吸附剂预沉积超滤膜过滤腐殖酸影响研究

以自备羟基铁(FeO_xH_y)作为吸附剂,通过吸附剂预沉积超滤的方法,考察吸附磷酸盐前后对超滤膜过滤腐殖酸时的膜通量及膜出水水质的影响。实验结果表明:吸附剂预沉积超滤膜较膜滤,膜比通量升高,水质改善,且存在一个最佳吸附剂投加值0.45 g/L。吸附剂在吸附了一定量磷酸盐后,沉积层致密性变差、粗糙程度变大、膜比通量升高值少,膜出水水质也存在一定程度下降。     

聚电解质静电沉积改性制备高性能反渗透膜

利用次氯酸钠溶液对商品反渗透膜表面进行氯化处理,然后将聚阳离子电解质壳聚糖通过静电吸附作用沉积在RO膜的表面,系统地研究了氯化过程的pH、氯化时间、次氯酸钠浓度、壳聚糖浓度及其沉积时间对膜性能的影响,以制备出高通量、高截留率的RO膜。在压力1.55 MPa、原料液温度（298±1）K的条件下,测定RO膜处理2000 μg·g^-1氯化钠溶液的水通量和截留率。结果表明,当pH=9、氯化时间为30 min、次氯酸钠浓度为1000 mg·L^-1时,水通量较原膜提高了约19.89%,截留率略有提高;当壳聚糖浓度为0.1%（质量分数）、沉积时间为30 min时,改性膜的接触角降低到34.88°,亲水性提高,水通量较氯化后的RO膜几乎保持不变,为60.55 L·m^-2·h^-1,截留率达到了99.56%。经过氯化和沉积改性后的RO膜水通量和截留率均得到了提高。     

聚电解质静电沉积改性制备高性能反渗透膜

利用次氯酸钠溶液对商品反渗透膜表面进行氯化处理,然后将聚阳离子电解质壳聚糖通过静电吸附作用沉积在RO膜的表面,系统地研究了氯化过程的p H、氯化时间、次氯酸钠浓度、壳聚糖浓度及其沉积时间对膜性能的影响,以制备出高通量、高截留率的RO膜。在压力1.55 MPa、原料液温度(298±1)K的条件下,测定RO膜处理2000μg·g-1氯化钠溶液的水通量和截留率。结果表明,当p H=9、氯化时间为30 min、次氯酸钠浓度为1000mg·L-1时,水通量较原膜提高了约19.89%,截留率略有提高;当壳聚糖浓度为0.1%(质量分数)、沉积时间为30 min时,改性膜的接触角降低到34.88°,亲水性提高,水通量较氯化后的RO膜几乎保持不变,为60.55 L·m-2·h-1,截留率达到了99.56%。经过氯化和沉积改性后的RO膜水通量和截留率均得到了提高。     

气相沉积BN膜的性能及形成机制的研究

用射频等离子体辅助化学气相沉积技术制备了ＢＮ膜,对以Ａｒ＋１０％Ｈ２（体系分数）,Ｈ２和Ｎ２气为载气沉积的膜,进行了ＦＴＩＲ,ＴＥＭ,ＳＥＭ等分析,比较了不同载气下膜层的立方氮化硼含量,膜基结合力,膜层残余应力,硬度和耐磨性,对立方氮化硼的形成机制进行了探讨。     

电沉积巨磁电阻纳米材料的研究进展

对二维纳米巨磁电阻材料（包括纳米金属多层膜（人工超晶格）、不连续多层膜、自旋阀多层膜、纳米金属颗粒膜等）和一维纳米巨磁电阻材料——纳米金属多层线的电化学制备、性能进行了总结。介绍了巨磁电阻材料在制作超高灵敏度微型传感器、高密度读出磁头、磁随机存储器以及磁电子器件等方面的应用。指出了纳米巨磁电阻材料在制备及应用过程中存在的问题及其今后的发展方向。     

