Film morphology, orientation and performance of dodecyl/carboxyl functional polysiloxane on cotton substrates

A novel polysiloxane (RCAS) bearing dodecyl and carboxyl side groups was synthesized by reaction of a dodecyl/amino functionalized polysiloxane with maleic anhydride. Film morphology, molecular orientation and performance of the synthesized polysiloxane on cotton substrates were investigated by field emission scanning electron microscope (FESEM), atomic force microscope (AFM), X-ray photoelectron microscope (XPS) and so on. Affected by the dodecyl and polar carboxyl side groups, RCAS formed a semi hydrophilic, macroscopic smooth but actually uneven siloxane film with many pillar-likes or small humps on the treated substrate surfaces. On the natural cotton surface, RCAS may take such an orientation to form its film that the Si-CH₃, Si-C₁₂H₂₅ groups projected outward into air, while the carboxyl groups pointed inward to the substrate, interacting with the hydroxyls of the cotton substrates in ester and hydrogen bonds or twisted away from the negatively charged cotton fiber surface. As a result of such a film-formation, RCAS provided the treated fabric with not only a good wettability of about 22.96 s and a whiteness of 88.44°, but also an improved softness as well as thickening handle.     

Surface morphology of cellulose films prepared by spin coating on silicon oxide substrates pretreated with cationic polyelectrolyte

Flat cellulose films were prepared and morphologically modified by spin coating a cellulose/N-methylmorpholine-N-oxide/H₂O solution onto silicon oxide substrates pre-coated with a cationic polyelectrolyte. Spin-coated cellulose films were allowed to stably form on the silicon oxide substrates by pretreatment with either polydiallyldimethylammonium chloride (PDADMAC) or polyvinylamine (PVAm). The film surfaces obtained were analyzed by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). AFM topographical images of the cellulose film surfaces showed a different morphology depending on the underlying polymer, where PVAm pretreatment brought about an anisotropic surface topology. These results suggest that the specific attraction acting at the cellulose/polymer interface influences both the film formation and surface morphology of the cellulose layer. Differences in the solvent used to precipitate cellulose caused variations in the surface roughness by affecting the cellulose separation behavior. The morphological features of spin-coated cellulose film surfaces could be altered to some extent by these film preparation techniques.     

Superhydrophobic surfaces prepared from water glass and non-fluorinated alkylsilane on cotton substrates

Superhydrophobic surfaces have been successfully prepared by sol-gel method using water glass as starting material. Such surfaces were obtained first by dip-coating the silica hydrosols prepared via hydrolysis and condensation of water glass onto cotton substrates, then the surface of the silica coating was modified with a non-fluoro compound, hexadecyltrimethoxysilane (HDTMS), to gain a thin film through self-assembly, superhydrophobicity with a water contact angle higher than 151° can be achieved. The morphology and surface roughness were characterized by SEM and AFM.     

Combined XPS and SIMS study of amino acid overlayers

Factors influencing the SIMS fragmentation patterns are studied for three simple amino acids-glycine, α-alanine, and serine-deposited onto Ag substrates from aqueous solution. Secondary ion emissions are measured for 1 keV Ar⁺ ions incident at 70° from sample normal as a function of substrate preparation and solution concentration. Studies by XPS and X-ray induced AES prior to SIMS analysis show that the amino acids adsorb in a film on the Ag surface and that the film thickness increases with solution concentration. In addition, considerable amounts of amino acid can be deposited on the surface from a water film retained during extraction from a concentrated solution. On acid etched samples, positive ion fragments of mass AgM, Ag(M ? 45), Ag, M + 1, and M ? 45 are observed, where M is the molecular, weight of the parent amino acid. With the exception of the (M + 1)⁺ fragment, these peak intensities behaved similarly for the different surface concentrations. When the adsorbed film grows too thick, the positive molecular ion emissions drop considerably; this substantiates the need for proximity between the Ag substrate and the amino acid molecule.     

铜薄膜等离子改性及表面增强拉曼光谱的研究

表面增强拉曼光谱(surface-enhanced Raman spectroscopy, SERS)技术是一种基于探测吸附于金属基底表面分子振动光谱的快速无损检测方法,目前广泛应用于表面吸附、电化学催化、传感器、生物医学检测和痕量的检测与分析等领域。本实验采用直流磁控溅射技术在BK7玻璃基底上沉积一层厚度为50 nm的金属铜薄膜,在Ar离子轰击作用下获得不同表面粗糙度的金属铜薄膜样品,从而制备具有不同表面增强拉曼光谱活性的金属基底。实验样品分别通过X射线衍射仪（XRD）、原子力显微镜（AFM）、分光光度计、拉曼光谱仪表征其结构、表面形貌及光学性质。测试结果表明铜膜在Ar离子束轰击前后,样品X射线衍射谱的峰值强度没有发生变化,说明其晶相结构未发生改变;随着离子束能量的增加,薄膜表面粗糙度改变,光学散射强度随着表面粗糙度的增加而增强;离子束薄膜表面改性后,以罗丹明B(Rh B)为探针分子,表征薄膜样品表面增强拉曼的活性,通过对比不同样品表面Rh B的拉曼光谱,发现其光谱强度随金属铜薄膜样品表面粗糙度的增加而增强。     

