When Interfaces Decide: Stimulus-Driven Corona-Controlled Transport in Mesoporous Silica Nanocarriers

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Engineering

Background:

• Mesoporous carriers typically exhibit passive diffusion, limiting controlled release.
• Polymer-coated systems offer dynamic interfacial permeability regulation.
• Stimulus-responsive materials are crucial for adaptive delivery systems.

Purpose of the Study:

• To develop a stimulus-responsive, corona-regulated urea carrier using waste-derived mesoporous silica nanoparticles.
• To investigate the impact of a dual thermo- and pH-responsive polymer corona on urea loading and release kinetics.
• To establish an interface-centered framework for corona-controlled transport in nanocarriers.

Main Methods:

• Functionalization of rice-husk-derived mesoporous silica nanoparticles (MSN) with chitosan-graft-poly(N-isopropylacrylamide) (CP) corona.
• Quantification of urea loading and release over 14 days under varying pH (5.5-8.5) and temperature (10-40 °C) conditions.
• Analysis of release profiles using Weibull modeling and interfacial/colloidal measurements (DLS, zeta potential, tensiometry).

Main Results:

• The developed MSN@CP nanocarriers achieved high urea loading (67.4%) and suppressed burst release.
• Urea release exhibited significant stimulus dependence, with higher release at 40 °C (81-89%) and pH 5.5, and lower release at 10 °C (39-44%).
• Corona restructuring under varying temperature and pH was confirmed, correlating with observed transport regimes.

Conclusions:

• The study demonstrates a waste-derived platform for adaptive urea release, controlled by a polymer corona.
• An interface-centered framework for corona-controlled transport in mesoporous nanocarriers was established.
• The developed nanocarriers offer potential for efficient and environmentally responsive fertilizer delivery.