Cellulose films to be used as insulators for houses and automobiles
What do you do when you feel extremely hot during summers? You turn on the AC! Well, while ACs do the job brilliantly and help us cool down, they come with certain cons, such as emission of heat and other toxic greenhouse gases (such as GHG and CFCs), not to forget they consume high amounts of energy to run efficiently.
As a result, it had become imperative for the scientists to come up with a sustainable and environmental-friendly alternative. Guess what? Finally, they have done it. Turns out, they have developed a plant-based cellulose film that has an unusual characteristic. It gets cooler when exposed to sunlight. Not only that, they come in a series of textures and colours, which are bright and iridescent. Experts believe that this cutting-edge innovation could one day replace ACs in houses, offices, schools, colleges and even automobiles and can function without any external power source. How cool is that!
These brand-new findings will be officially presented by a team of Cambridge University in the upcoming summit that will be held at American Chemical Society (ACS). Deemed as ACS Spring 2023, it is a hybrid meet that happens every year from 26th to 30th March and presents more than 10000 projects on different scientific topics and researches.
Coming back to the latest innovation, it was inspired from Passive Daytime Radiative Cooling (PDRC). It refers to the technique in which a surface emits its own heat into space without it being absorbed by the air or the atmosphere. Intriguing, right? Guess what the result is? The environment around becomes significantly colder that the actual temperature. But to make PDRC possible in real life takes a lot of energy. As a result, this cellulose film which occurs naturally has caught the attention of scientists. It too makes its surrounding cooler than usual, reflects solar light but do not absorb it. Do you realise what this means? Yes, it can be used on buildings and other structures free of cost and do away with the mechanism of ACs and other power-intensive cooling systems altogether.
What’s interesting here is that, PDRC have been available for a few years in the form of paints and films. But most of them are artificially white or have mirrored finish, thus lowering its cooling level. Coloured paints and films are also out of question as they have reverse and undesirable warming effects.
This is where cellulose comes into play. It is naturally pigmented and has a high rate of PDRC. The researchers involved in the study has deemed this ability as structural colouring and are currently looking for more other options. For now, cellulose nanocrystals (CNCs) made directly out of cellulose will do the job. Not only will it cool the surroundings, but also give it a natural colour. Cool, right?
The researchers have also found out that the CNCs can be used for other purposes as well, such as detection of environmental contaminants and weather forecasts. In addition to CNCs, ethyl cellulose has also been found to produce an effective and colouful bi-layered PDRC film with a capacity to be 40 degrees cooler.