Ionic liquid as Functional Dispersant for Nanomaterials in Polymer Matrix-Juniper Publishers
JUNIPER
PUBLISHERS- ACADEMIC JOURNAL OF POLYMER SCIENCE
Abstract
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.
Keywords: Ionic liquid; Polymer matrix; Interfacial interaction; Potential applications
Abbrevations:
RTILs: Room-Temperature Ionic Liquids; MWCNT: Multiwalled Carbon
Nanotube; GO: Graphene Oxide; BNNS: Boron Nitride Nanosheets; BIIR:
Bromo butyl Rubber; ILs: Ionic Liquids; GO-ILs: Modified Graphene Oxide;
MEMS/NEMS: Micro/Nanoelectromechanical Systems; ZIL: Zwitterionic
Imidazolium-Based Ionic Liquid
Ionic liquid as a Functional Dispersant for Nanomaterials in Polymer matrix
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 [1].
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) [2].
Das et al. first reported the use of ionic liquid as a
dispersing agent for Multiwalled Carbon Nanotube (MWCNT) [3]. Cation-Ï€
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) [6].
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) [7]. 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 [8]. 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 [9].
Ionic liquid can be used as interfacial agent or surfactant
or organic modifier for layered double hydroxide in
polymer nanocomposites [10]. Ionic liquids were used as an
environmentally friendly material to improve the processability
of layered silicates containing polymer nanocomposites [11].
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 [12]. Studies have been reported on the role
of ionic liquid as an interfacial modifier for silica and as a cure
accelerator in polymer nanocomposites [13].
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.
For more articles in Academic Journal of Polymer
Science please click on:
https://juniperpublishers.com/ajop/index.php
https://juniperpublishers.com/ajop/index.php
Comments
Post a Comment