In which of the following are hydrogels used?

Select the correct answer using the code given below:

(a) 1 only
(b) 1 and 2 only
(c) 2 and 3 only
(d) 1, 2 and 3

Correct Answer: (d) 1, 2 and 3

Explanation:

Controlled drug delivery in patients:
- Hydrogels are extensively used in controlled drug delivery systems due to their tunable properties, controllable degradation, and ability to protect labile drugs. They provide spatiotemporal control over drug release and are highly biocompatible, making them suitable for delivering a wide range of therapeutic agents, including small molecules, proteins, and nucleic acids .
Mobile air-conditioning systems:
- Hydrogels have been proposed and investigated for use in passive thermal management systems. They can absorb moisture from the air and provide cooling through evaporative processes, similar to how human skin cools through sweating. This property makes them suitable for applications in cooling electronics and potentially in mobile air-conditioning systems.
Preparation of industrial lubricants:
- Hydrogels are also used in the preparation of industrial lubricants. They can be fabricated with various organic and inorganic gelators to provide lubrication, reduce friction, and wear in mechanical systems. This makes them valuable in industrial applications where efficient lubrication is critical .

Hydrogels are three-dimensional polymer networks capable of holding large amounts of water due to their hydrophilic structure. They can be synthesized from natural, synthetic, or semi-synthetic polymers and can be cross-linked physically or chemically.
Controlled drug delivery:
- Hydrogels offer spatial and temporal control over drug release, protecting drugs from degradation and allowing for precise delivery to target sites.
- They are used in various medical applications, including cancer treatment, wound healing, and tissue engineering.
Thermal management:
- Hydrogels can absorb and release moisture, providing a passive cooling mechanism. This property is utilized in cooling high-power electronics and potentially in air-conditioning systems to reduce energy consumption .
Industrial lubricants:
- Hydrogels reduce friction and wear in mechanical systems, making them suitable for use in industrial lubricants. They can be tailored to provide specific lubrication properties, enhancing the efficiency and lifespan of mechanical components .