In the quest for sustainable materials, cork has long been a champion, but its susceptibility to wear has limited its applications. Now, a groundbreaking study led by Dr. B. Tiss from the Physics Center of Minho and Porto Universities (CF-UM-UP) is set to revolutionize the way we think about this eco-friendly material. The research, published in the journal Applied Surface Science Advances (translated from English), focuses on enhancing cork’s durability through innovative coatings, paving the way for new possibilities in various industries, including energy.
Cork, a versatile material derived from the bark of the cork oak tree, has been used for centuries in wine stoppers and more recently in products ranging from bags to aerospace components. However, its tendency to wear down under friction and mechanical stress has been a significant drawback. Dr. Tiss and his team at the Laboratory for Materials and Emergent Technologies (LAPMET) have tackled this challenge head-on, exploring the potential of titanium dioxide (TiO2) and zinc oxide (ZnO) coatings deposited via magnetron sputtering.
The process involves depositing thin, optically transparent films of TiO2 and ZnO onto cork substrates. While TiO2 films exhibited an amorphous structure, ZnO films displayed a distinct texture, aligning along the (002) direction of the hexagonal wurtzite structure of zinc oxide. This structural difference proved crucial in their performance.
“ZnO-coated cork showed a markedly lower coefficient of friction against stainless steel balls compared to uncoated cork,” Dr. Tiss explained. “This reduction in friction, coupled with improved wear resistance, makes ZnO-coated cork a promising candidate for applications where durability is key.”
The wear rate of the samples was evaluated using a novel method based on energy dispersive spectra analysis. All coated samples demonstrated enhanced wear resistance, with ZnO films showing the most significant improvement. The detection of metallic oxide coatings within the wear track after tribological tests indicated strong adhesion to the cork substrate, further supported by tensile tests.
So, what does this mean for the energy sector? Cork’s lightweight, insulating properties, and sustainability make it an attractive material for various applications, from building insulation to components in renewable energy systems. By enhancing its durability, this research opens the door to more robust, long-lasting, and eco-friendly solutions. Imagine cork-based components in wind turbines or solar panels, designed to withstand harsh environmental conditions without compromising performance.
The implications of this research are far-reaching. As Dr. Tiss puts it, “This study is just the beginning. We’re excited about the potential of these coatings and the possibilities they open up for cork and other natural materials.”
The study, published in Applied Surface Science Advances, marks the first part of a comprehensive investigation. The team plans to extend their research to rubber, another versatile natural material, in a subsequent paper. As we continue to seek sustainable solutions, this research offers a glimpse into a future where eco-friendly materials are not just viable but superior. The energy sector, in particular, stands to benefit from these advancements, driving us closer to a greener, more sustainable future.
