Research Article Cite This: ACS Sustainable Chem. Eng. XXXX, XXX, XXX−XXX
pubs.acs.org/journal/ascecg
Dendritic Silica Particles with Well-Dispersed Ag Nanoparticles for Robust Antireflective and Antibacterial Nanocoatings on Polymeric Glass Yulu Wang,† Yabin Wang,‡ Xiaoyu Li,§ Jianqiang Li,§ Lei Su,† Xueji Zhang,† and Xin Du*,†
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Research Center for Bioengineering and Sensing Technology, Beijing Key Laboratory for Bioengineering and Sensing Technology, Department of Chemistry & Biological Engineering, University of Science & Technology Beijing, Beijing 100083, P. R. China ‡ Shaanxi Key Laboratory of Chemical Reaction Engineering, College of Chemistry and Chemical Engineering, Yan’an University, Yan’an, Shaanxi 716000, P. R. China § National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academic of Sciences, Beijing 100190, China S Supporting Information *
ABSTRACT: Robust nanocoatings with both antireflective (AR) and antibacterial properties for transparent plastic substrates are not only significantly attractive in science but also urgently needed in wide applications. However, it is still a great challenge to realize the fabrication of this kind of multifunctional nanocoatings on plastic/polymer substrates. In this work, a series of single-particle-layered nanocoatings were prepared by partially embedding dendritic fibrous nanosilica (DFNS) with well-dispersed Ag nanoparticles (NPs) onto the surface of poly(methyl methacrylate) (PMMA) polymeric glass via organic vapor treatment. The optimal coated PMMA slide not only exhibits the enhanced transmittance with the highest one of 94.5% but also shows excellent antibacterial activity (at least killing 80% bacteria) toward both Gram-positive Staphylococcus aureus and Gramnegative Escherichia coli. Moreover, both long-term ultrasonic processing and pencil hardness tests proved strong adhesion of particles on PMMA substrate due to partial embedding. This work provides an exploration approach to construct the multifunctional nanocoatings on polymeric substrates for potential applications in various optical devices and daily touch plastic glass. KEYWORDS: Dendritic fibrous nanosilica, Nanocoating, Antibacterial, Antireflection, Plastic substrates
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resistance.11−15 However, it usually needs the relatively complicated steps to remove the pore-forming agents and strengthen the adhesion between nanocoating and substrate. In addition, much effort has been devoted to fabricate antibacterial nanocoatings by introducing antibacterial agents to kill bacteria and/or creating nanostructures to decrease the bacterial adhesion.16−27 However, high antibacterial activity of nanocoatings often results in the remarkable decrease of transparency.16−27 Furthermore, it is of great significance to achieve the smart integration of AR (enhanced transmittance) and antibacterial dual properties into nanocoatings for transparent plastic substrates. However, it is still a huge challenge to skillfully realize the preparation of this kind of robust AR and antibacterial nanocoatings. Wang and co-workers prepared Ag NPs-involving mesoporous silica thin films with AR and antibacterial dual-
INTRODUCTION Up until now, transparent polymeric substrates have been widely used in daily life such as windows, screens, eyeglass lenses, optical apparatuses, optoelectronics, etc. due to their excellent physicochemical properties such as high transparency, high flexibility, lightweight, and robustness. However, reflection at the interfaces between transparent polymeric substrates and air will cause undesirable visual effects and optical loss, and the bacterial pollution at the substrate surface may result in the infection risk and concomitant health-care problem. Therefore, the design and fabrication of antireflective (AR) or antibacterial nanocoatings/films on polymer substrates has recently become a fast-growing topic owing to strong demand in various touch screens and optical apparatuses for medical and cutting-edge use.1−6 Two main strategies are employed to achieve antireflection on the surfaces of polymer substrate currently. One is by reshaping the surface to create porous or well-defined periodic nanostructures.7−10 However, their main shortcoming is their poor wear resistance. The other is by forming the ceramic-based AR porous nanocoatings with excellent wear © XXXX American Chemical Society
Received: June 5, 2018 Revised: September 6, 2018
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DOI: 10.1021/acssuschemeng.8b02617 ACS Sustainable Chem. Eng. XXXX, XXX, XXX−XXX
Research Article
ACS Sustainable Chemistry & Engineering
Figure 1. Schematic illustration of (a) fabrication of DFNS-NH2@Ag NPs, (b) construction of particulate nanocoatings of DFNS-NH2@Ag NPs partially embedded in the PMMA slides, and (c) robust antireflective and antibacterial properties.
function on glass substrate by using silica sols with surfactant and Ag NPs.18 The existence of surfactant resulted in the inevitable calcination under high temperatures, which is not suitable for polymer substrates. Jeong’s group fabricated a regular surface with hexagonal nanolattices with a period of ∼300 nm and an aspect ratio of ∼3.0 on the PMMA surface by nanoimprint lithography, which showed a low reflectance of