Electroless plating of copper on surface-modified glass substrate

This work focuses on developing a novel convenient method for electroless copper deposition on glass material. This method is relied on the formation of amino (NH₂)-terminated film on the surface of glass substrate, by coating polyethylenimine (PEI) on glass matrix and using epichlorohydrin (ECH) as cross-linking agent. The introduced amino groups can effectively adsorb the palladium, the catalysts which could initiate the subsequent Cu electroless plating, onto the glass substrate surface. Finally, a copper film is formed on the palladium-activated glass substrate through copper electroless plating and the surface-coppered glass material is therefore acquired. X-ray diffraction (XRD), atomic force microscope (AFM), scanning electron microscopy (SEM) images combined with energy diffraction X-ray (EDX) analysis demonstrate the successful copper deposition on the surface of glass substrate.     

The Uniform Si-O Coating on Cotton Fibers by an Atmospheric Pressure Plasma Treatment

A uniform Si-O coating on cotton fabric was produced at atmospheric pressure by a plasma treatment. Before the plasma discharge, a pretreatment with hexamethyldisiloxane (HMDSO)-ethanol mixture solvents on the fabric was employed. The surface morphology and chemical structure of the plasma-treated fibers were analyzed by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray diffraction (XRD) analyses. The SEM results showed that a uniform, continuous film was formed on the cotton fiber surface. It was much rougher than the uncoated fiber. The FTIR results showed that the coatings contained most of the Si-O functional groups. These Si-O bonds, broken from the Si-O-Si functional groups by the plasma electron impact, had connected with the cellulose by chemical bonds of Si-O-Cellulose. XRD patterns revealed the existence of a crystalline structure within the thin coating film. The UV-vis transmission of the cotton textile was greatly reduced by such coatings.     

Amino functionalization of carbon nanotube surfaces with NH3 plasma treatment

NH₃ plasma treatment of carbon nanotube (CNT) surfaces was performed with the purpose of incorporating amino groups onto the surface. Amino groups incorporated onto the CNT surface were indentified and quantified using chemical derivatization with pentafluorobenzaldehyde and subsequent characterization with X-ray photoelectron spectroscopy (XPS). The amount of incorporated amino groups reached a maximum value with increasing plasma power. The incorporation of amino groups was seriously affected by the degradation of the CNT surface during the plasma treatment, which became very serious at high plasma power, as verified with optical emission spectroscopy (OES) and FT-IR analyses. The type of species present in the plasma discharge also seems to be important for amino group functionalization; partially decomposed ammonia species are considered to be more favorable than fully decomposed atomic species.     

Effect of substrate morphology on the roughness evolution of ultra thin DLC films

The effect of substrate roughness on growth of ultra thin diamond-like carbon (DLC) films has been studied. The ultra thin DLC films have been deposited on silicon substrates with initial surface roughness of 0.15, 0.46 and 1.08 nm using a filted cathodic vacuum arc (FCVA) system. The films were characterized by Raman spectroscope, transmission electron microscope (TEM) and atomic force microscopy (AFM) to investigate the evolution of the surface roughness as a function of the film thickness. The experimental results show that the evolution of the surface morphology in an atomic scale depends on the initial surface morphology of the silicon substrate. For smooth silicon substrate (initial surface roughness of 0.15 nm), the surface roughness decreased with DLC thickness. However, for silicon substrate with initial surface roughness of 0.46 and 1.08 nm, the film surface roughness decreased first and then increased to a maximum and subsequently decreased again. The preferred growth of the valley and the island growth of DLC were employed to interpret the influence of substrate morphology on the evolution of DLC film roughness.     

Studies on morphology and molecular arrangement of pentacene on different substrates

Pentacene (C₂₂H₁₄) thin films with different thicknesses were fabricated to study the dynamic growth process and morphology of pentacene on different substrates. A discontinuous monomolecular layer was observed when a pentacene thin film is about 0.5 nm thick on native oxide silicon wafer. The terraced islands and dendritic structure gradually formed with increasing pentacene thin film thickness. The height of each layer is about 1.4 nm which corresponds well with the length of the long axis of the pentacene molecule at 1.45 nm. Experimental results show that the pentacene molecule is perpendicular to the silicon wafer surface with a slight tilted angle. However, the pentacene molecular orientation on a polymer pre-covered indium tin oxide coated substrate could not give any indication on the scale of nanometers. The surface roughness of substrates strongly influences pentacene molecular diffusion and the morphology of pentacene thin films.     

