低温等离子体处理尼龙66表面形态结构的研究

本文应用扫描电镜和广角Ｘ－ｒａｙ衍射仪研究了等离子体处理尼龙６６表面形成结构的变化。结果表明，随处理功率增大和时间增长，该蚀由非晶区向晶区发展。结晶度随之增大到最高值，然后下降。不同气体对尼龙６６表面刻蚀作用：Ｏ２＞Ａｉｒ＞Ｎ２．     

低温等离子体对聚偏氟乙烯表面处理的研究

本文通过ESR、电镜、接触角测定及交联和剪切强度测定等手段研究了在不同等离子体条件下,聚偏氟乙烯(PVF)表面在处理前后的变化。结果表明处理后PVF的粘接性能明显有所改善,剪切强度较未处理时提高两倍左右。     

低温等离子体对AN-MA共聚物膜的表面改性

采用低温等离子体技术对丙烯腈－马来酸酐共聚物膜进行表面改性,运用ＦＴＩＲ－ＡＴＲ技术定性分析了处理后共聚物膜表面发生的化学变化,探讨了等离子体处理条件对共聚物膜的水 量及肌酐和尿素去除率的影响。结果表明,选择合适的等离子体处理条件,可获得水通量小而对肌酐尿素去除率较高的丙烯腈－马来酸酐共聚物膜。     

等离子体处理改性玻璃纤维表面

本文研究了等离子体处理玻璃纤维表面的作用效果,分析了等离子体处理玻璃纤维表面所起的物理化学变化,探讨了玻璃纤维作为复合材料的增强材料在等离子体处理后,其润湿性提高的原因.     

气相含氟单体乳液共聚反应竞聚率的测定

用Ｈｅｎｒｙ定律关系气相单体分压与液相浓度间的关系,代放Ｍａｙｏ－Ｌｅｗｉｓ共聚物组成方程后测定了四的氟乙烯与偏乙烯在乳液聚合时的表观竞聚则得竞聚率有较好的置信区间,计算共聚物组成与ＮＭＲ测试结果相一致。     

低温等离子体技术处理聚苯乙烯微粒子的研究

介绍了辉光放电的低温等离子技术，对聚苯乙烯微粒颗粒表面进行处理，研究结果表明：聚苯乙烯微粒子表面的带电性能和吸附性能大为提高。     

氧等离子体对聚丙烯粉体的表面处理研究

用氧等离子体对聚丙烯（PP）粉体进行表面处理,采用水接触角（WCA）、红外光谱（IR）对处理前后PP粉体的水接触角、表面组分的变化进行了分析。实验结果表明,随着等离子体处理时间延长,水接触角减小。IR分析表明,在氧等离子体处理中,PP粉体表面有含氧极性官能团生成,导致粉体表面水接触角减小。     

低温等离子体处理对高强聚乙烯纤维表面影响的研究

采用空气低温等离子体处理高强聚乙烯纤维,测试处理前后纤维表面摩擦系数的变化,并采用电子扫描显微镜（SEM）和原子力显微镜（AFM）对纤维表面形貌进行观察分析。结果发现,空气低温等离子体处理的刻蚀作用会在纤维表面形成致密的＂小坑群＂,使得纤维表面产生剥落、联结,造成纤维表面的粗糙程度有所增加,其处理后的纤维表面静、动摩擦系数有所提高。     

聚偏二氟乙烯的低温等离子体氯化工艺研究

在低温等离子体气固流化床中对聚偏二氟乙烯进行流态化氯化制备氯化聚偏二氟乙烯,同时向反应器中引入低温液氯带走反应热,并控制不同的反应时间以获得不同氯含量的氯化聚偏二氟乙烯产品.试验表明:在输入电压1000V、体系压力常压、Cl2流量3 L/min的工艺条件下,可制得氯质量分数在5％～30％的氯化聚偏二氟乙烯产品.     

