1. Controlled drug delivery in patients
2. Mobile air-conditioning systems
3. Preparation of industrial lubricants
Select the correct answer using the code given below:
Explanation
Hydrogels are three-dimensional polymer networks that can absorb and retain large amounts of water while preserving their structure. With their biocompatibility, flexibility, and customizable properties, they are widely utilized across various applications.
Option 1 is correct: Hydrogels have a porous, water-attracting structure that allows them to expand and contract in response to stimuli. This makes them ideal for controlled drug delivery, ensuring precise and sustained release in liquid environments.
Option 2 is incorrect: Hydrogels are not commonly used in mobile air-conditioning systems. Air-conditioning relies on compressors, refrigerants, and heat exchangers, and though materials with moisture retention might play a minor auxiliary role (like evaporative cooling pads), hydrogels are not a standard component in these systems.
Option 3 is incorrect: Hydrogels do not serve as specific base materials or additives in conventional industrial lubricants. Industrial lubricants typically rely on oils, greases, and synthetic compounds designed for reducing friction and wear. Hydrogels are not chemically or mechanically suited for this purpose. Note: UPSC has given Option(a) as an official answer.