Is aerogel biodegradable? (3 applications of aerogel) 

This article will explain the biodegradability aspect of aerogel. Other covered topics would include:

  • Is aerogel biodegradable?
  • Can you recycle aerogel?
  • What are the uses and reuses of aerogel?
  • Are there any (more) green alternatives to aerogel?
  • What are safe disposal practices of aerogel?
  • FAQs

Is aerogel biodegradable?

The biodegradability aspect of aerogel greatly varies based on the materials used to make aerogel. If aerogel is made from silica or cellulose, it would be biodegradable. If aerogel is made from metal or plastic, it would not be biodegradable. 

As regards the recycling aspect, cellulose aerogels are feasible to be recycled whereas silica or metallic aerogels are preferred not to be recycled as it is a highly consumptive process. 

The versatility of aerogel is not just limited to the materials that make it but also expands to its applications. Aerogel may be used for thermal insinuation, waste management, and even nuclear particle detection. NASA also uses aerogel to keep rocket fuel at optimum temperatures. 

Is aerogel biodegradable? (3 applications) 

Aerogel is a broad term that is made of a group of materials and minerals. The materials that are used in this have the same geometric properties. Such as they are extremely porous, solid foam, and have high connectivity between branched structures. 

The versatility of aerogel is not just limited to the materials that make it but also expands to its applications. Aerogel may be used for

  • thermal insinuation
  • waste management,  
  • nuclear particle detection

Aerogel is often referred to as “frozen smoke”. It can be moulded in different shapes as it consists of 99% air and only a few percent solid. It is present in the form of foam. Aerogel is composed of carbon, iron oxide, organic polymers, gold, copper, and semiconductor nanoparticles. 

The most common type of aerogels is those made from silica. These are termed silica aerogel. However, there are certain reservations regarding the eco-friendly aspect of silica aerogel. 

Recently aerogel has started to be processed by using paper waste that uses cellulose it. Cellulose is the most abundant polymer that is available on earth naturally. In the early 1930s, aerogel made of cellulose was developed by taking out liquid from a paper by using a supercritical drying method. 

Aerogels have low density, high porosity, large specific surface area and efficient surface chemical activities. In this way, cellulose aerogel is a porous material. Normally, aerogels are made of silica which is not environmentally friendly nor recyclable, but the recent development of cellulose-based aerogels has become recyclable and biodegradable. 

Scientists have developed a novel method to convert paper waste into environmentally friendly products. Such cellulose-based aerogels are cost-effective, high absorption oil capacity. Cellulose aerogels have four times higher capacity than commercially available aerogels in terms of absorption properties. 

As regards the major question, the answer greatly varies on the type of material used to make aerogel. If aerogel is made from silica or cellulose, it would be biodegradable. If aerogel is made from metal or plastic, it would not be biodegradable. 

Biodegradability is defined as the breakdown of life. Bio means life. By life, microbes are indicated such as bacteria, fungi, algae et cetera. 

These microbes would only degrade the material that they find nutritional content in. That is the primary reason why certain materials are biodegradable while some products such as plastics are not. 

Can you recycle aerogel?

Cellulose aerogel can be recycled as proven by research in the lab. Scientists recycled cellulose aerogel by using acetone. The remaining solution was processed and used further for experimentation. Although the sorption capacity of cellulose aerogels decreased as compared to the ones prepared freshly and used at first. 

For instance, sorption percentage after recycling decreased to 12%as compared to 17% used as fresh produced aerogels. Recycled aerogels give average results. But recycling aerogels by using acetone is cost-effective and provides efficient development in the process. 

Not all types of aerogels are recyclable, for instance, aerogels prepared from plastic bottles (PET) and rubber cannot be recycled. The problem is not just about the possibility but also the feasibility. And even if they are recycled after high chemical processing, they would have lower sorption capacity. 

Such recycling of aerogel will require a huge amount of chemicals and energy. So, this recycling process is not cost-effective or energy efficient. As compared to cellulose aerogels, PET recycled, and rubber waste recycled aerogels will also have the lowest sorption properties. 

Some researchers have developed aerosols out of metal waste. Such development of aerogel requires plenty of chemicals and huge amounts of energy. The development and processing of metal waste into cellulose is not environmentally friendly as it releases by-products that are harmful to the environment. 

Production of aerogels from metal waste produces harmful gases such as ammonia and methane mainly during the aluminium product recycling process. 

What are the reuses of aerogel and is it safe?

As different aerogels are made up of different sources such as cellulose, metal waste and rubber. These celluloses have different recycle and reuse properties, some of them show a huge decrease in sorption value and some show a slight decrease in sorption value after recycling or when reused. 

During oil spills, an absorption technique is used to remove oil. Aerogels which have a green impact on the environment, have high absorption capacity and cost-effective novel approaches can only be used. For such properties, the most abundantly used type of aerogel is made up of cellulose. 

