The Road to Sustainability is Paved With Good Inventions
Saving the planet and the environment is a serious challenge, and scientists all over the world are working hard to find ways to tackle the various issues of pollution, over-consumption, and preserving natural resources from all angles. Materials science contributes new discoveries on a daily basis, and sometimes, sustainability in materials science is approached from an unusual direction.
Wood-based foam could help offset air-conditioning costs
Using air-conditioning devices to keep buildings cool is expensive, wasteful, and overall bad for the environment. Researchers at the American Chemical Society have developed a material that reflects sunlight, emits absorbed heat, and acts like a thermal insulator that could be used to keep buildings cool.
The novel material is made from wood-based cellulose nanocrystals and has the form of lightweight foam. The results of the study show that by using it to coat the building, cooling energy needs could be reduced by 35.4 percent on average.
Coating the building with the novel wood foam could offset the high energy consumption of air-conditioning devices.
The wood-based foam has special properties that are superior to those of other materials built for this purpose, and it presents none of their disadvantages. Unlike similar materials, the new coating admits little heat to the buildings when the weather outside is hot, and it works well even in humid, hot, or cloudy weather. Reflecting 96 percent of visible light and emitting 92 percent of absorbed infrared radiation, the new materials proved to be robust and very efficient in preventing heat from passing through.
The foam is produced by connecting cellulose nanocrystals together with a silane bridge and then freeze-drying them under a vacuum. During the process, the nanocrystals are vertically aligned, resulting in white, lightweight foam.
While conducting the tests, researchers noticed that by compressing the foam, they were able to modify its properties so the cooling parameters of the foam could be adapted to various purposes and a wide range of environments, allowing this innovation to contribute even more to the common goal of sustainability.
Pollen-based paper can be erased and reprinted
Although the world is moving toward pervasive digitalization of communications, paper still has an important place in our economies. The conventional process of making paper, which involves cutting down and pulping trees, accounts for 33 to 40 percent of all industrial wood used in the global economy, so finding alternative ways to make paper could have a huge impact in terms of stopping deforestation and mitigating carbon emissions. A novel pollen-based paper developed by scientists at Singapore’s Nanyang Technological University (NTU) could offer a solution to this issue. Their paper is not only produced in a more environmentally-friendly way, but also allows images to be printed and then erased, with the paper being reused to print on again multiple times.
The team of researchers printed colored images on the pollen paper with a laser printer, then removed the toner with an alkaline solution without damaging the paper. After drying, the paper could be reused for printing. This process can be repeated up to eight times before the surface of the paper shows signs of loss of structural integrity and the quality of printed colors declines.
The conventional recycling process of laser-printed paper involves many steps that cost time, energy, and human resources and are a source of carbon emissions as well. The pollen paper could significantly reduce these costs and negative effects by shortening the process and skipping steps like re-pulping or reconstruction. Also, the process of producing paper from pollen is simpler than the conventional method and consumes significantly less energy.
Nature produces pollen in large amounts, so it is a raw material that is not only easy and efficient to produce, but also cheap and sustainable.
“Through this study, we showed that we could print high-resolution color images on paper produced from a natural, plant-based material that was rendered non-allergenic through a process we recently developed. We further demonstrated the feasibility of doing so repeatedly without destroying the paper, making this material a viable eco-friendly alternative to conventional wood-based paper. This is a new approach to paper recycling – not just by making paper in a more sustainable way, but also by extending the lifespan of the paper so that we get the maximum value out of each piece of paper we produce,” said Prof. Subra Suresh, NTU President and lead author of the paper.
The pollen-based paper is hypoallergenic, easily recyclable, and can be made from a highly renewable source. Nature produces pollen in large amounts, so it represents a raw material that has all the benefits of scalability, economic efficiency, and sustainability. “By integrating conductive materials with the pollen paper, we could potentially use the material in soft electronics, green sensors, and generators to achieve advanced functions and properties,” said Prof. Cho Nam-Joon, another lead author of the paper.
Your clothes could be dyed with microbes to keep the rivers safe
The dyes that are currently used to color our clothes play a huge part in the textile industry’s overall image as a polluting and unsustainable sector. Artificial colors leaking during production or even in the washing process are degrading the planet’s water resources by inhibiting plant growth and increasing the toxicity, mutagenicity, and carcinogenicity of the water consumed both by animals and humans. As an indirect contribution to pollution, the wastewater treatment that is necessary for removing the textile chemicals from the water is energy-intensive and carbon-emitting.
A better and healthier alternative is to use natural dyes extracted from plants. However, that is not a sustainable option, either. Now, scientists have proposed a completely different solution – obtaining dyes from microbes.
Companies like Colorifix, Pili, and Textile Lab are studying how to engineer such microbes and brew them in vats, in a process similar to beer production, then use them to naturally deposit dyes directly onto fabrics. Colorifix claims that its microbial dyes use at least 49 percent less water and 35 percent less electricity than modern cotton dyeing processes, potentially reducing carbon emissions by 31 percent. The situation is even more promising when it comes to synthetic materials like polyester or nylon.
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