Zyvex Technologies Published Academic Papers

 

1. Carbon Nanotube-enhanced Composite Materials

Abstract

Non covalent functionalization by π stacking was accomplished by treating multi walled carbon nanotubes (MWNTs) through the use of Kentera™, a conjugate rigid rod polymer. The functionalized MWNTs were then introduced into the epoxy resins through a combination of shear and elongation forces. The resulting epoxy resin (containing MWNTs) was then impregnated with carbon fiber under hot-melt conditions to produce epoxy prepreg. Composites were fabricated from both epoxy resin and prepreg by hand lay ups and cured in autoclave. Mechanical testing showed about 50% and 25% improvements in flexural strength and modulus respectively. Furthermore, SEM, DMA, and mechanical test data of the composites suggested formation of strong interfacial bonding between the MWNTs, epoxy matrix and carbon fiber.

Download Full Text

Carbon Nanotube-enhanced Composite Materials (PDF)

 

2. Homogeneous Carbon Nanotube Polymer Composites for Electrical Applications

Abstract

Homogeneous carbon nanotube/polymer composites were fabricated using noncovalently functionalized, soluble single-walled carbon nanotubes (SWNTs). These composites showed dramatic improvements in the electrical conductivity with very low percolation threshold (0.05–0.1 wt% of SWNT loading). By significantly improving the dispersion of SWNTs in commercial polymers, we show that only very low SWNT loading is needed to achieve the conductivity levels required for various electrical applications without compromising the host polymer’s other preferred physical properties and processability. In contrast to previous techniques, our method is applicable to various host polymers and does not require lengthy sonication.

Download Full Text

Homogeneous Carbon Nanotube Polymer Composites for Electrical Applications (PDF)

 

3. Kentera - Noncovalent Engineering of Carbon Nanotube Surfaces by Rigid, Functional Conjugated Polymers

Abstract

Molecular engineering (cutting, solubilization, chemical functionalization, purification, manipulation, and assembly) of single-walled carbon nanotubes (SWNTs) will play a vital role in exploring and developing their applications.1 Noncovalent functionalization of carbon nanotubes is of particular interest, because it enables one to tailor their properties while still preserving nearly all of the nanotube’s intrinsic properties. SWNTs have been solubilized in organic solvents and water by polymer wrapping2 and noncovalently functionalized by adhesion of small molecules for protein immobilization.3 This work reports a new nonwrapping approach to noncovalent engineering of carbon nanotube surfaces that leads to a >20-fold enhancement of solubility of small diameter SWNTs and enables superior control of the relative placement of functionalities on the nanotube surface.

Download Full Text

Kentera - Noncovalent Engineering of Carbon Nanotube Surfaces by Rigid, Functional Conjugated Polymers (PDF)

 

4. Carbon Nanotube-Induced Planarization of Conjugated Polymers in Solution

Abstract

The understanding of the conformational interaction between conjugated polymers and carbon nanotubes in solution is essential to develop the applications of carbon nanotubes, particularly conjugated polymer-carbon nanotube hybrid materials. The visible absorption spectroscopic study shows that curved carbon nanotube surfaces can induce the planarization of individual conjugated polymers such as poly(p-phenyleneethynylene)s and poly(3- alkylthiophene)s in solution. The impact of nanotube surface quality on the interaction between carbon nanotubes and conjugated polymers is investigated.

Download Full Text

Carbon Nanotube-Induced Planarization of Conjugated Polymers in Solution (PDF)

 

5. Non-covalent functionalization through Kentera

Abstract

Functionalization of Carbon Nanotubes (CNTs) has helped in realizing the great potential of carbon nanotechnologies. Zyvex has developed a versatile non-damaging functionalization technology using rigid rod conjugate polymers, poly (aryleneethynylenes) (PAEs) called KenteraTM. The interaction between Kentera and CNT is through π stacking, this occurs through the delocalized π electrons present in both CNT and backbone of Kentera polymer. Although π- π interaction is a weaker bond than covalent bonding, the sum of π-π interactions creates a large net-stabilizing energy that results in superior and stable systems. NMR, fluorescence and UV-Vis spectroscopy were used to establish the formation of a strong molecular complex. The spectroscopic evidence and molecular modeling have shown the interaction between CNT and Kentera is not a simple mixture but forms an irreversible complex comparable to covalent bonds. Molecular mechanics and molecular dynamics have shown the adsorption energies between CNT and Kentera is two times higher when compared to the adsorption energies between CNT. Lastly, Kentera functionalization allows control over the distance between functional groups on the carbon nanotube surface, through variation of the polymer backbone and side chains. The review presented here will highlight all our findings and demonstrates the efficacy of non-covalent functionalization of CNTs. 

Download Full Text

Non-covalent functionalization through Kentera (PDF)