As crude oil is important in the industrial sector. Crude oil is transported in tanks, and during its transporting, spills might occur which require cleaning, the cleaning is done by using aerogels which are made from different types of waste materials. 

The reuse of aerogels is safe, but they do not show the same results as they did in the first application. The absorption capacity of aerogels decreases when they are used again. And their recycling requires chemical processing, which does not show environmentally friendly results. 

Out of all aerogel types, cellulose aerogel shows an environmentally friendly impact on the environment. The washing, cleaning, and recycling of cellulose aerogel do not release harmful byproducts into the environment. and this is also not an energy-intensive product. 

Aerogels are also used in the insulation of buildings, the reuse of aerogels for insulation is safe. They provide efficient results in insulation properties to keep the place at the required temperature. 

Are there any (more) green alternatives to aerogel?

Aerogels themselves are considered alternatives to many other products in terms of insulation. For instance, in building insulation, aerogels are considered the most promising ones as they are cost-effective and do not have harmful impacts on the environment. 

Aerogels have proven to be the most effective insulators in building for both domestic and commercial use. Aerogels are ultrathin materials which are processed from different material waste. Aerogels have also proved to be superior to synthetic-based insulations. 

Aerogels have efficient insulation and absorption properties, but when it comes to drawbacks, they fall into one which is production cost. But as compared to other products, aerogel has less environmental impact based on specific types of the source material.

Aerogel-based insulation has shown 20% more efficient improved insulation properties as compared to the conventional foamed insulation systems. Aerogel-based insulation is energy effective when it comes to energy consumption.

What are safe disposal practices for aerogel?

Silica-based aerogels are disposed of into the environment in landfills which damages the operational stages of landfill processes as it releases harmful products into the environment. researchers have found a green method of silica-based aerogels which is thermal degradation or recycling. 

Another method of safe disposal of aerogels is waste to energy combustion which requires incineration of municipal waste, but this approach is not applied to all aerogels, it is only aimed at steel and cement industries. 

Another methodology that has come to be observed by researchers is the depolymerization methodology, such a process requires end-of-life products to produce new forms of polymers. Such processing requires reagents under specific reaction time, but it requires high temperature and intensive use of energy. 

Ultimately, aerogels are discarded into the landfills, where they emit toxic chemicals and malfunction the operation of landfills, such disposal is not only harmful to the environment but also to the system and processes that it is disposed of into. 

As mentioned above, some methods are safe to approach but they require an intensive amount of chemicals and huge energy consumption depending on the type of aerogel. But most aerogels reuse recycling uses. 

Safe disposal of aerogel is essential as they emit harmful gases and byproducts when disposed of into the environment mainly in landfills. 

Conclusion

It is concluded that the biodegradability aspect of aerogel greatly varies based on the materials used to make aerogel. 

Biodegradability is defined as the breakdown by life. Bio means life. By life, microbes are indicated such as bacteria, fungi, algae et cetera. 

These microbes would only degrade the material that they find nutritional content in. That is the primary reason why certain materials are biodegradable while some products such as plastics are not. 

If aerogel is made from silica or cellulose, it would be biodegradable. If aerogel is made from metal or plastic, it would not be biodegradable. 

As regards the recycling aspect, cellulose aerogels are feasible to be recycled whereas silica or metallic aerogels are preferred not to be recycled as it is a highly consumptive process. 

The versatility of aerogel is not just limited to the materials that make it but also expands to its applications. Aerogel may be used for thermal insinuation, waste management, and even nuclear particle detection. NASA also uses aerogel to keep rocket fuel at optimum temperatures. 

Frequently Asked Questions: Is aerogel biodegradable?

What is the most common type of aerogel?

The most common type of aerogels is those made from silica. These are termed silica aerogel. However, there are certain reservations regarding the eco-friendly aspect of silica aerogel. 

What are the applications of aerogel?

Aerogel may be used for thermal insinuation, waste management, and even nuclear particle detection. NASA also uses aerogel to keep rocket fuel at optimum temperatures. 

References

  • Hrubesh, L. W. (1998). Aerogel applications. Journal of Non-Crystalline Solids, 225, 335-342.
  • Gurav, J. L., Jung, I. K., Park, H. H., Kang, E. S., & Nadargi, D. Y. (2010). Silica aerogel: synthesis and applications. Journal of Nanomaterials, 2010.
  • Carraher, C. E. (2005). General topics: silica aerogels—properties and uses. Polymer News, 30(12), 386-388.
  • Carlson, G., Lewis, D., McKinley, K., Richardson, J., & Tillotson, T. (1995). Aerogel commercialization: technology, markets and costs. Journal of non-crystalline solids, 186, 372-379.
  • Jones, S. M. (2006). Aerogel: space exploration applications. Journal of sol-gel science and technology, 40(2), 351-357.
  • Chen, H. B., Chiou, B. S., Wang, Y. Z., & Schiraldi, D. A. (2013). Biodegradable pectin/clay aerogels. ACS applied materials & interfaces, 5(5), 1715-1721.

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