Surface properties of polymers treated with tetrafluoromethane plasma

Polymer films of poly(ethylene terephthalate), polypropylene, and cellophane were surface treated with tetrafluoromethane plasma under different time, power, and pressure conditions. Contact angles for water and methylene iodide and surface energy were analyzed with a dynamic contact angle analyzer. The stability of the treated surfaces was investigated by washing them with water or acetone, followed by contact angle measurements. The plasma treatments decreased the surface energies to 2–20 mJ/m² and consequently enhanced the hydrophobicity and oleophobicity of the materials. The treated surfaces were only moderately affected after washing with water and acetone, indicating stable surface treatments. The chemical composition of the material surfaces was analyzed with X-ray photoelectron spectroscopy (XPS) and revealed the incorporation of about 35–60 atomic % fluorine atoms in the surfaces after the treatments. The relative chemical composition of the C ls spectra's showed the incorporation of —CHF— groups and highly nonpolar —CF₂— and —CF₃ groups in the surfaces and also —CH₂—CF₂— groups in the surface of polypropylene. The hydrophobicity and oleophobicity improved with increased content of nonpolar —CF₂—, —CF₃, and —CH₂—CF₂— groups in the surfaces. For polyester and polypropylene, all major changes in chemical composition, advancing contact angle, and surface energy are attained after plasma treatment for one minute, while longer treatment time is required for cellophane. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 1591–1601, 1997     

Surface biomedical effects of plasma on polyetherurethane

Surface biomedical effects of plasma treatment and plasma polymerization on medical-grade polyetherurethane were studied. N₂ and Ar plasma treatments and hexamethyldisiloxane (HMDS) plasma polymerization were performed at a power of 100 W with exposure times ranging from 1 to 15 min. The results showed that the contact angle of water was decreased from 79° to 62° by N₂ and Ar plasma treatments, and N₂ plasma treatment caused a slight enhancement in anti-coagulability and anti-calcific behavior. HMDS polymerization resulted in a decrease from 79° to 43° in the contact angle and an increase from 30.5 to 37.4 s in the recalcification time. At the same time, the anti-coagulability of polymerized samples for the exposure time of 2-5 min was 2.5 times that of the untreated sample. Results of XPS and ESR analyses showed that HMDS deposited onto the polyetherurethane surface and formed new Si-N bonds, and increased the number of radicals in the sample. XPS analysis also showed that N₂ and Ar plasma treatments broke some of the C-O and C=O bonds at the surface and resulted in oxidation of the surface.     

Surface modification of polytetrafluoroethylene with tetraethoxysilane by using remote argon/dinitrogen oxide microwave plasma

The use of remote microwave plasma for the polymerization and deposition of tetraethoxysilane on the surface of polytetrafluoroethylene was investigated using a mixture of Argon and dinitrogen oxide as carrier gas. Layers with thicknesses of 0.5–3 μm were obtained, differing in chemical composition, surface energy, and flexibility/brittleness, depending on the plasma power and both the treatment and aging times. In general, milder treatments and shorter aging times resulted in higher contents of organic structural elements in the layers and greater flexibility and surface energy. Anchoring between the layers and the bulk polytetrafluoroethylene was at least partially caused by fibrils interconnecting the two components. These results were obtained by X‐ray photoelectron spectroscopy, Fourier transform infrared spectroscopy in the attenuated total reflection mode, contact angle measurements, and scanning electron microscopy combined with energy dispersive X‐ray analysis. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 1207–1216, 2000     

Surface Dynamics vs. Adhesion in Oxygen Plasma Treated Polyolefins

Polyethylene (PE) and polypropylene (PP) were oxygen plasma treated and aged in carefully reproducible conditions. The effect of aging on the surface chemistry, wettability and adhesion were studied using a combination of techniques: contact angle measurements, XPS, SSIMS, adhesion tests (shear and pull).

PE was found to be relatively insensitive to aging both in terms of wettability and adhesion, due to crosslinking during plasma treatment, which is likely to reduce macromolecular mobility within the surface layer.

In the case of PP, dramatic decreases of wettability occur with time, due to macromolecular motions leading to minimization of oxygen-containing functions at the surface. This behavior was shown to affect the adhesion performance of treated PP.     

