Carbohydrate Polymers 274 (2021) 118626 Available online 1 September 2021 0144-8617/© 2021 Elsevier Ltd. All rights reserved. LBL generated fre retardant nanocomposites on cotton fabric using cationized starch-clay-nanoparticles matrix Zeeshan Ur Rehman a , Seok-Hwan Huh a , Zakir Ullah b , Ye-Tang Pan c , David G. Churchill b, ** , Bon Heun Koo a, * a College of Mechatronic Engineering, Changwon National University, Changwon, Gyeongsangnam-do 51140, Republic of Korea b Department of Chemistry, Molecular Logic Gate Laboratory, Korea Advanced Institute of Science and Technology (KAIST), Republic of Korea c National Engineering Technology Research Center of Flame Retardant Materials, School of Materials Science & Engineering, Beijing Institute of Technology, Beijing 100081, PR China A R T I C L E INFO Keywords: Fire retardant Nanoparticle Ammonium centers Pyrolysis TiO 2 Vermiculite Cotton Ionization ABSTRACT In this work, starch–clay–TiO 2 -based nanocomposites were deposited on cotton fabric through layer-by-layer (LBL) process and their effect on the fame retardancy, inhibition of pyrolysis and combustion processes were discussed in details. Polyelectrolyte solutions/suspensions of cationized starch and VMT (vermiculite)/TiO 2 nanoparticles were used to deposit these nanocomposites in the form of multi-layered coatings (5, 7, 10 and 15 bilayers). Uniform fabric coverage and presence of electrolytes was imaged by scanning electron microcopy (LV- SEM), attenuated total refectance Fourier transform infrared spectroscopy (ATR-FTIR) and EDX characteriza- tions. The greatest pyrolysis reduction was found for the StVT-7 sample (7 bilayers); ~30% and 21%, based on microscale combustion calorimetry (MCC) and thermogravimetric analysis (TGA). When using MCC, the improved values of the PHRR ~ 193 W/g, THR ~ 10.7 kJ/g), HRC ~ 390 J/g∙K and LOI ~ 22.2% were found for the StVT-7 sample which was strongly supported by the UL-94 test. 1. Introduction Cotton is one of the most basic necessities for human life, and thus it is used and applied in various commodities, bulk materials and textiles, ranging from the 2nd generation to the 4th generation industrial prod- ucts. However, the major drawbacks with cotton fabric is its low limiting oxygen index (LOI) and combustion temperature (360–425 ◦ C), which makes it highly fammable (Wakelyn, Bertoniere, French, & Thibo- deaux, 2007). Cotton-based products burn swiftly once they are ignited, and the fame triggered by the ignition can cause fatal burns within 15 s of ignition! (Oulton, 1995). Extensive injuries, loss of life and property damages are issues that drive the quest for new materials. There is an increased demand for the fre protection of commercial cotton products, in particular those used in frefghter apparel, institutional draperies, upholstery items, commercial carpets, transportation equipment, mili- tary garments and beddings (Abou-Okeil, El-Sawy, & Abdel-Mohdy, 2013). However, unlike synthetic fbers, fame retardancy of natural cotton fbers cannot modifed by incorporating fame retardant additives into their chemical backbones. Hence, various surface modifcation methods have been applied, such as ultraviolet curing of functional monomers and pre-polymers (Yuan, Xing, Zhang, Song, & Hu, 2012) surface grafting treatment (Reddy, Agathian, & Kumar, 2005), sol–gel process to form a coating layer directly on cotton (Alongi & Malucelli, 2012), fame retardant fnishing treatment (Xie, Gao, & Zhang, 2013), plasma treatments (Alongi, Carosio, & Malucelli, 2014), and layer-by- layer (LBL) assembly to help impart fre-retardant properties to the cotton (Holder, Smith, & Grunlan, 2017; Xiaoqing, Zhiwei, Xiaohong, & Zhijun, 2018; Kundua, Zhiwei, Songa, & Hua, 2020; Simone, Kolibaba, & Grunlan, 2020; Davesne, Jimenez, Samyn, & Serge, 2021; Koklukaya, Oruc, Karlsson, Carosio, & Wagberg, 2021). Among these deposition techniques, layer-by-layer deposition method is a relatively new coating preparation method by which envi- ronmental friendly and novel fame resistant materials can be deposited onto cotton fabric and other fre vulnerable materials. In the last two decades layer-by-layer assemblies have been studied comprehensively to produce multifunctional thin flms in the micrometer thickness range * Corresponding author. ** Co-corresponding author. E-mail addresses: david.churchill.korea@gmail.com (D.G. Churchill), bhkoo@changwon.ac.kr (B.H. Koo). Contents lists available at ScienceDirect Carbohydrate Polymers journal homepage: www.elsevier.com/locate/carbpol https://doi.org/10.1016/j.carbpol.2021.118626 Received 5 April 2021; Received in revised form 25 August 2021; Accepted 27 August 2021