Dissolution and Regeneration in Films of Natural Luffa in 1-butyl-3-methylimidazolium Chloride

Regenerated cellulose film was successfully prepared from natural luffa, a new cellulose raw material. A pretreatment of natural luffa was carried out by an alkali and hydrogen peroxide mixed solution. The dissolution process of the pretreated luffa in 1-butyl-3-methylimidazolium chloride ([BMIM]C1) was observed by polarized optical microscope. The structures and properties of the luffa films were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric (TGA), and porosity measurements. The results showed that the luffa fibers were transformed to fibrils after the pretreatment. [BMIM]Cl was a good non-derivatizing solvent for the luffa cellulose. The solution conditions were 80°C and 10 h for a 15% solution. After being regenerated, as films, from the luffa/[BMIM]Cl solution, the crystalline structure of the luffa film was transformed completely from cellulose I to cellulose II. The film showed the strong characteristic functional groups of cellulose in FTIR results. The surface of the film was smooth with a compact structure. The porosity of the film was 66.2% and the average pore size was 17.8 nm. It was thermally stabile up to 280°C.     

Surface roughness analysis and magnetic property studies of nickel thin films electrodeposited onto rotating disc electrodes

Ni films were electrodeposited onto polycrystalline gold substrates mounted on a rotating disc electrode. The effects of rotation speed, film thickness and current density on the kinetic roughening and magnetic properties of the films were investigated. The film surface roughness was imaged using an atomic force microscope (AFM). The results indicate that the film roughness increases as the film thickness or deposition current density increases. We found that the electrodeposited Ni films exhibit anomalous scaling since both local and large-scale roughnesses show a power-law dependence on the film thickness. The effect of electrode rotation speed on the film surface roughness was also investigated. Scanning electron microscopy studies (SEM) had a good agreement with the AFM results. The average crystalline size of the film surfaces is also calculated from X-ray line broadening using (220) peak and Debye–Scherrer formula. The obtained results agree with that of AFM and SEM. The Ni thin films which are grown at different deposition current densities and rotation speeds exhibit in-plane magnetization with coercivities less than 110 Oe.     

Fabrication of a superhydrophobic ZnO nanorod array film on cotton fabrics via a wet chemical route and hydrophobic modification

A superhydrophobic ZnO nanorod array film on cotton substrate was fabricated via a wet chemical route and subsequent modification with a layer of n-dodecyltrimethoxysilane (DTMS). The as-obtained cotton sample was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), scanning probe microscope (SPM) and X-ray photoelectron spectroscopy (XPS), respectively. The wettability of the cotton fabric sample was also studied by contact angle measurements. The modified cotton fabrics exhibited superhydrophobicity with a contact angle of 161° for 8 μL water droplet and a roll-off angle of 9° for 40 μL water droplet. It was shown that the proper surface roughness and the lower surface energy both played important roles in creating the superhydrophobic surface, in which the Cassie state dominated.     

Preparation of hydrophobic coating on glass surface by dielectric barrier discharge using a 16 kHz power supply

A 16 kHz power supply was used to investigate the preparation of hydrophobic film on glass surface by means of atmospheric pressure dielectric barrier discharge (DBD). Air nonthermal plasma was induced between the two parallel electrodes with a glass plate as dielectric barrier. The process for hydrophobic film includes two parts: one is plasma pretreatment to produce active layer on glass surface, another is to form hydrophobic film on glass surface by means of the interaction between air plasma and polydimethylsiloxane oil. The surface changes were observed using contact angle measurement and atomic force microscope. The results show DBD can increase surface roughness, and effectively improve glass surface activation and form a hydrophobic coating on glass surface, and it is possibility to prepare hydrophobic glass with middle frequency power supply.     

Crystallizaion and surface morphology of poly(vinylidene fluoride)/poly(methylmethacrylate) films by solution casting on different substrates

The dependence of surface structure of the poly(vinylidene fluoride) (PVDF)/poly(methylmethacrylate) (PMMA) films by solution casting on properties of seven substrates was investigated by wide angle X-ray diffraction (WAXD), Fourier transform infrared (FTIR), scanning electron microscope (SEM) and differential scanning calorimetry (DSC). It was revealed that the polyblend films obtained by casting onto each substrate contained exclusively β phase PVDF. Higher crystallinity of the film was obtained by casting onto ceramic, polytetrafluoroethylene (PTFE), copper (Cu), stainless steel and glass substrates than that by casting onto aluminium (Al) and polypropylene (PP) substrates, depending on the degree of close lattice matching. The surface crystalline structure of PVDF was strongly affected by the wettability of substrate. The largest size of PVDF spherulitic crystal structure with about 6 μm presented in the casting film grown at the air/solution interface on glass substrate, while the smallest spherulite size with about 3 μm was generated by casting onto PTFE, stainless steel and PP substrates. It implied that the higher surface tension the substrate had, the larger PVDF spherulite grew at the air/solution interface.     

