"空气清新涂料"的开发与研究

通过纯丙乳液的制备、抗菌助剂的选择、合适成膜助剂、不含有毒有害重金属颜填料的选择以及负离子素的使用机理分析研制的“空气清新涂料”，集纯丙烯酸内墙涂料的耐水、耐擦洗、耐候性好、附着力优异等产品综合性能与长期释放抗菌成分及永久释放负离子，使室内空气负离子浓度提高至500～1000个／cm^3以上等各类性能于一体，产品性能达到国家强制性标准GB18582、国家推荐标准GB／T9756及产品抗菌、释放负离子企业标准。属于当今流行的功能性高档装饰材料，市场前景广阔。     

重力下水道中混凝土的微生物诱导腐蚀及防护涂层(英文)

Microbiologically induced corrosion of concrete(MICC) and its protective coatings has a high economic impact on sewer maintenance and rehabilitation.A better understanding of the micro-organisms and the biogenic acids that are generated in the sewer is essential in controlling the corrosion of concrete pipes and protective coatings.The role of succession of micro-organisms growth in the corrosion of concrete and protective coatings was evaluated in this study.Examination of various sewer pipe materials exhibiting various extents of degradation,including concrete,cement based and epoxy based coating revealed the presence of both organic and biogenic sulphuric acids.This reflects the activity of fungi and the thiobacilli strains.Organism growth and metabolism were strongly related to the substrate pH.Fungi were found to grow and metabolise organic acids at pH from 2.0-8.0.Whilst the thiobacilli strains grew and generated sulphuric acids at pH below 3.0.The successive growth of the organisms provides an important bearing in developing improved strategies to better manage sewers.     

Cohesive strength of nanocrystalline ZnO:Ga thin films deposited at room temperature

In this study, transparent conducting nanocrystalline ZnO:Ga (GZO) films were deposited by dc magnetron sputtering at room temperature on polymers (and glass for comparison). Electrical resistivities of 8.8 × 10-4 and 2.2 × 10-3 Ω cm were obtained for films deposited on glass and polymers, respectively. The crack onset strain (COS) and the cohesive strength of the coatings were investigated by means of tensile testing. The COS is similar for different GZO coatings and occurs for nominal strains approx. 1%. The cohesive strength of coatings, which was evaluated from the initial part of the crack density evolution, was found to be between 1.3 and 1.4 GPa. For these calculations, a Young's modulus of 112 GPa was used, evaluated by nanoindentation.     

Preparation of emulsifier-free acrylate cross-linkable copolymer emulsion and application in coatings for controlling indoor humidity

Indoor humidity has an important influence on our lives. Too high relative humidity (RH > 60 %) can cause the metal surface corrosion, electrical insulation fall, material deformation and so on. On the contrary, when the moisture content is too low (RH < 40 %), it causes skin chapping, decrease in respiratory system resistance, static electricity, etc. The humidity controlling coating is a kind of composite that controls the humidity of materials. In this study, the emulsifier-free acrylate copolymer emulsion (EF-AAC) containing ketocarbonyl and carboxyl groups was synthesized and the humidity controlling coating (EF-AAC-C) was prepared by EF-AAC, adipic dihydrazide (ADH) and porous fillers. The different proportions and the contents of KPS, NaHCO₃, and the effects of polymerization time and reaction temperature on the stability of emulsion were investigated. The different ratios of fillers/emulsion and ADH/diacetone acrylamide for water resistance of coatings were also studied. Moreover, the structure of emulsifier-free acrylate copolymer was characterized by FTIR and TGA techniques. The particle morphologies were measured by transmission electron microscopy and dynamic light scattering. It showed that the distribution of emulsion particle size was narrow and uniform. The properties of humidity controlling coatings were studied with particular attention to the effects of the humidity controlling. Meanwhile, the water absorption of humidity controlling coatings was up to 260 %. The humidity controlling coatings revealed excellent properties of humidity sensitivity and humidity retention because of the composite porous structure due to fillers with emulsifier-free acrylate copolymer. The mechanism of breathing water molecules in obtained coatings was suggested and the composite could be widely used as indoor coatings for controlling humidity.     

