A research team from the National University of Singapore’s (NUS) Faculty of Engineering has achieved a world’s first by successfully converting paper waste into green cellulose aerogels that a re non-toxic, ultralight, flexible, extremely strong and water repellent.
By this method there will be a reduction of environmental problems. Paper related waste generated annually causes destruction of forestation and pollution. Recycling of converting paper waste into useful products, therefore contributes towards environmental conservation.
The NUS team uses a more eco-friendly process to convert paper waste into aerogels. “Our fabrication process uses 70 percent less energy, produces fewer polluting emission into the air and water, as well as uses less dioxins in the chlorine bleaching process. It is also faster- the entire process only takes three days,” explains Assistant Professor Duong Hain Minh, team leader from the department of Mechanical Engineering.
This material is ideal for applications such as oil spill cleaning, heat insulation as well a packaging, and it can also be used for coating materials for drug delivery and for various biomedical applications. “Aerogels, which are among the lightest solid materials known to man, are one of the finest insulation materials available. Traditional aerogels are mainly made of silica, which is not environmentally-friendly,” said Asst. Prof. Duong.
The cellulose aerogels has a super high oil absorption capacity. Coated with Trimethoxy-methylsilane (MTMS), the aerogels are water repellent and are capable of absorbing oil up to 90 times their dry weight, making them up to four times more effective than commercial oil absorbants.
Another application of the aerogels is to serve as insulation materials for buildings. Their water repellent property allows them to be adaptable to both dry and rainy weather and their structure remains stable for about six months in tropical climate. Plastic-based packing materials such as bubble wrap could be replaced with biodegradable aerogel-based foam or advanced cellulose aerogel nano sheets, which are environmentally friendly. Compressed cellulose aerogels can also be used to plug life-threatening wounds such as a gunshot or stabbing lesion by injecting them into the would cavity. The sponges expand inside the cavity, creating pressure that can block bleeding and life-threatening hemorrhage in 20 seconds or less.
The team has filed a patent for their invention in USA, China, India and Southeast Asia The technology has been licensed by the NUS Industry Liaison Office, which is part of NUS Enterprise, to Bronxculture Pte Ltd in November 2015 for commercialization. They intend to manufacture the aerogel and further expand its applications.