Arabian Journal of Chemistry (2019) 12 , 1186 – 1196
King Saud University
Arabian Journal of Chemistry
www.ksu.edu.sa www.sciencedirect.com
ORIGINAL ARTICLE
Nano-silica and SiO 2 /CaCO 3 nanocomposite prepared from semi-burned rice straw ash as modified papermaking fillers
Fatma A. Morsy a, * , Said M. El-Sheikh b , Ahmed Barhoum c
a Paper and Printing Lab., Chemistry Department, Faculty of Science, Helwan University, Cairo, Egypt b Nanostructure Materials Division, Advanced Materials Department, Central Metallurgical Research & Development Institute (CMRDI), P.O. Box 87, Helwan 11421, Cairo, Egypt c Department of Materials and Chemistry, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
Received 21 June 2014; accepted 17 November 2014 Available online 24 November 2014
KEYWORDS
Abstract Silica (SiO 2 ) nanoparticles and silica/calcium carbonate (SiO 2 /CaCO 3 ) core–shell nano- composites were prepared by sol–gel technique as fillers for papermaking application. Semi-burned rice straw ash (SBRSA), as waste material, was used to prepare the targeted fillers. Preparation of SiO 2 nanoparticles and SiO 2 /CaCO 3 nanocomposites was carried out using Na 2 SiO 3 solution that was prepared from SBRSA and CaCO 3 nanoparticles of 30–70 nm. The targeted SiO 2 /CaCO 3 nano- composites were prepared with different molar ratio of SiO 2 :CaCO 3 1:15, 1:10 and 1:5. The percentage of silica increased from 62.5% to 82.9% by thermal treatment of SBRSA at 800 C for 2 h. The pre- paredSiO 2 nanoparticles and SiO 2 /CaCO 3 nanocomposites were characterized by using XRD, XRF, TEM, FT-IR and Zeta potential. The results indicate that a pure semi-crystalline SiO 2 nanoparticle and semi-crystalline shell of SiO 2 coated CaCO 3 core particles were produced. The work extended also to investigate the effect of the prepared fillers on physical, mechanical and optical properties of paper. Application of the prepared SiO 2 nanoparticles and SiO 2 /CaCO 3 nanocomposites improved the optical properties of paper (brightness, whiteness and opacity) but it slightly reduced the mechanical properties when compared to commercial precipitated CaCO 3 (PCC) filler. The results showed that the retention of SiO 2 nano-particles was highly increased. The retention of the prepared nanocomposites increased along with increasing of SiO 2 :CaCO 3 molar ratio. ª 2014 The Authors. Production and hosting by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/).
Nano silica; Core–shell SiO 2 /CaCO 3 ; Semi-burned rice straw ash; Fillers; Paper properties
* Corresponding author. Tel.: +20 01019830883; fax: +20 2 25552468. E-mail address: fatma_a_morsy@yahoo.com (F.A. Morsy). Peer review under responsibility of King Saud University.
1. Introduction
In paper industry, finely-divided white mineral fillers are added to increase the paper brightness, opacity and improve the paper’s quality while having reduced costs by replacing the fibre (Gupta, 2007).The filler particles serve to fill the spaces
Production and hosting by Elsevier
http://dx.doi.org/10.1016/j.arabjc.2014.11.032 1878-5352 ª 2014 The Authors. Production and hosting by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/).
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