High performance polymer/BaTiO₃ nanocomposites based on surface-modified metal oxide nanoparticles using functional phosphonic acids for electronic applications

Abstract

Polymer/ceramic nanocomposites provide a means of combining the high permittivities (εr) of metal oxide nanoparticles with the solution-processability and high dielectric strength of polymeric hosts. Simple mixing of nanoparticles and polymers generally results in poor quality nanocomposites due to the agglomeration of nanoparticles and poor miscibility of nanoparticles with host materials. We have shown that surface modification of metal oxide nanoparticles with phosphonic acid-based ligands affords robust surface modification and improves the processiblity and the quality of the resulting nanocomposites. We report on the use of phosphonic-acid modified barium titanate (BaTiO3, BT) nanoparticles in dielectric nanocomposites and their applications to high-energy-density capacitors and solution-processable high permittivity gate insulators in organic field-effect transistors (OFETs). Surface modification of BT nanoparticles enabled the formation of high quality nanocomposite thin films with ferroelectric polymer hosts such as poly(vinylidene fluoride-co-hexafluoropropylene), P(VDF-HFP), with large volume fractions (up to 50 vol. %), which are potentially useful materials for electrical energy storage. Similarly, the use of phosphonic acid-modified BT nanoparticles in cross-linked poly(4-vinylphenol) (PVP) allowed to form gate insulators for OFETs. High quality nanocomposite thin films at high nanoparticle volume fractions (up to 37 vol. %) with a large capacitance density (∼50 nF/cm2) and a low leakage current (10−8 A/cm2) were obtained. Pentacene-based p-type OFETs using these nanocomposites showed a large on/off current ratio (Ion/off 104 ∼ 106). We will also present the results from a recent experimental and theoretical study where the BT nanoparticle volume fraction was systematically varied in P(VDF-HFP) host, εr = 11, to find the optimum permittivity and dielectric strength, which provided a guideline for the optimization of the volume fraction for achieving maximum energy density.

Simultaneous Second Harmonic Generation and Multiphoton Excited Photoluminescence in Samarium-Doped BaTiO3 Nanoparticles Functionalized with Poly(ethylene glycol)

“…The microscopy visualization showed that the cellular morphology observed was comparable to that of the control group. As anticipated, BT:Sm NPs demonstrated heterogeneous levels of aggregation (Figure d, shown by black arrows), as previously reported by others. − The black dots are higher in cells subjected to uncoated BT:Sm NPs than in cells treated with (PEG)-coated BT:Sm NPs. Consequently, the incorporation of PEG would enhance the solubility of these NPs in physiological fluids.…”

A Comprehensive Review on Barium Titanate Nanoparticles as a Persuasive Piezoelectric Material for Biomedical Applications: Prospects and Challenges

“…Atomic or molecular adsorbates including surface ligands [ 101,102 ] and coatings [ 103 ] stabilize the ferroelectricity of nanoscale BaTiO 3 and make it useful to design ferroelectric devices that can operate at the atomic scale. High performance BaTiO 3 nanocomposite materials have been prepared by integrating complementary polymers (polyvinylidene fluoride (PVDF), [ 104,105 ] polyacrylamide, [ 106,107 ] poly(2‐hydroxylethyl methacrylate), [ 108 ] poly(vinylidene fluoride‐hexafluoro propylene) (P(VDF‐HFP)), [ 109,110 ] 2‐[2‐(2‐methoxyethoxy) ethoxy]ethyl} phosphonic acid (PEGPA) [ 102,111 ] with BaTiO 3 . These nanocomposites offer superior performance, processability, and scalability than the pure BaTiO 3 nanostructures.…”

“…BaTiO 3 NPs have high surface energy and large surface area which tend to form large aggregates when there are dispersed in aqueous media. [ 111,175 ] Hence these next decades, the hydroxylation of pristine BaTiO 3 surface became a common surface activation method before any surface modification such as functional ligand or core–shell formation with metallic element. [ 81,83,176–178 ]…”

Dielectric property of modified barium titanate/polyamide 11 nanocomposites with different surfactants

“…Common methods are surface modifier, such as phosphate ester surfactants, silane coupling agent, and polydopamine (PDA) . For instance, Kim reported that BT nanocomposites modified with phosphonic acid ligands leaded to well‐dispersed BT nanocomposite films, which had high dielectric constant, dielectric strength, and energy‐storage capacity. Ramajo studied the influence of silane coupling agents on the microstructure and dielectric behavior of epoxy/BaTiO 3 composites.…”