Polysiloxane Softener Coatings on Plasma‐Treated Wool: Study of the Surface Interactions

Low temperature plasma (LTP) improves the shrink‐resistance of wool fabrics but impairs their softness, so different polysiloxane coatings were applied. Modifications in surface hydrophilicity and topography of fabrics and fibres have been recorded through drop test, contact angle and SEM, respectively. LTP improves the deposition of the polysiloxanes which, depending on their functionalities alter the original hydrophilicity of the wool surface. Softness and shrink‐resist results of the fabrics point out to a possible relationship between hydrophilicity of the wool fibre surface and the shrinkage behaviour of the fabrics. A possible mechanism of interaction between the different polysiloxane groups and the surface of untreated (UT) and LTP‐treated wool is proposed.

     

Surface Dynamics vs. Adhesion in Oxygen Plasma Treated Polyolefins

Polyethylene (PE) and polypropylene (PP) were oxygen plasma treated and aged in carefully reproducible conditions. The effect of aging on the surface chemistry, wettability and adhesion were studied using a combination of techniques: contact angle measurements, XPS, SSIMS, adhesion tests (shear and pull).

PE was found to be relatively insensitive to aging both in terms of wettability and adhesion, due to crosslinking during plasma treatment, which is likely to reduce macromolecular mobility within the surface layer.

In the case of PP, dramatic decreases of wettability occur with time, due to macromolecular motions leading to minimization of oxygen-containing functions at the surface. This behavior was shown to affect the adhesion performance of treated PP.     

Surface modification of polypropylene membrane by low‐temperature plasma treatment

Microporous polypropylene membranes were low temperature plasma treated with acrylic acid and allylamine. Parameters of plasma treatment were examined and optimized for the enhancement of membrane performance properties. Excess power damaged the membrane surface and excess monomer flow rate increased the reactor pressure to interfere with the glow discharge. Longer plasma treatment time resulted in even more plasma coating and micropore blocking. The contact angle with water decreased and wettabilities increased with the increase of plasma treatment time. Deposition of the plasma polymer on the membrane surface was confirmed by FTIR/ATR spectra of the treated surface. In determining the flux, the hydrophilicity of the surface played a role as important as that of the micropore size. Adequate plasma treatment could enhance both water flux and solute removal efficiency. Results from the BSA (bovine serum albumin) solution test confirmed that fouling was greatly reduced after the plasma treatment. The BSA solution flux through the plasma‐treated membranes depended on pH, whereas pH variation had no serious effects on the untreated membrane. Modification of the surface charge by the plasma treatment should exert a substantial influence on the adsorption and removal of BSA. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1555–1566, 2001     

低温等离子体处理UHMWPE纤维表面性能的多指标优化

利用正交表安排试验,对超高相对分子质量聚乙烯(UHMWPE)纤维进行空气低温等离子体处理,测试各处理条件下UHMWPE纤维的力学和表面摩擦性能;采用矩阵分析法对多指标正交试验结果进行优化分析,找出最优方案并进行黏着性试验验证。结果表明:经空气低温等离子体处理后,UHMWPE纤维的断裂强度有所减小,表面静、动摩擦因数有较大幅度的提高;处理纤维的最优方案为功率50 W、压强15 Pa、时间150 s,此时纤维的断裂强度损失率仅为2.53%,剥离功为未处理时的4.25倍,说明由矩阵分析法得出的最优方案在保证纤维断裂强度损失很小的情况下,黏着性得到了很大程度的改善。     

受冻融混凝土表面处理后水分侵入机理研究

采用硅烷凝胶对冻融损伤混凝土进行表面处理,通过毛细吸水和压汞试验技术研究表面处理前后的受冻融混凝土吸水性能和微观孔结构,并对水分侵入机理进行分析.结果表明:随着冻融循环次数的增加,混凝土毛细吸收系数和孔隙率成倍数提高.在吸水初期36 h,硅烷凝胶用量和冻融损伤度对毛细吸水影响不明显,后期差异越来越大.受冻融混凝土表层孔结构劣化导致的憎水层致密性差,使得外部液态水从“水汽传输”逐步过渡到与内部非憎水区的凝结水形成“水路传输”,是冻融损伤混凝土表面防水过早失效的根本原因.