May 3 2013
Over recent years, polymer nanocomposites have been extensively researched owing to its potential benefits. These compounds consist of a single-type nanomaterial diffused in a polymer matrix. The purpose of integrating nanomaterials into polymers is to enhance one or more particular aspects of the target material beyond improvements that could otherwise be realized through the use of standard fillers. Although the combination of polymers and nanomaterials was successful to some extent, they proved to be costly and did not perform well when compared to traditional fillers.
Tools to Optimize Nanomaterials
US-based nanomaterials company, Xolve has widened the scope of applications where nanomaterials can achieve significant and cost-effective enhancements. Xolve has developed multiple technical tools to economically exfoliate usual materials into high quality nanomaterials, to improve them for a range of attributes, and then to develop those exfoliated materials into target polymers and keep them exfoliated.
Although Xolve has developed multiple tiers of technology to improve the performance of nanomaterials, the company has also developed the capability to produce interactive networks of multiple nanomaterials that exhibit performance attributes, which are further than the additive contribution of each nanomaterial alone. At present, Xolve is working on its graphite to graphene conversion process to create high quality graphene nanoplatelets in a cost effective way.
Graphene: Wonder Material
Graphene is a single nanomaterial and dissolving such types of materials is a difficult prospect; first dispersion has to be achieved and then needs to be maintained in the target material. Similar to other forms of nanocarbon or other nanomaterials, graphene tends to agglomerate into polymer composites during processing. To overcome this issue, Xolve has designed specific tools to create a wide range of single nanomaterial batches, which provide improved performance attributes at reduced loading versus standard fillers. On the other hand, Xolve discovered that the achievement of dispersion in the target material does not often lead to improved attribute performance.
Allen Clauss, Vice President of R&D for Xolve, informed that a major example of this is the application of graphene nanoplatelets to improve electrical conductivity in polymer composites. “We discovered that the better our graphene dispersion in the target matrix, the poorer the conductivity”, said Clauss. “While it makes sense that the more you spread out the nanoplatelets, the lower the conductivity, with other attributes, such as strength measurements, the better the dispersion, the better theperformance regarding the selected attribute.”
Co-exfoliation Method
To address this inconsistency related to the attainment of conductivity in polymers, Xolve applied its solvation technology to utilize exfoliated graphene to catalyze the exfoliation of carbon nanotubes, thereby creating an interactive network where the ensuing polymer nanocomposite has increased electrical conductivity corresponding to nanomaterial loading, which is higher than the additive contribution of each nanomaterial alone.
Most importantly, the amount of the relatively expensive carbon nanotubes needed to achieve the effect was quite low, thus enabling target conductivity levels to be realized more cost-effectively in contrast to carbon nanotubes alone. Although Xolve is currently testing this co-exfoliation technique with other nanomaterials, its first viable embodiment will be carbon nanotubes and graphene.
Solvation Technology
“While both forms of nanocarbon have similar surface energies”, said Clauss, “they have different particle morphologies—platelets and tubes. It is the combination of our solvation technology with materials of different morphologies that prevents the individual materials from self-agglomerating, and, importantly for electrical conductivity, the nanotubes form bridges between the platelets, dramatically increasing the conductivity of the resulting matrix.”
Xolve informed that in addition to polymers, the technology can also be applied to a wide range of thermoplastics and thermosets. The technology can potentially modify change the thermal and electrical conductivity properties of these materials.
“We are very excited about this latest development in our tool set, which allows us to modify a wide range of attributes in nearly all industrial polymers”, stated John Biondi, President and CEO of Xolve. “Also this latest capability of improving conductivity goes hand in hand with our ability to improve other attributes. While conventional fillers often trade off one attribute to improve another, we can improve multiple attributes simultaneously. We can improve strength and conductivity, for instance.”
Biondi informed that Xolve is applying its conductivity improving capabilities to projects in conductive electronic packaging materials, automotive fuelsystem components, and polymer flow battery electrodes, etc. “Our ability to improve composite material attributes with nanomaterials at a cost structure similar to standard materials has brought us a significant number of projects for a small company”, Biondi said.
Xolve develops and markets polymer master batch materials so as to ensure that customers can benefit from the substantial enhancements of advanced nanomaterials in a form that enables them to do so with conventional tools. “In spite of all the hype around graphene, customers don’t want to buy graphene, they want to buy improvements in their materials so they can solve their customer’s problems. We give them that at a price that competes with standard fillers”, said Biondi.
Conclusion
Xolve is just venturing into the commercialization phase but its optimization strategy presents a practical option to reduce cost and improve the performance of nanomaterials, and in the process deliver products that could revolutionize a wide range of applications.
This information has been sourced, reviewed and adapted from materials provided by Xolve.
For more information on this source, please visit Xolve.