A hot pack is a small heating device that uses chemical reactions to release heat. It is widely used for winter heating and keeping warm in cold environments. Its principle is usually based on the chemical reaction of iron powder oxidation and heat release. In recent years, with the improvement of the performance of hot pack products and the increase in environmental protection needs, activated carbon has been widely used in hot pack as a key material. This article will explore the specific application of activated carbon in hot pack, including its working

I.principle, performance advantages and its potential for future development

1.The basic principle of hot pack

The heating principle of hot pack is based on chemical reaction-iron powder reacts with oxygen in the air to generate iron oxide and release heat at the same time. The main ingredients include iron powder, salt, water and other auxiliary materials, while activated carbon, as a special additive material, plays an important role in improving the performance of hot pack.

Iron powder oxidation reaction

Iron powder reacts with oxygen in the air under certain humidity and catalyst, and the chemical equation is as follows:

4Fe+3O2+6H2O→4Fe(OH)3​+heat

II.The specific role of activated carbon in the hot pack

1. Regulate air circulation and promote reaction

Activated carbon is a material with a highly porous structure and a large specific surface area. This property enables activated carbon to adsorb and store oxygen in the air, ensuring a more stable supply of oxygen required for the oxidation reaction of iron powder. By regulating air circulation, activated carbon can control the reaction rate, making the heating time of the hot pack more durable and uniform.

2. Moisture absorption and moisture maintenance to maintain reaction conditions

The oxidation reaction of iron powder requires the participation of water, and the volatilization of water may cause the reaction to be interrupted. The porous structure and hydrophilicity of activated carbon enable it to absorb moisture in the environment while avoiding the rapid loss of moisture, thereby providing a stable humidity environment for the oxidation reaction of iron powder.

3. Adsorb by-products and keep the product clean

During the oxidation process of iron powder, certain by-products (such as rust, a small amount of odor, etc.) will be produced. Activated carbon has a very strong adsorption capacity, which can effectively adsorb these by-products, reduce the generation of odor, and improve the comfort of using the hot pack.

4. Prolong the heating time and improve product performance

Activated carbon can prolong the heating time of the hot pack by regulating the reaction rate and the short-term release of adsorbed heat. For example, some warm babies claim to be able to heat for 10 hours or even longer, thanks to the dynamic balance of activated carbon on oxygen and water supply.

III.Performance advantages of activated carbon in the application of warm babies

1. High efficiency

Activated carbon, with its huge specific surface area and high efficiency adsorption capacity, provides strong technical support for the performance optimization of warm babies. The use of this material greatly improves the heating efficiency and service life of warm babies.

2. Environmental protection

Compared with some chemical additives (such as silica gel powder) that may be added to traditional hot pack materials, activated carbon has a wide range of sources, low processing energy consumption, is non-toxic and harmless, and is environmentally friendly.

3. Safety

Activated carbon has high stability, will not release harmful substances during the use of hot pack, and is non-irritating to human skin, ensuring the safety of the product.

IV.Application of activated carbon modification in hot pack

In order to further improve the performance of activated carbon, researchers have modified activated carbon. For example, the use of oxidation modification, nitrogen doping and other technologies can significantly enhance the adsorption capacity and thermal conductivity of activated carbon. In the application of hot pack, modified activated carbon can better regulate the heat release rate and improve the overall performance of the product.

Increasing the functional groups (such as carboxyl and hydroxyl) on the surface of activated carbon through oxidation treatment can improve its hydrophilicity and ability to adsorb moisture, which is suitable for hot pack products in low humidity environments.

The introduction of nitrogen-containing groups can improve the polar adsorption capacity of activated carbon, making it more suitable for a variety of chemical reaction conditions, thereby more efficiently controlling the reaction rate.

V.Potential of activated carbon in the future development of hot pack

With the development of intelligent material technology, activated carbon may be combined with intelligent temperature control materials to realize the automatic temperature control function of hot pack in different environments.

Nano-grade activated carbon, with its larger specific surface area and higher adsorption performance, may be widely used in high-end hot pack products in the future, providing longer and more stable heating effect.

At present, most hot pack products are disposable, but the renewability of activated carbon makes it have the potential for recycling. By developing activated carbon regeneration technology, the negative impact of hot pack on the environment can be reduced, which is in line with the concept of green development.

As a multifunctional material, activated carbon plays an important role in regulating air circulation, absorbing moisture, adsorbing by-products and prolonging heating time in hot pack. Its high efficiency, safety and environmental protection not only improve the performance of hot pack, but also provide more possibilities for the future development of products. Through the combination of modification technology and intelligent materials, activated carbon is expected to be more widely used in hot pack and related warming products, bringing more comfort and convenience to mankind.

In the future, with the continuous advancement of science and technology, the performance of activated carbon will be further optimized, and its application prospects in hot pack and other fields will be broader.