulted in polyMeOEGMA brush grafted polymer surfaces. This combined strategy of pulsed plasma polymerization with SI‐ATRP was demonstrated for five different polymeric substrates namely polyether ether ketone (PEEK), polyethylene terephthalate (PET), polyimide (PI), polypropylene (PP), and polytetrafluoroethylene (PTFE). Analysis of brush layers by attenuated total reflection infrared (ATR‐IR) spectroscopy as well as X‐ray photoelectron spectroscopy (XPS) fully corroborated the success of the proposed strategy for all substrate types.

     

Surface Behavior of Polyamide 6 Modified by Barrier Plasma in Oxygen and Nitrogen

Polyamide (PA) 6 was modified by diffuse coplanar surface barrier discharge (DCSBD) plasma in an atmosphere of nitrogen and oxygen. The surface roughness decrease of PA 6 was detected by AFM and nano-indentation after modification in DCSBD plasma. A significant increase in O/C and N/C ratios of plasma-modified PA 6 using XPS analysis was found. The results show the importance of introducing oxygenic polar functional groups on the polymeric surface in order to increase its surface energy during a short time of plasma activation. The modification of PA 6 by DCSBD oxygen plasma was more efficient than by nitrogen plasma.     

Surface Modifications Produced by N2 and O2 RF Plasma Treatment on a Synthetic Vulcanized Styrene-Butadiene Rubber

A low-pressure gas RF plasma-treatment has been used to improve the adhesion of a synthetic vulcanized rubber to polyurethane adhesive as an environmentally friendly alternative surface treatment to the conventional chemical treatments. A sulfur vulcanized styrene-butadiene rubber (R2) containing a noticeable amount of zinc stearate and paraffin wax (both providing a lack of adhesion) in its formulation was used. Two different gases (oxygen and nitrogen) were used to generate the RF plasma, which was performed at 50 Watt for 1–15 min. The modifications produced on the R2 rubber surface by the RF plasma treatments were assessed by using advancing and receding contact angle measurements, ATR-IR spectroscopy, X-ray Photoelectron Spectroscopy (XPS), Scanning Force Microscopy (SFM), and Scanning Electron Microscopy (SEM). Adhesion evaluation was obtained from T-peel tests of joints produced between plasma treated R2 rubber and a polyurethane adhesive. The plasma treatment produced a decrease in advancing and receding contact angle values on R2 rubber, irrespective to the gas used to generate the RF plasma. The treatment with RF plasma produced the partial removal of hydrocarbon moieties from the rubber surface and the generation of oxygen moieties. An increase in surface roughness was also produced. The degree of oxidation and the amount of hydrocarbon-rich layer removed from the R2 rubber surface was more important by treating with oxygen plasma. The treatment of rubber in oxygen plasma for 1 minute was enough to noticeably increase adhesion of R2 rubber to polyurethane adhesive. However, an extended treatment (15 min.) was needed when nitrogen plasma was applied to R2 rubber. The loci of failure in the joints produced between the plasma treated R2 rubber and the polyurethane adhesive was assessed by using ATR-IR spectroscopy. A mixed failure (partially adhesional and partially cohesive failure in the rubber) in the joints produced with plasma treated R2 rubber joints was always obtained.     

骨髓基质干细胞在等离子体处理PEGDA基凝胶表面的黏附和增殖

通过低温等离子体技术对聚乙二醇双丙烯酸酯(PEGDA)/甲基丙烯酸β-羟乙酯(HEMA)共聚物水凝胶生物材料进行表面改性,以骨髓基质干细胞(BMSc)为细胞模型,考察了细胞在等离子体表面改性前后的水凝胶材料的黏附和增值行为,材料的表面性能通过 X 射线光电子能谱、接触角和扫描电镜进行表征.研究结果表明,材料表面经氩等离...     

