Interface and defects engineering for multilayer laser coatings

High-reflective multilayer laser coatings are widely used in advanced optical systems from high power laser facilities to high precision metrology systems. However, the real interface quality and defects will significantly affect absorption/scattering losses and laser induced damage thresholds of multilayer coatings. With the recent advances in the control of coating design and deposition processes, these coating properties can be significantly improved when properly engineered the interface and defects. This paper reviews the recent progress in the physics of laser damage, optical losses and environmental stability involved in multilayer reflective coatings for high power nanosecond near-infrared lasers. We first provide an overview of the layer growth mechanisms, ways to control the microstructures and reduce layer roughness, as well as the nature of defects which are critical to the optical loss and laser induced damage. Then an overview of interface engineering based on the design of coating structure and the regulation of deposition materials reveals their ability to improve the laser induced damage threshold, reduce the backscattering, and realize the desirable properties of environmental stability and exceptional multifunctionality. Moreover, we describe the recent progress in the laser damage and scattering mechanism of nodule defects and give the approaches to suppress the defect-induced damage and scattering of the multilayer laser coatings. Finally, the present challenges and limitations of high-performance multilayer laser coatings are highlighted, along with the comments on likely trends in future.     

Recent breakthroughs of antibacterial and antiviral protective polymeric materials during COVID-19 pandemic and after pandemic: Coating,packaging, and textile applications

The global epidemic owing to COVID-19 has generated awareness to ensuring best practices for avoiding the microorganism spread. Indeed, because of the increase in infections caused by bacteria and viruses such as SARS-CoV-2, the global demand for antimicrobial materials is growing. New technologies by using polymeric systems are of great interest. Virus transmission by contaminated surfaces leads to the spread of infectious diseases, so antimicrobial coatings are significant in this regard. Moreover, antimicrobial food packaging is beneficial to prevent the spread of microorganisms during food processing and transportation. Furthermore, antimicrobial textiles show an effective role. We aim to provide a review of prepared antimicrobial polymeric materials for use in coating, food packaging, and textile during the COVID-19 pandemic and after pandemic.     

制定企业标准，为企业发展保驾护航——论富阳市涂布白纸板生产企业制定企业标准的必要性

GB／T103354—2004《涂布纸和纸板涂布白纸板》对富阳市涂布白纸板生产实际存有不适用之处，为符合法律法规和企业自身发展需求，企业必须制定充分反映市场、用户和消费者要求的企业标准。     

Axisymmetric frictionless contact of functionally graded materials

The main interest of this study is a new method to solve the axisymmetric frictionless contact problem of functionally graded materials (FGMs). Based on the fact that an arbitrary curve can be approached by a series of continuous but piecewise linear curves, the FGM is divided into a series of sub-layers with shear modulus varying linearly in each sub-layer and continuous at the sub-interfaces. With this model, the axisymmetric frictionless contact problem of a functionally graded coated half-space is investigated. By using the transfer matrix method and Hankel integral transform technique, the problem is reduced to a Cauchy singular integral equation. The contact pressure, contact region and indentation are calculated for various indenters by solving the equations numerically. An erratum to this article can be found at     

Improved coating method for uniform polymer layer in infrared hollow fiber

An improved coating method was proposed in order to form a uniform polymer layer in the fabrication of cyclic olefin polymer-coated silver (COP/Ag) hollow fiber. A COP solution was flowed in a closed loop, in which the silver-coated tube was used as a part of the loop. Owing to the constant flowing speed of the COP solution and the airtight flowing environment, a COP layer was uniformly formed. The hollow fibers attain high performance and deliver multi-wavelength laser light from the infrared to the visible simultaneously. The method was successfully applied to the fabrication of practical hollow fibers with 2 m length for the near and mid-infrared lasers.     

JD树脂刻蚀及涂层的XPS研究

ＪＤ光学树脂表面刻蚀过程的ＸＰＳ研究表明，引进树脂遥ＣＯＨ，Ｃ＝Ｏ，Ｃ－ＳＯ３Ｈ，ＣＯＯＨ等基因随刻蚀温度的提高或时间的延长而增加，对其相对含量进行了计算，固化后的耐磨涂层具有ＳｉＯ２结构，ＪＤ板材的最佳刻蚀条件为２０℃，２０ｍｉｎ。     

Sol–gel preparation and properties of hydroxypropylcellulose–titania hybrid thin films

Hydroxypropylcellulose (HPC)–titania hybrid thin films were prepared by sol–gel method where titanium tetraisopropoxide Ti(OC₃H₇ ⁱ )₄ was hydrolyzed under acidic conditions in the presence of HPC, followed by dip-coating and drying at 120 °C for 24 h. The viscosity average molecular weight of HPC was 55,000–70,000 or 110,000–150,000, and the TiO₂/(HPC + TiO₂) mass ratio ranged from 0 to 1, which was calculated on the assumption that all Ti(OC₃H₇ ⁱ )₄ is converted into TiO₂. The films were 0.35–1.0 μm thick, transparent in visible region and opaque in ultraviolet (UV) region, where the optical absorption coefficient in UV region increased with increasing titania content. The refractive index increased with increasing titania content, ranging from 1.6 to 1.8 for the hybrid thin films. The pencil hardness increased from 6B to 5H, the durability in hot water significantly increased and the contact angle of water on films increased from 35° to 89° with increasing titania content. Crack-free films could be deposited on organic polymer substrates irrespective of titania or HPC contents, where cracking did not occur at higher HPC contents even when the substrate was bent.     

Enhancement of the light-scattering ability of coatings by using hollow pigments

The light-scattering properties of coatings based on monodisperse polymeric spheres of two different diameters (ca 0.5 and 1 m) were evaluated from reflectance measurements as a function of the wavelength from 400 to 700 nm. Some of these plastic pigments were hollow and it was noted that these particles gave coatings with a greater light-scattering ability than coatings based on solid particles of a similar size. It was possible to estimate the contribution of the internal pores to the scattering ability of the coating layers by saturating the layers with an oil of a refractive index similar to that of the polymeric pigment particles. A simple model accounting for the scattering provided by the internal pores of the hollow particles is suggested. The agreement between the experimental results and the prediction of the model is fair. It was noted that the light scattering coefficient of the coatings increased when the external diameter of their constituent hollow particles increased from ca 0.5 to 1 m.     

Coating Carbon Nanotubes with Europium Oxide

Carbon nanotubes (CNTS) coating with europium oxide by a simple method is reported in this letter for the first time. The CNTS were refluxed in a solution of nitric acid containing europium nitrate, and the pH value was subsequently ajusted with ammonia solution. At last, the mixture was filtered and annealed. The TEM micrograph showed that the CNTS were covered with a uniform thin layer with thickness of about 15 nm. The XRD results revealed that the CNTS were coated with europium oxide.     

等离子体聚合及其聚合物的应用

本文着重综述了烃,含氮、氧的有机化合物,碳氟化合物以及有机硅化合物的等离子体聚合。同时还系统地介绍了等离子体聚合物在制备反渗透膜、分离膜、材料表面的涂层等方面的国内外的最新研究成果。