While making increasingly smaller electronic, medical and biological devices is convenient for consumers of such technology, it can be difficult for chemical engineers and materials scientists to predict nanoscale molecular interactions and ensure that such systems will work properly.
The reason for this, scientists from the University of Massachusetts Amherst explain, is that the physics of interactions at this level are difficult. However, they report in the latest edition of the journal Langmuir that they have developed a new computational and modeling software tool along with a database system that should make it easier for experts to work with nanoscale materials.
The open-source project is known as Gecko Hamaker, and according to UMass Amherst physics chair Adrian Parsegian, doctoral student Jaime Hopkins, and adjunct professor Rudolf Podgornik, it allows users to access a vast array of different nanometer-level interactions that will help them predict molecular organization and evaluate if new material combinations will actually work.
These calculations pertain to the intermolecular attractions known as van der Waals forces. Van der Waals forces occur between DNA, carbon nanotubes, proteins, and inorganic material, governing interactions that take place at the molecular level. The researchers believe their work may provide new insights into this realm that were previously inaccessible to materials scientists.
Data can benefit a wide array of applications, creators say
“Van der Waals forces are small, but dominant on the nanoscale,” Parsegian explained in a statement. “We have created a bridge between deep physics and the world of new materials. All miniaturization, all micro- and nano-designs are governed by these forces and interactions, as is behavior of biological macromolecules such as proteins and lipid membranes. These relationships define the stability of materials.”
“People can try putting all kinds of new materials together,” he added. “This new database and our calculations are going to be important to many different kinds of scientists interested in colloids, biomolecular engineering, those assembling molecular aggregates and working with virus-like nanoparticles, and to people working with membrane stability and stacking. It will be helpful in a broad range of other applications.”
Materials scientists, the physics chair pointed out, must know whether or not different molecules will stick together. This is a difficult task, so they have to turn to a variety of approaches in order to find out for certain. Gecko Hamaker includes experimental observations that, while apparently unrelated to the issue of interactions, still help evaluate the van der Waals forces’ magnitude.
“Our work is fundamentally different from other approaches, as we don’t talk only about forces but also about torques,” Podgornik said. “Our methodology allows us to address orientation, which is more difficult than simply describing van der Waals forces, because you have to add a lot more details to the calculations. It takes much more effort on the fundamental level to add in the orientational degrees of freedom.”
He added that this methodology enables Gecko Hamaker to address non-isotropic, non-spherical, or other complex molecular shapes. In these instances, he said, simply knowing the forces is not enough – scientists must be able to calculate how torque works on orientation. Their software is capable of providing detailed information on even the most difficult cases, Podgornik noted.
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Feature Image: UMass Amherst
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