Surface modifications of PET in argon atmospheric pressure plasma: Gas flow rate effect

The correlation between plasma optical properties and the treated polyethylene terephthalate (PET) surface characteristics have been studied at various Ar flow rate. The rotational T_rot and vibrational T_vib temperatures of APPJ were determined from SPS emission band. The pristine and plasma-treated PET surfaces were characterized by several techniques including X-ray photoelectrons spectroscopy (XPS), Raman spectroscopy, contact angle (CA), and atomic force microscope (AFM). The CA decreased rapidly in the flow rate range 1–3 L/min and weakly dependent as flow rate > 3 L/min. XPS results showed that C 1s % of plasma-treated PET surfaces decreases and has a minimum for samples treated at 3–4 L/min, while O 1s has a maximum at the same flow rate range. The carbon C 1s peak of pristine and plasma treated PET samples resolved into five subcomponents: C–C, C–O, C=O, O–C=O, and π–π bonds with variable percentage ratio accordance to the plasma gas flow rate. Raman data revealed a partial loss in the crystallinity of the treated PET samples and also confirm the incremental of C–O band at Ar flow rate of 3 L/min. AFM images showed that the surface roughness of treated PET films increases as Ar flow rate increases.     

Development of Atmospheric Pressure Low Temperature Surface Discharge Plasma Torch and Application to Polypropylene Surface Treatment

We have finally succeeded in producing the plasma jet by use of the surface discharge plasma torch that can be expected to make larger the diameter of torch in the comparatively easy way. It can be checked that the active species in the jet obtained are different depending on the direction of connection, and also it was clearly found that much O and N₂ is included in them. Consequently, etching was confirmed at the position of 10 mm from the torch end in the surface treatment of polypropylene film, but etching was not confirmed at the position of 20 mm.     

热致液晶（LC70）／PET共混物的结构与性能

采用ＷＡＸＤ、ＤＳＣ、ＰＯＭ、ＳＥＭ和力学测试方法研究了ＬＣ７０／ＰＥＴ原位复合材料的结构与性能。结果表明,当ＬＣ７０／ＰＥＴ＜２０％时,ＬＣ７０对ＰＥＴ的结晶生长具有一定促进作用;当ＬＣ７０／ＰＥＴ＞３０％时,共混物结晶能力迅速下降,结晶放热和熔融焓明显降低。     

Surface Energy and Adhesive Properties of Polyamide 12 Modified by Barrier and Radio-Frequency Discharge Plasma

Summary. The polyamide 12 foil with sufficient surface and adhesive properties to other substrates can be prepared by discharge plasma modification. For improvement of bonding and printing of polymer a surface barrier discharge plasma in N₂ and O₂ as well as a radio-frequency discharge plasma in air has been studied. A significant increase in surface energy of the polymer as well as in strength of adhesive joint to more polar polymer was found. The chemical changes of PA 12 modified by plasma were analyzed using fourier transform infra red – attenuated total reflection (FTIR–ATR) spectroscopy, and X-ray photoelectron spectroscopy (XPS) measurements. The observed changes of surface properties of the polymer due to aging were not important.     

PET导电纤维的制取及研究

以过氧化二苯甲酰为引发剂,使丙烯睛在涤沦(PET)纤维上接枝共聚。接枝纤维在含铜化合物,含硫还原剂溶液中反应,制备PET导电纤维。讨论了影响接枝共聚的各种因素,选择出最佳聚合条件。对该纤维的导电成份和结构以及性能进行了研究。     

RF Plasma Deposition of PEO-Like Films: Diagnostics and Process Control

Organic thin films deposited by means of radio-frequency glow discharges fed with Triglyme vapors have been investigated to explore the feasibility for deposition of organic thin films with polyethylene oxide-like features. The film chemical composition has been analyzed by means of X-ray Photoelectron Spectroscopy and FT Infrared Absorption Spectroscopy. Plasma phase diagnostics has been accomplished by means of Optical Emission Spectroscopy. It is shown that the surface density of ether carbon, which is considered the marker of the content of ethylene oxide units in the coating, decreases as the power input is increased. It is also shown that the retention of monomer structure in the film can be easily controlled in situ by actinometric optical emission spectroscopy.     

超临界二氧化碳处理对聚酯纤维结构及其性能的影响

用DSC、扫描电镜、X射线衍射、萨那蒙法对超临界二氧化碳处理聚酯纤维的熔点、表面形态结构、聚集态结构进行测定,并对处理后织物的收缩性能进行了分析探讨。实验结果表明：随着超临界二氧化碳处理温度、压力的提高,聚酯纤维的熔点、熔融热略有增加,纤维表面的低聚物增多,纤维的结晶度增加,取向度略有下降,同时聚酯织物的收缩率增加。预定型处理有助于提高聚酯纤维的热稳定性,降低二氧化碳处理对聚酯织物收缩率的影响。