Recent Advances in Metal-Based Antimicrobial Coatings for High-Touch Surfaces

International interest in metal-based antimicrobial coatings to control the spread of bacteria, fungi, and viruses via high contact human touch surfaces are growing at an exponential rate. This interest recently reached an all-time high with the outbreak of the deadly COVID-19 disease, which has already claimed the lives of more than 5 million people worldwide. This global pandemic has highlighted the major role that antimicrobial coatings can play in controlling the spread of deadly viruses such as SARS-CoV-2 and scientists and engineers are now working harder than ever to develop the next generation of antimicrobial materials. This article begins with a review of three discrete microorganism-killing phenomena of contact-killing surfaces, nanoprotrusions, and superhydrophobic surfaces. The antimicrobial properties of metals such as copper (Cu), silver (Ag), and zinc (Zn) are reviewed along with the effects of combining them with titanium dioxide (TiO₂) to create a binary or ternary contact-killing surface coatings. The self-cleaning and bacterial resistance of purely structural superhydrophobic surfaces and the potential of physical surface nanoprotrusions to damage microbial cells are then considered. The article then gives a detailed discussion on recent advances in attempting to combine these individual phenomena to create super-antimicrobial metal-based coatings with binary or ternary killing potential against a broad range of microorganisms, including SARS-CoV-2, for high-touch surface applications such as hand rails, door plates, and water fittings on public transport and in healthcare, care home and leisure settings as well as personal protective equipment commonly used in hospitals and in the current COVID-19 pandemic.     

The Measurement of Residual Strains Within Thermal Barrier Coatings Using High-Energy X-Ray Diffraction

The residual strains through the entire thickness of the zirconia layer of pristine and heat-treated thermal barrier coatings (TBCs) were mapped to help elucidate the failure mechanisms of TBCs. The strains were measured using 80.72 keV synchrotron radiation and a transmission geometry. The heat-treated TBC showed that a compressive strain formed in the zirconia layer of the TBC on cooling but this strain was diluted and reversed by the oxidation-driven expansion of the underlying metals. It also showed large (0.0024) out-of-plane tensile strains in the zirconia layer just above its interface with a thick underlying oxide layer.     

电镀钨合金抽油杆耐硫化氢腐蚀研究

采用直流电镀法,在30CrMo抽油杆表面分别制备了单层Fe–Ni–W、Ni–W–P、Ni–W和双层Fe–Ni/Ni–W–P合金。室温下,将上述镀覆了钨合金的抽油杆浸泡在饱和H2S水溶液中30d,采用失重法、扫描电镜、X射线衍射等方法对其耐腐蚀进行了分析。结合阳极极化曲线测量,探讨了双层Fe–Ni/Ni–W–P镀层的耐蚀机理。实验结果表明:钨合金镀层使抽油杆的耐腐蚀性得到了显著提高,从而可延长其使用寿命。双层Fe–Ni/Ni–W–P合金镀层的耐蚀性最好,Fe–Ni层与Ni–W–P层之间的电势差达到了150mV,起到很好的保护作用。     

In situ measurement of water at the organic coating/substrate interface

In situ and quantitative information on the water layer at the organic coating/substrate interface is crucial for understanding and preventing the failure of organic coating systems. A technique, based on a two-layer model derived rigorously from internal reflection theory, has been developed for measuring in situ the thickness and amount of the water layer at the organic coating/substrate interface. The technique gives new insight into the processes by which water degrades the coating/substrate bonds. In this technique, a transparent or an opaque organic coating of sufficient thickness is applied to an internal reflection element (IRE) with or without a thin metallic film, which is used as the substrate. A water chamber is attached to the organic-coated specimen. After adding water to the chamber, Fourier transform infrared-multiple internal reflection (FTIR-MIR) spectra are taken automatically at specified time intervals without disturbing the specimens or the instrument. Water uptake in the coating and FTIR-MIR spectra of water on the coating-free substrate are also used for the analysis. Examples of clear and pigmented coatings on untreated and treated substrate surfaces are given to demonstrate the technique. Results of water accumulation at the coating/iron interface with and without applied electrical potentials are given. In addition to measuring water at the coating/substrate interface, the technique provides a means for studying the transport of water through a coating adhered to a substrate. Information on water at the interface and its transport properties through coatings applied to a substrate is valuable for interpreting corrosion, blistering and delamination of organic coating systems, and for developing models for use in predicting the serivce lives of protective coatings.     

Elastica bend testing of the effective interfacial shear strength and critical deformation strains of brittle coatings on ductile substrates

An elastica bend test is described that provides a rapid, convenient, and reproducible means for examining the interfacial delamination of brittle coatings on ductile substrates. By bending a coated strip into a half-loop and examining the microscopic cracking that is observed on the sample surface as the loop size decreases, information is obtained about the characteristic initial, mean, and final strains _i, _m and _f that describe the distribution in strength of the coating. By measuring the distance between the cracks at high strains, we obtain an estimate of the interfacial shear strength τ.     

