Thermoresponsive ZIF-8@PNIPAm-co-MAA microgel composites with enhanced performance as adsorption/release platform
Juan A. Allegretto,a,b Juan M. Giussi,a Sergio E. Moya,c Omar Azzaroni,a* and Matias Rafti
a. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CONICET, Calle 64 y Diag.
113, 1900 La Plata, Argentina.
b.Universidad Nacional de San Martin (UNSAM), San Martín, Argentina.
c.CIC biomaGUNE, Paseo de Miramón 182, Donostia-San Sebastián, 20014, España.
Abstract: We hereby present a strategy to develop a composite material that shows a combination of the intrinsic properties of its components, by using poly(N-isopropyl-acrylamide)-derived thermo-responsive microgels and Zn-based Metal-Organic Framework (MOF) ZIF-8, capable of selective adsorption. For the construction of the composite, methacrylic acid was included as co-monomer in the microgel, in order to position carboxylic acid moieties within the polymeric matrix, which via preconcentration of Zn ions would trigger ZIF-8’s confined heterogeneous nucleation. The highly integrated composite obtained features thermoresponsivity and permanent porosity. Methylene blue adsorption/desorption experiments were performed, revealing a dramatic enhancement of its cargo capacity together with an also increased release efficiency.