铝合金表面电解沉积稀土转化膜工艺研究

研究了一种通过电解沉积方法在防锈铝LF21表面上生成铈盐转化膜的工艺,应用正交实验研究了有关因素对成膜过程的影响并获得了最佳的技术参数用极化曲线、交流阻抗和中性盐雾试验等方法测试了该工艺形成膜层的耐蚀性能及其组成一结果表明：经过电解沉积稀土转化膜处理后,防锈铝的阳极腐蚀过程受到了阻滞,自然腐蚀电位负移;与经过化学转化膜处理后相比,其耐蚀性能有显著提高,可通过400h的中性盐雾实验,亲水性能亦有明显提高。     

液相沉积类金刚石膜的结构与性能研究

探讨了液相沉积法制备类金刚石的新工艺,并采用XPS,Raman光谱和SEM等对所得膜的结构进行表征,证实所得的是类金刚石膜。液相沉积得到的类金刚石膜与钛合金基材之间具有较强的结合强度,并具有较低的摩擦系数和一定的耐磨损能力。     

电沉积银纳米膜的光学性质研究

电沉积制备的银纳米膜的X 射线光电子能谱测试表明,纳米膜中的银显示出银元素的特征峰;采用四探针测试仪测量银纳米膜的电导率,发现银纳米膜的电导率比纯银要下降两个数量级;X射线衍射分析发现,银纳米膜的衍射峰相对于纯银发生了宽化,计算得出平均颗粒大小为50nm;紫外-可见分光光度计测量了纳米膜的吸光度,其吸收峰发生"蓝移";银纳米膜的熔点也会变低;用椭圆偏振仪测试不同波长下的复折射率和复介电常数及纳米膜的厚度;用Z 扫描装置测量出银纳米膜具有非线性折射性质,并计算了非线性折射系数n2达2 34×10-11esu。     

PVDF微滤膜表面改性与沉积Ag纳米颗粒研究

本文采用聚乙烯吡咯酮(PVP)和过硫酸铵(APS)对聚偏氟乙烯(PVDF)膜表面改性处理,并将纳米Ag颗粒负载在PVDF膜表面,制备了PVDF-PVP-Ag和PVDF-APS-Ag膜。结果表明PVP通过物理吸附在PVDF膜表面,使得膜的亲水性得到改善,沉积Ag纳米颗粒后膜的亲水性和耐污染性能得到显著提高,PVDF-PVP-Ag膜的纯水通量要优于PVDF基膜,通量恢复率达到93%;APS处理的PVDF-APS-Ag膜是通过化学脱氟反应改性而成,虽然PVDF-APS-Ag膜的亲水性也有提高,但是PVDF-APS-Ag膜的力学强度明显下降,以及其不均匀性导致Ag粒子聚集在膜表面,从而影响膜的耐污染性能。     

去甲肾上腺素聚合物的电化学沉积及性质研究

采用循环伏安法研究了金电极上去甲肾上腺素(NA)电氧化形成聚合膜的过程,结合电化学和红外光谱研究提出该聚合膜可能是聚吲哚膜的类似物,且该聚合膜具有较好的阳离子选择透过性。     

Relation between physical structure and electrical properties of diamond-like carbon thin films

Diamond-like carbon (DLC) belongs to very interesting materials used for a number of practical applications. Its properties strongly depend on the method of deposition and on the deposition parameters. In particular, the electrical properties of DLC films obtained by RF PCVD discharge depend substantially on the preparation conditions. Influence of deposition conditions on the physical structure and chemical content is discussed. Both the drift mobility of charge carriers and the electrical conductivity of DLC films strongly depend on deposition conditions. The electrical conductivity results are explained in terms of hopping mechanism. At the temperatures below 260 K, the hopping among states in a narrow band of states dominates; at the higher temperatures, the band-to-band transitions are suggested to occur. A model of the forbidden gap explaining the observed electrical properties of DLC films is proposed. Experimental results concerning the electrical conduction of DLC/Si heterostructures are also presented and discussed. The difference in the properties of DLC/n-Si and DLC/p-Si structures may suggest that the electron transport via localised states dominate in the investigated DLC films. Recombination lifetime of charge carriers in DLC films is measured using both dielectric spectroscopy and detection of decay of photocurrents. The lifetime is found to be of the order of 0.3–0.4 ms, which is quite long in comparison with classical doped silicon semiconductors.     

