Ionic liquid as Functional Dispersant for Nanomaterials in Polymer Matrix
Jiji Abraham*, Hanna J Mariya and Sabu Thomas
International and Inter University Centre for Nanoscience and Nanotechnology, India
Submission: July 30, 2018; Published: October 09, 2018
*Corresponding author: Jiji Abraham, International and Inter University Centre for Nanoscience and Nanotechnology, Mahatma Gandhi University, India.
How to cite this article: Jiji Abraham, Hanna J M, Sabu T . Ionic liquid as Functional Dispersant for Nanomaterials in Polymer Matrix . Academ J Polym
Sci. 2018; 2(1): 555576. DOI: 10.19080/AJOP.2018.02.555576
Ionic liquid has been used as a novel dispersant for fillers in polymer matrix. Enhanced interfacial interaction between reinforcing material and polymer matrix leads to smart materials. Use of ionic liquid as a modifier is environmentally friendly method to fabricate nanocomposites potential applications.
Potential applications as well as strength and durability of polymers can be enriched by the reinforcement using various nanosized fillers. However wide spread application of nanomaterials as reinforcing agents has limited due to their processing difficulty and the tendency to form agglomerates. Incorporation of active groups on fillers by emerging chemistry is a good method to overcome the problems associated with filler dispersion. At present, many advanced strategies have been developed to improve the dispersibility and stability of nanofillers in solvents and matrices which include (a) the covalent attachment of functional groups through chemical reactions (b) the non-covalent adsorption or wrapping of various functional molecules. Due to some structural alteration and the need of additional solvent during covalent fictionalisation, non-covalent functionalization is preferred.
Non-covalent functionalization of fillers by Room-Temperature Ionic Liquids (RTILs) has got considerable attention in these days. RTILs, usually liquid at or near room temperature are non-volatile, non-flammable and thermally stable. They provide an environmentally benign “green” alternative to organic solvents for chemical synthesis, extractions and bio catalysis .
Use of ionic liquid as novel dispersant for fillers has been developed as an environment friendly technology to functionalize them. Commonly reported dispersants are solid in state which needs additional solvent to disperse nanomaterial. In contrast
ionic liquids are fluid at room temperature and are made entirely of ions (asymmetric cation and a symmetric anion) .
Das et al. first reported the use of ionic liquid as a dispersing agent for Multiwalled Carbon Nanotube (MWCNT) . Cation-π interaction between cationic part of ionic liquid and π conjugated MWCNT surface is the reason behind the dispersion of MWCNT. Since ionic liquid can act a dispersant, it will improve overall performance of the nanocomposites. Researches from the same group had tried different ionic liquids to functionalize MWCNT and studied its effect on various properties of fabricated nanocomposites. These studies showed a clear evidence for the enhanced dispersion of MWCNT in presence of ionic liquid, improved cure characteristics, mechanical performance, dielectric characteristics, electrical conductivity, ionic conductivity, thermal stability, thermal conductivity oxidation resistance, thermo mechanical properties and processability. Flexible and stable electromagnetic shielding materials can be fabricated with the aid of ionic liquid modified MWCNT [4,5].
Studies also reported in the area of dispersing other fillers like graphene, graphite oxide, graphene oxide, clay, layered double hydroxides, silica, carbon black etc. with the aid of ionic liquid. On mixing Graphene Oxide (GO) and ionic liquid, ILs had been effectively intercalated into the interlayer of GO, which was found to be able to raise the exfoliation degree of GO. It is found that both thermal stability and the thermal conductivity of Bromobutyl Rubber (BIIR) nanocomposites could be improved by incorporating the Ionic Liquids (ILs) modified graphene oxide (GO-ILs) .
Tribological study of functionalized graphene-IL nanocomposite
ultrathin lubrication films on Si substrates the promising
applications in the lubrication of micro/nanoelectromechanical
systems (MEMS/NEMS) . It is possible to control the pore
size, electrical conductivity and mechanical robustness of the
polyurethane nanocomposite foam by incorporating it with
modified the graphene oxide using 1-methyl imidazole chloride
ionic liquid . Boron Nitride Nanosheets (BNNS) are exfoliated
with the help of ionic liquid by physical adsorption on IL on BNNS
surfaces. Highly thermally conductive and electrically insulating
polymer nanocomposites can be prepares using this material .
Ionic liquid can be used as interfacial agent or surfactant
or organic modifier for layered double hydroxide in
polymer nanocomposites . Ionic liquids were used as an
environmentally friendly material to improve the processability
of layered silicates containing polymer nanocomposites .
Zwitterionic Imidazolium-Based Ionic Liquid (ZIL) was used to
modify both cationic and anionic clay minerals. The ZIL was able
to penetrate into the interlayer space of clay and modified the
interfacial properties . Studies have been reported on the role
of ionic liquid as an interfacial modifier for silica and as a cure
accelerator in polymer nanocomposites .
In conclusion the use of ILs afforded not only high-yield,
mild, facile exfoliation of various fillers but also non-covalent
functionalization of fillers for multifunctional applications.
Merging processing techniques of nanocomposites with ionic
liquid for efficient dispersion of nanomaterials facilitates the
development of new, high performance materials.