Facile preparation and good performance of nano-Ag/metallocene polyethylene antibacterial coatings

Metallocene polyethylene/nano-silver coatings were prepared by a facile air-spray method on polymer films. Different from the prevailing strategy to endow polyethylene with antibacterial performance, we used metallocene polyethylene sol and nano-silver as a precursor to deposit coatings on polymers at a relatively low operating temperature. Antibacterial coatings with excellent mechanical properties, water resistance, and low silver release were achieved. The composite coatings were examined in terms of surface characteristics, mechanical properties, and antibacterial activity against two representative bacterial strains including Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The composite coatings exhibited favorable microstructure, good mechanical properties, and suitable crystallinity. The antimicrobial tests indicated that the fabricated composite coatings showed promising antibacterial activity against E. coli and S. aureus. Furthermore, Ag ions released by the composite coating after 30 days were under 1.2 ppb. These results indicated a promising prospect of the composite coating for wide antibacterial applications.     

弱极化法测评大功率二次雾化电弧喷铝涂层的腐蚀防护寿命

利用弱极化原理,通过腐蚀速率测量仪测量大功率二次雾化电弧喷铝涂层的腐蚀电位和腐蚀电流密度,计算其深度腐蚀速率,时电弧喷铝涂层的防腐寿命进行评估,获得了不同厚度电弧喷铝涂层所对应的防护寿命,确定了具有不同防护寿命的复合涂层的最佳防腐设计方案.讨论了该法存在的问题.指出电弧喷铝复合涂层的防护寿命不仅取决于涂层系统的选择及其内在质量,而且与腐蚀环境和防腐蚀涂装质量、工程养护质量密切相关,应用中须根据已用工程金属涂层的实际防护寿命对其进行修正.     

铌合金涂覆前化学氧化工艺

铌合金因其优异的性能被广泛用于航天航空工业。但在使用过程中,因表面涂覆涂层经常起泡破裂使产品寿命及用途受限。针对常用铌合金涂覆过程中出现的问题,通过生产实践及验证,总结出通用的铌合金涂覆前处理化学氧化工艺。该工艺主要通过除油、预浸蚀、酸洗、出光及化学氧化等工序对铌合金材质的零件进行化学处理,最终达到提高涂层性能和外观的要求。     

Failure of coatings over joints and gaps: finite-element models

Painting over joints and the narrow gaps around fasteners is extremely common. When the joint or gap is stressed, the gap opens and the coating over it is subject to very large strains that may immediately or eventually cause it to fail and thus permit corrosion, etc. Improving the design or selection of coatings to overcome this problem requires quantification of the imposed elongation of the coating. A simple coated butt joint geometry, in tension and in bending, is modeled by finite-element analysis to examine how coatings of different modulus respond to the opening of a joint, particularly showing regions where strain distributions may provoke failure. More loci of possible initial failure occur when the gap is filled by a material that is different from the coating over the gap because there is an added interface.     

Effect of Saccharides Coating on Antibacterial Potential and Drug Loading and Releasing Capability of Plasma Treated Polylactic Acid Films

More than half of the hospital-associated infections worldwide are related to the adhesion of bacteria cells to biomedical devices and implants. To prevent these infections, it is crucial to modify biomaterial surfaces to develop the antibacterial property. In this study, chitosan (CS) and chondroitin sulfate (ChS) were chosen as antibacterial coating materials on polylactic acid (PLA) surfaces. Plasma-treated PLA surfaces were coated with CS either direct coating method or the carbodiimide coupling method. As a next step for the combined saccharide coating, CS grafted samples were immersed in ChS solution, which resulted in the polyelectrolyte complex (PEC) formation. Also in this experiment, to test the drug loading and releasing efficiency of the thin film coatings, CS grafted samples were immersed into lomefloxacin-containing ChS solution. The successful modifications were confirmed by elemental composition analysis (XPS), surface topography images (SEM), and hydrophilicity change (contact angle measurements). The carbodiimide coupling resulted in higher CS grafting on the PLA surface. The coatings with the PEC formation between CS-ChS showed improved activity against the bacteria strains than the separate coatings. Moreover, these interactions increased the lomefloxacin amount adhered to the film coatings and extended the drug release profile. Finally, the zone of inhibition test confirmed that the CS-ChS coating showed a contact killing mechanism while drug-loaded films have a dual killing mechanism, which includes contact, and release killing.     

A modelling study of the visco-elastic behaviour of polyester-based coil coatings

The time and temperature dependence of the mechanical response of a series of polyester-based hexa(methoxymethyl)melamine cross-linked coil coatings was investigated. Small strain experiments such as dynamic mechanical analysis and stress relaxation are used to determine the parameters required for time–temperature superposition and for the determination of the relaxation spectra of the materials. Tensile tests at a range of temperatures and strain rates are used to show that time–temperature superposition can be successfully extended to cover the ultimate properties of the paints (i.e. those at fracture). Finally, a hybrid visco-elastic/hyper-elastic model is used to capture the tensile stress–strain response of the paints. The success of the visco-elastic component of the model is demonstrated at strains up to 5%, while at larger strains the model behaves best when the experimental behaviour of the material approaches that of rubber, with the fit becoming worse when the mechanical response is that of a ductile plastic.     

