Negative thermal expansion design strategies in metal-organic frameworks

phys.org | 11/5/2015 | Staff
AnnieFoxx (Posted by) Level 3
Click For Photo: https://scx2.b-cdn.net/gfx/news/2019/5d8b4d5fcfe7b.jpg

In a study just published in the renowned journal Advanced Functional Materials, a team of American and Dutch researchers present design strategies for adjusting the thermal expansion behavior of microporous Metal-Organic Frameworks (MOFs). In particular, the ability to realise negative thermal expansion coefficients is of great relevance to the potential application of MOFs—for instance at material interfaces where they could prevent cracking and peeling. Dr. David Dubbeldam and Dr. Jurn Heinen of the University of Amsterdam's Van 't Hoff Institute for Molecular Sciences (HIMS) contributed to the research, that included both experimental work and computer simulation.

In condensed matter, an increase in temperature generally leads to an increase in volume. In applications where materials are placed in confined environments, this phenomenon of positive thermal expansion (PTE) can cause significant stress or even catastrophic device failure. At material interfaces in coatings or films, a mismatch in thermal expansion properties can lead to cracking and peeling. The availability of materials with tailored thermal expansion behavior would mitigate such problems and be of significant value for a variety of other material design and engineering challenges.

Frameworks - MOFs - Expansion - NTE - Part

Metal-organic frameworks (MOFs) are predicted to exhibit widespread negative thermal expansion (NTE), due in part to their nano-porosity and flexible framework characteristics. They are particularly intriguing as NTE materials since they offer great design flexibility—a characteristic which distinguishes them from NTE zeolite materials. MOFs are formed by the assembly of a great variety of inorganic nodes and multitopic organic ligands. The latter also enable a larger degree of structural flexibility which may further promote their potential for exhibiting large-scale NTE.

The MOF design strategies now published in Advanced Functional Materials are the result of a collaborative American/Dutch effort where experimental research at Sandia Labs (Livermore, California, U.S.) and Georgia Tech (Atlanta, Georgia, U.S.) was supported by computer simulations performed by Dr....
(Excerpt) Read more at: phys.org
Wake Up To Breaking News!
Sign In or Register to comment.

Welcome to Long Room!

Where The World Finds Its News!