Research Article Characterization of Nanosilica/Low-Density Polyethylene Nanocomposite Materials Malek Alghdeir , Khaled Mayya, and Mohamed Dib Applied Physics Department, Higher Institute for Applied Sciences and Technology, Damascus, Syria Correspondence should be addressed to Malek Alghdeir; malekghdeir@yahoo.com Received 2 October 2018; Revised 22 November 2018; Accepted 19 December 2018; Published 20 March 2019 Guest Editor: Chandragiri V. Reddy Copyright © 2019 Malek Alghdeir et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Six ratios of nanosilica particles were employed to fabricate low-density polyethylene (LDPE) composites using melt mixing and hot molding methods. Several composite films with different ratios (0.5, 1, 2.5, 5, 7.5, and 10 wt%) of SiO 2 were prepared. The obtained composite films were identified and characterized by Fourier-transform infrared spectroscopy (FTIR) and ultraviolet-visible spectroscopy (UV-VIS). At a specific mixing ratio, far infrared radiation transmittance was prohibited while the ultraviolet-visible transmittance is allowed; this will be explained in detail. Optical measurements show that the composite films prevent the transmission of IR radiation near 9 μm and allow UV-VIS transmission during sun-shining time. The mechanical behaviour of a nanosilica-reinforced LDPE composite was studied using tensile tests. The addition of 1 wt% nanosilica has successfully enhanced the mechanical properties of the LDPE material. 1. Introduction Polymeric materials are widely used in food packaging and in greenhouses. Typical examples of such materials are polypropylene (PP), polyethylene (PE), and polyethylene terephthalate (PET) [1, 2]. During the past years, much effort has been devoted to polymer nanocomposites [3]. Polymer nanocomposites often show excellent mechanical properties compared to the traditional composites at a lower loading of the nanopar- ticles [4]. So far, a few researches have studied the effects of different nanoparticles on the performances of composite materials such as nanosilica [3]. The excellent performance of silica film has attracted attention in academia and indus- try due to its antiresistance, hardness, corrosion resistance [5], dielectric properties [6], optical transparency, etc. [7]. Silica as a thin film is widely used to improve the surface properties of materials. This is why silica thin films are used in many fields as in antireflection coating film field [8]. In the packaging industry, silica films are used as barrier layers in polymer packaging materials. Most of the modern pack- aging materials do not provide an efficient barrier against the permeation of gases. This leads to food and drinks getting rotten quickly. Because of this, a silica film deposited on the surface of the polymer packaging becomes popular and indispensable. Besides, silica films can be also used as corrosion protective layers of metals. Because of the univer- sal application of silicon dioxide films in various fields, the preparation of silica with high quality is always an important aim of scientific research [9]. Lately, a number of different barrier technologies were being developed. Theoretically, a barrier function can be inserted into a plastic-based material via two different means: either by mixing a barrier material into the base polymer or by coating a layer of the barrier material on the polymer surface [10, 11]. The traditional method of preparing polymer/silica composites was direct mixing of the silica into the polymer. The mixing could be done by melt blending and solution blending. The main difficulty in the mixing process is the effective dispersion of the silica nanoparticles in the polymer matrix, because they usually tend to agglomerate [12]. This work represents the results of optical and thermal experiments on LDPE mixed with nanosilica particles at different ratios (0.5, 1, 2.5, 5, 7.5, and 10 wt%). The aim is to achieve a nanocomposite that prevents the transmittance Hindawi Journal of Nanomaterials Volume 2019, Article ID 4184351, 8 pages https://doi.org/10.1155/2019/4184351