Poly(dimethylsiloxane) coatings for controlled drug release. I. Preparation and characterization of pharmaceutically acceptable materials

The basic technology for forming crosslinked elastomers by the end linking of low molecular weight hydroxyl‐terminated poly(dimethylsiloxane) (PDMS) with tetraethoxysilane (TEOS) was modified to make it suitable for preparing coatings for controlled drug release. The requirements for this application included establishing conditions for the end linking that did not require the usual toxic tin or platinum catalysts; preparation of emulsions of small PDMS network particles that had extensive shelf‐lives and that could be coalesced into cohesive thin films or coatings; and the determination of the conditions to make such coatings pinhole free, mechanically robust, and of sufficient thermal stability for coating procedures at elevated temperatures. The approach taken consisted of preparing water‐based emulsions of the PDMS with sodium lauryl sulfate and restriction of the pH of the system to the acidic range with HCl. Evaporation of water from the emulsions resulted in elastomeric free‐standing films of the PDMS that were characterized using stress–strain isotherms in elongation and equilibrium swelling in toluene, both at room temperature. The mechanical properties of the films were found to improve with an increasing molar ratio of HCl/TEOS and an increase in the amount of TEOS (giving increased degrees of crosslinking). Conditions for the optimization of the thermal stabilities as gauged by thermogravimetic analysis were established, including beneficial effects from the introduction of the crosslinks. Scanning electron microscopy showed that the predominant morphology was void‐free films with very small, homogeneously dispersed silica particles from the hydrolysis of some of the TEOS. Additional work should be facilitated by the mechanisms for the crosslinking suggested by the experimental results. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 658–666, 2003     

Film Structure and Adhesion

Paint films although attached to a substrate on one side only may be subjected to stresses, comparable to those in structural adhesives. These stresses result from shrinkage during film formation and subsequent ageing, mechanical strains, relative thermal movements of film and substrate and from osmotic pressure due to soluble material under or within the film. The adhesive strength required to prevent detachment varies from very little for weak, highly porous coatings to 10,000 lb/in² for tough coatings of high elastic modulus. Generally, adhesive strength both to the substrate and between coats in a paint system must exceed cohesive strength, under the conditions when failure is likely to develop. Dispersion and other forces, such as hydrogen bridging, between coatings and clean metal substrates should suffice to ensure adhesion but most practical surfaces carry contaminants, which interfere with wetting and intimacy of contact. Solvents and other low molecular weight components may also provide a weak interfacial layer, at least for a period after application. Modification of polymer structure to improve contaminant displacement and to increase polymer/substrate interaction forces, for example by the introduction of polar substituent or end groups will be discussed and potentialities of adhesion-promoting surface treatments reviewed.     

Film Structure and Adhesion

Paint films although attached to a substrate on one side only may be subjected to stresses, comparable to those in structural adhesives. These stresses result from shrinkage during film formation and subsequent ageing, mechanical strains, relative thermal movements of film and substrate and from osmotic pressure due to soluble material under or within the film. The adhesive strength required to prevent detachment varies from very little for weak, highly porous coatings to 10,000 lb/in² for tough coatings of high elastic modulus. Generally, adhesive strength both to the substrate and between coats in a paint system must exceed cohesive strength, under the conditions when failure is likely to develop. Dispersion and other forces, such as hydrogen bridging, between coatings and clean metal substrates should suffice to ensure adhesion but most practical surfaces carry contaminants, which interfere with wetting and intimacy of contact. Solvents and other low molecular weight components may also provide a weak interfacial layer, at least for a period after application. Modification of polymer structure to improve contaminant displacement and to increase polymer/substrate interaction forces, for example by the introduction of polar substituent or end groups will be discussed and potentialities of adhesion-promoting surface treatments reviewed.     

地坪涂料 后起之秀

地坪涂料在我国只有20多年的历史，但发展十分迅速。本文简要介绍地坪涂料的发展过程，分类和性能要求，一般施工方法，重要的地坪涂料品种及其发展趋势。     

高氯化聚乙烯在防腐涂料中的应用研究

研究了固相法涂料用高氯化聚乙烯树脂的制备及其在防腐涂料中的应用。结果表明,适当降低原料高密度聚乙烯（ＨＤＰＥ）的分子量,产物高氯化聚乙烯（ＨＣＰＥ）树脂可直接用于涂料配制;调节ＨＤＰＥ的分子量及ＨＣＰＥ的氯含量,涂料粘度可在较大范围内变化。ＨＣＰＥ涂料的性能远优于过氯乙烯涂料而与氯化橡胶涂料相当,是替代氯化橡胶涂料的理想物质。