New supramolecular plastic heals itself in an instant and it is highly biodegradable

Human ingenuity will take care of the plastics issue! If you suffer from plastophobia, please seek help immediately!

There is no need for any Western governments nor the European Union to prohibit plastics or microplastics! 

"Scientists experimenting with next-generation plastics at Finland's University of Turku have developed a form of the material with some impressive capabilities, most notably an ability to quickly break down after use. The eco-friendly "supramolecular" plastic is therefore highly recyclable and, with careful tuning of its water content, can be turned into an adhesive or even instantly self-heal when damaged. ..."

From the abstract:

"Plastics are one of the most widely used polymeric materials. However, they are often undegradable and non-recyclable due to the very stable covalent bonds of macromolecules, causing environmental pollution and health problems. Here, we report that liquid-liquid phase separation (LLPS) could drive the formation of robust, stable, and sustainable plastics using small molecules. The LLPS process could sequester and concentrate solutes, strengthen the non-covalent association between molecules and produce a bulk material whose property was highly related to the encapsulated water amounts. It was a robust plastic with a remarkable Young’s modulus of 139.5 MPa when the water content was low while became adhesive and could instantly self-heal with more absorbed water. Finally, responsiveness enabled the material highly recyclable. This work allowed us to understand the LLPS at the molecular level and demonstrated that LLPS is a promising approach to exploring eco-friendly supramolecular plastics that are potential substitutes for conventional polymers."

New supramolecular plastic heals itself in an instant

Researchers create new, unparallelled supramolecular plastic which is degradable and highly recyclable A research group headed by senior researcher Jianwei Li at the MediCity Research Laboratory has explored a new type of materials called supramolecular plastics that would substitute the conventional polymeric plastics with an eco-friendlier material promoting sustainable development. The mechanical properties of the supramolecular plastic created by the researchers using liquid-liquid phase separation were comparable to conventional polymers, but the new plastic decomposes much more easily and would be easier to reuse.

Small Molecule-based Supramolecular Plastics Mediated by Liquid-Liquid Phase Separation (open access)

Chemists find a contrary effect: how diluting with water makes a solution firm

Amazing stuff!

"... What is extraordinary, however, is that if the solution is diluted even further, a gel is formed again. Other supramolecular structures now form and it becomes a hydrogel again. And if it is then diluted even further, it becomes a liquid again. The paper carefully examined what the correct proportions of the active substances should be and at which concentrations the phase transitions take place. These transitions are also fully reversible. If concentrations are increased, the transitions from liquid to gel to liquid to gel occur at the same points. ...
but it is certain that it will have a major impact on chemistry and biology. ..."

From the abstract:

"Fascinating properties are displayed by synthetic multicomponent supramolecular systems that comprise a manifold of competitive interactions, thereby mimicking natural processes. We present the integration of two reentrant phase transitions based on an unexpected dilution-induced assembly process using supramolecular polymers and surfactants. The co-assembly of the water-soluble benzene-1,3,5-tricarboxamide (BTA-EG4) and a surfactant at a specific ratio yielded small-sized aggregates. These interactions were modeled using the competition between self-sorting and co-assembly of both components. The small-sized aggregates were transformed into supramolecular polymer networks by a twofold dilution in water without changing their ratio. Kinetic experiments show the in situ growth of micrometer-long fibers in the dilution process. We were able to create systems that undergo fully reversible hydrogel-solution-hydrogel-solution transitions upon dilution by introducing another orthogonal interaction."

Chemists find a contrary effect: how diluting with water makes a solution firm Today, in Science Magazine, TU/e researchers have published their research on new phase transitions of solutions and gels in water, which instinctively go against the basic principles of chemistry – and which they discovered by accident. In chemistry, everyone learns that you can go from a hydrogel to a liquid by diluting the hydrogel with water. For the reverse transition, you increase the concentration. However, TU/e researchers led by Bert Meijer accidentally discovered that their liquid solution turned into a hydrogel when diluted. This phenomenon hadn’t been researched or described before and will have consequences in many areas in chemistry and biology. The finding, which appears today in Science Magazine, was made and researched thanks to exceptional teamwork.

