Marjan Ashrafizadeh1, Kam Chiu Tam2, Aliyar Javadi3, Mahdi Abdollahi4, Saeid Sadeghnejad5, Alireza Bahramian6. 1. Department of Chemical Engineering, College of Engineering, University of Tehran, 11155/4563 Tehran, Iran. Electronic address: m.ashrafizadeh@ut.ac.ir. 2. Department of Chemical Engineering, Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada. Electronic address: mkctam@uwaterloo.ca. 3. Department of Chemical Engineering, College of Engineering, University of Tehran, 11155/4563 Tehran, Iran; Max Planck Institute of Colloids and Interfaces Potsdam/Golm, Germany. Electronic address: javadi.aliyar@ut.ac.ir. 4. Department of Polymer Reaction Engineering, Faculty of Chemical Engineering, Tarbiat Modares University, 14115-114 Tehran, Iran. Electronic address: abdollahim@modares.ac.ir. 5. Department of Petroleum Engineering, Faculty of Chemical Engineering, Tarbiat Modares University, 14115-114 Tehran, Iran. Electronic address: sadeghnejad@modares.ac.ir. 6. Department of Chemical Engineering, College of Engineering, University of Tehran, 11155/4563 Tehran, Iran. Electronic address: abahram@ut.ac.ir.
Abstract
HYPOTHESIS: A cross-linked amphiphilic nanogel containing a high mole% of hydrophilic pH-responsive moiety can provide enhanced functionality regarding stimuli-responsiveness, water-dispersibility, hydrophobic substance loading, and structural stability under harsh environmental conditions. These nanogels could be synthesized using a one-pot procedure for large-scale applications. Moreover, the interplay of various interaction forces in these colloidal systems is being investigated. EXPERIMENTS: Model nanogels consisting of acrylic acid-butyl acrylate-ethylene glycoldimethacrylate were synthesized using an emulsion copolymerization via a seeded semi-batch process under an acidic condition. The structures were assessed by Fourier transform infrared spectroscopy and potentiometric-conductometric titrations. Zeta potential, field-emission scanning electron microscopy, and transmission electron microscopy were used to evaluate the dispersion stability, size distribution, and structural distribution, respectively. Their stimuli-responsive behavior was studied by combining static and dynamic light scattering and titration analyses. FINDINGS: Monodisperse nanospheres of approximately 150 nm were successfully prepared by implementing a one-pot practical pathway. These nanogels displayed a dual thermo- and pH-responsive behavior, reflecting the high efficiency of physical cross-linking make it ideal for drug delivery and oil industry applications. Moreover, a novel symmetric pH-activated morphology transformation behavior was revealed. Accordingly, a compositional distribution was proposed and assessed by exploring the polymerization process.
HYPOTHESIS: A cross-linked amphiphilic nanogel containing a high mole% of hydrophilic pH-responsive moiety can provide enhanced functionality regarding stimuli-responsiveness, water-dispersibility, hydrophobic substance loading, and structural stability under harsh environmental conditions. These nanogels could be synthesized using a one-pot procedure for large-scale applications. Moreover, the interplay of various interaction forces in these colloidal systems is being investigated. EXPERIMENTS: Model nanogels consisting of acrylic acid-butyl acrylate-ethylene glycoldimethacrylate were synthesized using an emulsion copolymerization via a seeded semi-batch process under an acidic condition. The structures were assessed by Fourier transform infrared spectroscopy and potentiometric-conductometric titrations. Zeta potential, field-emission scanning electron microscopy, and transmission electron microscopy were used to evaluate the dispersion stability, size distribution, and structural distribution, respectively. Their stimuli-responsive behavior was studied by combining static and dynamic light scattering and titration analyses. FINDINGS: Monodisperse nanospheres of approximately 150 nm were successfully prepared by implementing a one-pot practical pathway. These nanogels displayed a dual thermo- and pH-responsive behavior, reflecting the high efficiency of physical cross-linking make it ideal for drug delivery and oil industry applications. Moreover, a novel symmetric pH-activated morphology transformation behavior was revealed. Accordingly, a compositional distribution was proposed and assessed by exploring the polymerization process.