Properties of diamond-like carbon films on crystalline quartz and lithium niobate

One-micron thick DLC films are deposited on Y-X cut quartz and Y-cut lithium niobate substrates using a plasma-enhanced CVD technique. From the Raman spectra, we find that the films have a small intensity ratio of ‘D’ to ‘G’ peak, indicating a high carbon sp³/sp² ratio and high hardness characteristic. The effect of accelerating a surface acoustic wave by the DLC films has been confirmed by comparing two delayed signals from two near-by delay lines. One was coated with the DLC, while the other was kept as the free quartz or lithium niobate surfaces. It is observed that the one-micron thick DLC films are able to speed up SAW by 2.4% (at 198 MHz) for DLC/quartz and 2.5% (at 430 MHz) for DLC/lithium niobate samples, respectively.     

Nano-texture for a wear-resistant and near-frictionless diamond-like carbon

The effect of nano-scale surface texture on wear resistance of diamond-like carbon (DLC) films was studied using a reciprocating ball-on-flat tribometer in dry, humid, and liquid water environments. The nano-scale surface texture was produced by depositing ∼1 μm thick DLC films onto silicon substrates pre-textured with pyramidal wells and polystyrene spheres. The surface roughness of the textured DLC films was about 50 nm in both cases. The friction and wear behavior of the flat and nano-textured DLC films were tested with AISI 440C-grade stainless steel balls at a contact load creating about 360 nm deep Hertzian deformation which is significantly larger than the surface roughness. At this condition, nano-texturing did not affect the friction coefficient, but it significantly reduced the wear of DLC films in dry and humid nitrogen compared to flat DLC. In dry nitrogen, the nano-textured DLC films showed the ultra-low friction without substantial wear of DLC and deposition of thick transfer films onto the counter-surface. The wear reduction appeared to be related to the stress relief in the nano-textured DLC film. In liquid water, surface features on the nano-textured DLC films were diminished due to tribochemical oxidation and material removal at the sliding interface.     

Flexible diamond-like carbon film coated on rubber

Dynamic rubber seals are major sources of friction of lubrication systems and bearings, which may take up to 70% of the total friction. The solution we present is to coat rubbers with diamond-like carbon (DLC) thin films by which the coefficient of friction is reduced to less than one tenth. Coating rubber is very challenging because the film must be flexible and strongly adhered to the surface of rubber substrate. Our novel approach is depositing flexible DLC films on rubbers via self-segmentation. By making use of the substantial thermal mismatch between DLC film and rubber substrates a dense crack network forms in DLC films and contributes to flexibility. The size of film micro-segments can be tuned by varying the bias voltage of pulsed-DC plasma CVD, which governs the amplitude of the substrate temperature variation during deposition. The formation mechanism of crack network and its effect on the flexibility and friction of DLC film coated rubbers are scrutinized. This paper provides generic design rules for the deposition of flexible and ultra-low friction DLC films on rubber seals.     

Antibacterial activity of DLC and Ag–DLC films produced by PECVD technique

Diamond-like carbon (DLC) films have been the focus of extensive research in recent years due to its potential application as surface coatings on biomedical devices. Doped carbon films are also useful as biomaterials. As silver (Ag) is known to be a potent antibacterial agent, Ag–DLC films have been suggested to be potentially useful in biomedical applications. In this paper, DLC films were growth on 316L stainless steel substrates by using Plasma Enhanced Chemical Vapour Deposition (PECVD) technique with a thin amorphous silicon interlayer. Silver colloidal solution was produced by eletrodeposition of silver electrodes in distilled water and during the deposition process it was sprayed among each 25 nm thickness layer DLC film. The antibacterial activity of DLC, Ag–DLC and silver colloidal solution were evaluated by bacterial eradication tests with Escherichia coli (E. coli) at different incubation times. With the increase of silver nanoparticle layers in Ag–DLC, the total compressive stress decreased significantly. Raman spectra showed the film structure did not suffer any substantial change due to the incorporation of silver. The only alteration suffered was a slightly reduction in hardness. DLC and Ag–DLC films demonstrated good results against E. coli, meaning that DLC and Ag–DLC can be useful to produce coatings with antibacterial properties for biomedical industry.     

