Tel Aviv University researchers have created a unique glass that is both an effective adhesive and extremely transparent. This arbitrary glass could significantly impact a number of high-tech industries. Researchers from Tel Aviv University (TAU) have created a new type of glass with unique and even contradictory properties, such as strong adhesive (adhesive) and incredibly transparent at the same time. The glass, which forms spontaneously when in contact with water at room temperature, could revolutionize many different fields, including optics and electro-optics, satellite communications, remote sensing, and biomedicine.

The glass was discovered by a group of researchers from Israel and around the world, led by graduate student Hal Finkelstein-Zuta and professor Ehud Gazit of the Shmunis School of Biomedicine and Cancer Research in the Faculty of Life Sciences and the Department of Materials Science and Engineering at TAU’s Faculty of Engineering. The results of the research were recently published in a respected scientific journal. Nature.

Process and properties of new glass

“In our laboratory, we work on biological convergence and use the wonderful properties of biology to produce innovative materials,” explains Professor Gazit. “Among other things, we study the sequences of amino acids, the building blocks of proteins. Amino acids and peptides have a natural tendency to bond with each other and form regular structures with a certain periodic arrangement, but during the study we discovered a unique peptide that behaved differently than anything we knew: it did not form any regular pattern, but an orderly, irregular, shapeless structure, which is what defines glass.”

At the molecular level, glass is a liquid substance whose molecular structure is irregular but whose mechanical properties are similar to those of a solid. Typically, glass is made by rapidly cooling molten materials and “freezing” them in this state before crystallizing, resulting in an amorphous state that provides unique optical, chemical, and mechanical properties, as well as durability, versatility, and longevity. Researchers at TAU ​​have discovered that an aromatic peptide consisting of a sequence of three tyrosines (YYY) spontaneously forms molecular glass upon evaporation of an aqueous solution at room temperature.

“Commercial glass, as we all know it, is made by rapidly cooling molten materials, a process called vitrification,” says Gal Finkelstein-Zuta. “The amorphous liquid-like organization needs to be stabilized before it can be arranged in a more energy-efficient way, as in crystals, and this requires energy; it must be heated to high temperatures and then cooled immediately. On the other hand, the glass we discovered, which is made of biological building blocks, forms spontaneously at room temperature without the need for energy such as high heat or pressure. Just like making a refrigerator, dissolve the powder in water and the glass will form. For example, we made lenses from our new glass. Instead of going through a long grinding and polishing process, we dropped the drop onto the surface and controlled its curvature and hence focus by simply adjusting the volume of the solution.”

The properties of TAU’s innovative glass are unique in the world and even contradictory: it is very hard, yet can self-heal at room temperature; it is a strong adhesive and at the same time transparent over a wide spectral range from visible light to mid-infrared.

Potential effects and uses

“For the first time, someone has managed to create molecular glass under simple conditions,” says Professor Gazit, “but the properties of the glass we have created are no less important. It is a very special glass. On the one hand, it is very strong, on the other hand, it is very transparent; much more transparent than ordinary glass. The ordinary silicate glass that we all know is transparent in the visible light range, while the molecular glass we have created is transparent deep into the infrared range. It has many applications in areas such as satellites, remote sensing, communications and optics. It is also a strong adhesive, it can bond different glasses and also repair cracks that form in it. This is a set of properties that no other glass in the world has, that has great potential in science and technology, and we have obtained all of this from a single peptide, a small piece of protein.”