Dilution-induced gel-sol-gel-sol transitions by competitive supramolecular pathways in water (no public access)

Powerful new adhesive stays strong from freezing to boiling temperatures

Amazing stuff! This what I call a true superglue!

"... The new adhesive belongs to a class known as supramolecular adhesives, which are made up of molecular components specially designed to self-assemble into strong bonds during curing. One is a ring-shaped molecule called a crown ether, which can wrap around the second component, a small protein produced by bacteria. ...
The team tested it out by gluing steel plates together, and found that they could withstand up to 22 Megapascals of shearing force. Most impressively, that strength worked not only at room temperature but anywhere from -196 °C (-320.8 °F) up to 200 °C (392 °F). It proved promising on other materials as well, and even worked underwater. ...
The tight bond drives water out of the protein, which means that when the temperature drops no ice crystals can form and crack open the material, as often happens with other glues. This could also help explain why it works underwater. ..."

From the abstract:

"A crown-ether-protein adhesive was synthesized by host–guest molecular engineering. The internal dynamic molecular interactions endow the adhesives with extraordinary adhesion performance over a wide temperature range from −196 to 200 °C. Extremely strong adhesion, long-lasting adhesion, and biomedical sealing have been achieved. This work offers a promising molecular engineering strategy to fabricate robust supramolecular adhesives for applications under extreme conditions.

The inherently tenuous adhesion strength and limited environmental tolerance of supramolecular adhesives severely restrict their application scenarios. It is challenging for the development of robust adhesives with extreme temperature tolerance. Herein, we report a new type of temperature-resistant crown-ether-protein (CEP) adhesive by harnessing synergistic host–guest molecular interactions between engineered crown ether and protein building blocks. The outputs of CEP adhesive demonstrate ultrahigh shearing adhesion strength of ≈22 MPa over a wide temperature range from −196 to 200 °C, superior to other established supramolecular or polymeric adhesives. The temperature-induced phase transition and internal bound water stabilized the system and led to superb adhesion under extreme conditions. Thus, this work pioneers a molecular engineering approach for the generation of adhesives with tailored applications in extreme settings."

Powerful new adhesive stays strong from freezing to boiling temperatures

Molecular Engineered Crown-Ether-Protein with Strong Adhesion over a Wide Temperature Range from −196 to 200 °C (no public access)

The hole story of how cage molecules could transform synthesis and separation

Amazing stuff! This approach might have great potential! This is a very recommendable overview article!

"... Molecules twist and fold into unusual shapes to fit inside a nanosized container, concentration increases by factors of up to 10,000, and unstable intermediates become less unstable as they are shielded from the outside world. At the molecular scale, interactions between container and contained molecules become ‘prearranged, prolonged and private’ ...
After 35 years of research, chemists are now starting to unlock the potential of confinement by designing molecular cages that fold up long molecules into huge macrocycles, or creating cavities that can separate deuterium from hydrogen. In the future, confined spaces could rival enzymes in their ability to catalyse reactions or protect unstable species, turning them into useful reagents. ...
One of the most complex transformations ever carried out inside a cage was reported by Ken Raymond, Robert Bergman and Dean Toste, a long-time supramolecular chemistry collaboration at the University of California, Berkeley, US. They used a gallium coordination cage, nicknamed Raymond tetrahedron, to catalyse a three-component coupling reaction.6 More than a simple catalyst, albeit one that increases yields up to 12-fold, the tetrahedron also inverts the reaction’s stereoselectivity. In bulk solution, the product created is the opposite stereoisomer to the one generated inside the cage."

The hole story of how cage molecules could transform synthesis and separation | Research | Chemistry World (behind paywall?)

New Synthetic Molecules Created By Humans

Posted: 6/21/15

Trigger

Eureka moment in supramolecular chemistry. This is the second or so article I have recently read about chemists concocting new, complex molecules with extraordinary stereo properties.

On The Cusp

It appears that humans are about to enter a new era where complex molecules or materials are synthesized that have basically no resemblance to those found in nature. What an exciting time we live in!