Generation of a stable surface concentration of amino groups on silica coated onto titanium substrates by the plasma enhanced chemical vapour deposition method

This report describes the amino functionalisation of the surface of plasma enhanced chemically vapour deposited silica films (PECVD-SiO₂), which were coated onto titanium substrates. Amino groups were linked to PECVD-SiO₂ via 3-aminpropyl triethoxysilane (APTES). We showed that the APTES functionalised PECVD-SiO₂ surfaces contained a high packing density of amino groups (67-92 NH₂ groups per nm²), indicative of a multilayered and highly cross-linked APTES film. 65-66% of the original surface concentration of APTES was retained on the PECVD-SiO₂ surface after incubation under physiological conditions, indicating that APTES films are relatively stable on PECVD-SiO₂ in these environments. The stability of the amino groups obtained on PECVD-SiO₂ in this study is much higher compared to other hydroxyl-bearing materials, such as titanium. Therefore, PECVD-SiO₂ films may find use as functional biomaterial coatings and as intermediate adhesion layers in silanisation processes.     

不同射频输入功率下制备的氟化类金刚石碳膜疏水性研究

以高纯石墨作靶、氩气（Ar）和三氟甲烷（CHF₃）为源气体,用反应磁控溅射法在不同射频功率下制备了氟化类金刚石碳（F-DLC）膜,并对其疏水性进行研究.双蒸水液滴与膜表面接触角的测试结果表明,所制备薄膜表面的最大水接触角可达115°左右.通过原子力显微镜获得的薄膜表面AFM图谱、拉曼光谱以及傅里叶变换红外光谱探讨了影响薄膜的疏水性的因素.结果表明,薄膜的疏水性与薄膜的表面粗糙度和表面键结构直接相关,表面粗糙度越大,疏水性越好,但与薄膜中的F含量和sp³/sp²的比值并未呈单调增加或减小的对应关系.射频输入功率影响着薄膜的沉积速率,与薄膜表面粗糙度、薄膜中芳香环单核的比例以及薄膜表面的键结构（F的接入方式）直接相关. 关键词： 疏水性 反应磁控溅射 氟化类金刚石膜 射频功率     

Improvement of hydrophobic properties of silk and cotton by hexafluoropropene plasma treatment

Plasma surface-treatment of silk and cotton fabrics were carried out in a hexafluoropropene (C₃F₆) atmosphere under different experimental conditions. Analysis of the treated fibers by X-ray photoelectron spectroscopy (XPS) indicated about 50 at% fluorine atoms were incorporated in the surface structure of two fibers and confirmed the presence of -CF, -CF₂, -CF₃ groups on the surface. After water-washing and alcohol-extraction, though partial loss of fluorine from the surface has been observed, contact angle and wet-out time measurements on the fibers still show much improved hydrophobic properties. The other properties of the treated fabrics, such as water vapor permeability and tensile strength were also evaluated.     

Chemical bath deposition of hausmannite Mn3O4 thin films

A low-temperature chemical bath deposition (CBD) technique has been used for the preparation of Mn₃O₄ thin films onto glass substrates. The kinetic behavior and the formation mechanism of the solid thin films from the aqueous solution have been investigated. Structure (X-ray diffraction and Raman), morphological (atom force microscope), and optical (UV-vis-NIR) characterizations of the deposited films are presented. The results indicated that the deposited Mn₃O₄ thin films of smooth surface with nanosized grains were well crystalline and the optical bandgap of the film was estimated to be 2.54 eV.     

纳米ZnO的表面化学修饰及其分析表征

采用水溶性羟丙基甲基纤维素HPMC对无机纳米ZnO粒子进行物理吸附处理 ,获得了核为无机纳米ZnO ,外壳为水溶性高分子HPMC的粒子。然后在其上进行了甲基丙烯酸甲酯的接枝聚合。采用红外光谱、差热分析的方法对复合粒子进行了表征 ,并采用透射电镜观察了粒子的形貌。红外光谱表明在纳米ZnO的表面吸附了HPMC并接枝了PMMA ,差热分析表明HPMC ,HPMC g PMMA和ZnO/HPMC g PMMA的热稳定性逐渐提高 ,透射电镜观察表明 ,在纳米ZnO的表面粘附了一层聚合物 ,成功地实现了纳米粒子的表面修饰。