Characterization of non-uniform diamond-like carbon films by spectroscopic ellipsometry

Optical characterization of diamond-like carbon (DLC) films non-uniform in thickness is performed using spectroscopic phase-modulated ellipsometry. This characterization is based on new formulas for the associated ellipsometric parameters of thin films exhibiting a wedge-shaped thickness non-uniformity. These formulas express the associated ellipsometric parameters by means of the density of distribution of local film thickness. The spectral dependences of the optical constants of these non-uniform DLC films are expressed using the dispersion model based on parametrization of density of electronic states. It is shown that this model of the thickness non-uniformity provides a relatively good agreement between the experimental and theoretical data, indicating that the results of the optical characterization of the non-uniform DLC films are close to the correct results. Moreover, it is shown that the model of uniform thin films is unsuitable for the optical characterization of the non-uniform DLC films studied.     

Relationship between interlayer hardness and adhesion and pin-on-disc behaviour for fast atom beam source diamond-like-carbon films

The effect of interlayers of Ti, and Ti(C,N) on the adhesion, hardness and friction coefficient of DLC films deposited using a Fast Atom Beam (FAB) source has been studied. Values obtained for DLC films on top of interlayers were compared with those of DLC films directly deposited on Co-Cr substrates by both the FAB source and RF CVD techniques. The scratch test adhesion of such coatings can be classified in the following ascending order: DLC/Ti, DLC/no interlayer, DLC/Ti(C,N). The surface composite hardness is greatly improved by a Ti(C,N) interlayer. However, DLC films deposited on Ti(C,N) failed during the pin-of-disc test whilst those on Ti and without an interlayer exhibited low friction coefficients and excellent wear performance. An explanation is developed in order to explain the causes of film failure during the pin-on-disc test. For a given interlayer hardness, an adhesion threshold is required to survive the pin-on-disc test. The higher the hardness, the greater the required adhesion threshold, as interfacial shear stresses induced by the pin-on-disc are greater for hard surfaces, due to the smaller contact area.     

硬质合金刀具类金刚石涂层的摩擦磨损性能

以等离子体化学气相沉积技术在硬质合金刀具表面制备了类金刚石(DLC)涂层.研究了DLC涂层刀具和无涂层刀具的硬度,不同载荷、不同转速下两种刀具的摩擦磨损性能,以及在水润滑和油润滑条件下DLC涂层刀具的滑动摩擦行为.结果表明,DLC涂层刀具的平均硬度为2 099.9 HV,比无涂层刀具提高了48.3%;DLC涂层刀具的摩擦因数明显低于无涂层刀具,其磨损率随着载荷的增加而增大,随转速的增大而减小;油润滑比水润滑能更有效减缓摩擦作用.     

射频感应耦合化学气相沉积类金刚石薄膜的摩擦性能研究

采用射频感应耦合离子源（ICP）在硅基底上沉积了DLC薄膜,通过原子力显微镜（AFM）和拉曼光谱对DLC薄膜的表面形貌及结构进行了分析表征,用UTM-2摩擦磨损试验仪对薄膜的摩擦学性能进行了测试。结果表明,利用该方法沉积制备的DLC薄膜具有良好的减摩抗磨性能。     

Fabrication of DLC thin films with improved diamond-like carbon character by the application of external magnetic field

Diamond-like carbon (DLC) thin films were grown on Si-(100) substrates by a magnetically-assisted pulsed laser deposition (PLD) technique. The role of magnetic field on the structural, morphological, mechanical properties and deposition rate of DLC thin films has been studied. The obtained films were characterized by Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), field emission scanning electron microscopy (FE-SEM) and nanoindentation techniques. It was found that the diamond-like character, thickness and deposition rate of the DLC films increase in the presence of magnetic field. The films deposited under magnetic field exhibit a denser microstructure and smoother surface with lower surface roughness. Meanwhile, the mechanical properties of the magnetically processed DLC thin films experience an improvement, relative to the conventionally processed ones. It seems that the DLC films deposited under magnetic field can be better candidate for hard and wear resistance coating applications.