ASIAN JOURNAL OF CHEMISTRY ASIAN JOURNAL OF CHEMISTRY https://doi.org/10.14233/ajchem.2018.21467 INTRODUCTION Nanoparticles are defined as submicron-size solid between 100 to 500 nm that can be either biodegradable or non-bio- degradable [1]. Nanoparticles can be constructed from various materials (e.g. polymers, lipids, metals, magnetic) and widely utilized in various industrial application like optical [2], catalyst [3], thermal [4], electrical [5], mechanical [6] and magnetic function [7]. In particular, polymeric nanoparticles have received great attention on account of their versatility in which they can host a wide range of active components including chemothera- peutics, contrast agents, proteins and nucleic acids, for various bio-medical applications [8]. The criteria for the ideal polymeric nanoparticles espe- cially in the development of biomedical fields should be easy to synthesize, inexpensive, biocompatible and biodegradable, non-toxic and water soluble [9]. Hydrophilic polymer nano- particles are the type of polymer chain that contains substitution of hydrophilic groups at the backbone either from anionic, cationic or amphoteric. This type of polymer can be divided into two main types, synthetic and natural. Nowadays, synthetic Emulsion Polymerization of Poly(Methacrylic Acid) Nanoparticles: Effects of Different Cationic Surfactants NOOR ANIZA HARUN * , NUR SHAHIERA MD TAHIER, NUR NASYITA KAMARUDDIN, MAZIDAH MAMAT and SYARA KASSIM Advance Nano Materials Research Group, School of Fundamental Science, Universiti Malaysia Terengganu, 21030, Kuala Nerus, Terengganu, Malaysia *Corresponding author: Fax: +60 9 6683608; Tel: +60 9 6683317; E-mail: nooraniza@umt.edu.my Received: 22 May 2018; Accepted: 16 July 2018; Published online: 31 August 2018; AJC-19062 The synthesis of poly(methacrylic acid) (PMAA) nanoparticles were prepared via emulsion polymerization technique by using different types of cationic surfactants and potassium persulfate as water soluble initiator. The different ranges of cationic surfactants, namely, cetyltrimethylammonium bromide (CTAB), tetradecyl trimethylammonium bromide (TTAB) and cetylpyridinium chloride (CPC) were used at different concentration (below, equivalent and above CMC). FTIR was conducted to observe the absorption peaks at 1600-1500 cm –1 , 1800-1700 cm –1 , 2700-2500 cm –1 and 3300-3000 cm –1 , represents C=O stretching, C-O-C vibration, CH3 and O-H stretching, respectively. SEM was performed to determine the particle size and morphology of PMAA nanoparticles where it showed that the particle size of PMAA nanoparticles between 400-600 nm. The weight decomposition data was obtained from TGA where it showed that the PMAA nanoparticles synthesized using TTAB as cationic surfactant prepared at equivalent CMC is the most stable PMAA nanoparticles. Keywords: Hydrophilic polymer nanoparticles, Emulsion polymerization, Methacrylic acid, Biodegradable. Asian Journal of Chemistry; Vol. 30, No. 10 (2018), 2299-2304 This is an open access journal, and articles are distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) License, which allows others to copy and redistribute the material in any medium or format, remix, transform, and build upon the material, as long as appropriate credit is given and the new creations are licensed under the identical terms. hydrophilic polymer nanoparticles become attractive alter- natives for biomedical applications especially in the novel drug delivery system because of their solubility in water and low intrinsic toxicity of polymer nanoparticles. Moreover, it can also enhance the physical and chemical stability of drugs and can prevent the aggregation of the drugs [10]. Amongst nume- rous types of synthetic hydrophilic polymer nanoparticles, poly(methacrylic acid) (PMAA) is attracted high interest in biomedical applications due to its biodegradability and bio- compatibility. The carboxyl groups in PMAA provide binding sites for cationic anticancer drugs such as doxorubicin [11]. In the previous study, we have successfully synthesized PMAA nanoparticles via emulsion polymerization technique utilizing anionic type of surfactant at different concentrations [12]. Emulsion polymerization is one of the various polymeri- zation methods that can be employed to produce high mole- cular weight synthetic polymer nanoparticles with no or negli- gible volatile organic compounds. The main components involved in emulsion polymerization are monomer, surfactant and initiator which composed in aqueous medium in the pre- sence of heat, pressure or catalysis that can change the chemical