Control of colloidal CaCO3 suspension by using biodegradable polymers during fabrication
Nemany A. N. Hanafy1,2, Maria Luisa De Giorgi2, Concetta Nobile1 , Mariafrancesca Cascione2 , Ross Rinaldi2 and Stefano Leporatti1
(1) CNR NANOTEC- Istituto di Nanotecnologia, Via Monteroni Lecce (Italy). (2) Department of Mathematics and Physics "E. De Giorgi" University of Salento, Via Monteroni, Lecce (Italy)
Abstract
Fabrication of homogenous CaCO3 particles is a significant step in assembling polyelectrolyte capsules. It is crucial to control the dimensions, the shape and the charge of the calcium carbonate particles in order to have homogenously separated and charged templates as a final result. Recently, crystallization of CaCO3 was done by adding Poly (Sodium 4-Styrenesulfonate) (PSS) as negatively charged polymer and Poly (Allylamine Hydrochloride) (PAH) as positively charged polymer and the results were surprising. The homogenous particles were separated and they carried the same charge of the used polymer. The aim of this work was to investigate the synthesis process of CaCO3 particles in different experimental conditions: calcium carbonate was produced in presence and in absence of water and with addition of appropriate polymers. In particular, Chitosan (CHI) and Poly acrylic acid (PAA) were chosen as biodegradable polymers whereas PSS and PAH were chosen as non-biodegradable polymers. Shape and diameter of particles were investigated by using transmission and scanning electron microscopy, elemental composition was inferred by energy dispersive X-ray analyses whereas their charges were explored by using zeta potential. In a successive work, it was also found that Poly allylamine hydrochloride (PAH) was able to control CaCO3 during fabrication towards elongated shape forming rods- like CaCO3. This might be related to PAH band answers to ionic stress of alkaline Na2CO3. Chitosan as promising polymer for medical application conjugated with polygalacturonic acid forming (CHI-PgA) complex is used to coat CaCO3. Hence, this complex is entrapped inside PAH-CaCO3 pores. This CHI-PgA complex is formed through electrostatic interaction between amino groups of PAH forming layer-network connection after dissolution of CaCO3
References
1) Nemany Hanafi, Concetta Nobile, Maria Luisa De Giorgi , Ross Rinaldi and Stefano Leporatti “Control of Colloidal CaCO3 suspension by using biodegradable polymers during fabrication” Beni-Suef University Journal of Basic and Applied Sciences. 4 (2015) pag. 60-70; http://dx.doi.org/10.1016/ j.bjbas.2015.02.009.
2) Nemany Hanafi, Maria Luisa De Giorgi, Concetta Nobile, Mariafrancesca Cascione, Ross Rinaldi and Stefano Leporatti ”CaCO3 rods as chitosan-polygalacturonic acid carriers for bromopyruvic acid delivery ” Science of Advanced Materials (SAM) 2015, in press.