Degradable PDA@PNIPAM-TA Nanocomposites for Temperature- and NIR light-Controlled Pesticide Release

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology
• Agricultural Science

Background:

• Conventional pesticide formulations face limitations in efficacy and environmental impact.
• Controlled pesticide delivery systems offer advantages in targeted release and reduced environmental exposure.
• Smart materials responsive to environmental stimuli are crucial for advanced delivery systems.

Purpose of the Study:

• To prepare degradable poly(N-isopropylacrylamide) (PNIPAM)-tannic acid (TA) microgels and PDA@PNIPAM-TA nanocomposites for smart pesticide delivery.
• To investigate the stimuli-responsive release behavior and foliar adhesion properties of the developed materials.
• To evaluate the efficacy of the nanocomposites for delivering imidacloprid (IMI) under varying environmental conditions.

Main Methods:

• Synthesis of PNIPAM-TA microgels and PDA@PNIPAM-TA nanocomposites using a high-gravity rotating packed bed reactor (RPB).
• Characterization of material properties, including temperature-dependent swelling/deswelling and pH-induced degradation.
• Dynamic contact angle tests for foliar adhesion assessment and encapsulation/release studies of imidacloprid (IMI).

Main Results:

• The microgels and nanocomposites exhibited reversible temperature-dependent swelling/deswelling and irreversible pH-induced degradation.
• Introduction of TA and PDA enhanced foliar adhesion and deposition efficiency.
• IMI release rate was significantly correlated with temperature (23.5% at 25°C vs. 81.2% at 40°C) and enhanced by near-infrared (NIR) light.

Conclusions:

• The developed PNIPAM-TA and PDA@PNIPAM-TA systems provide a facile method for controlling pesticide release based on environmental stimuli.
• The tunable thermoresponsive behavior and enhanced adhesion properties make these nanocomposites promising for smart pesticide delivery.
• This work demonstrates the potential of high-gravity technology for creating effective and sustainable crop protection solutions.