The primary objective of this study was to investigate the role of processing methods on the dispersion of unfunctionalized Laponite in latex and the property enhancements of nanocomposite. Processing methods used to disperse Laponite included planetary shear mixing (PSM), ultrasonication, and hand-mixing. Two complimentary characterization techniques were used to evaluate the dispersion of the Laponite in nanocomposite samples: Confocal laser scanning microscopy and transmission electron microscopy (TEM). Nanocomposites processed using PSM showed the least agglomeration of Laponite, followed by hand mixing and ultrasonication. Cryo TEM of latex showed a honeycomb structure with the center of honeycomb occupied by the latex particles, while the nanocomposite showed Laponite nanoparticles surrounding the exterior of the latex particle. Hygrostability studies showed that the average saturated moisture adsorbed by the nanocomposite is strongly dependent on the sample thickness, laponite loading and the processing condition adopted in mixing Laponite with the latex Among all the processed nanocomposites, the thermo-mechanical performance of PSM processed nanocomposite showed the least decrease in modulus compared to latex. These results can have a strong bearing on the design of next generation adhesives.

The polymer nanocomposite delivery platform has drawn a surge in interest in recent years especially in the field of pharmaceutics. Here we present an overview of a LAPONITE®-based nanoparticle drug delivery system (NDDS) along with LAPONITE®'s physicochemical properties, drug encapsulation efficiency, and the factors influencing drug release, biodegradability, and stability. The underlying interaction and chemistry between LAPONITE®, polymer and drug has been comprehensively covered. We present evidence of various triggering factors, such as pH, temperature, light, and magnetic fields, that facilitate the release of drugs from LAPONITE® nanocarriers. Examples of the use of LAPONITE®-based nanocomposites in the delivery of several types of therapeutics (anticancer, antibiotic, and anti-inflammatory), macromolecules and proteins are highlighted as related to biomedical applications. Several recommendations are discussed, including the potential to develop multifunctional, stimuli-responsive LAPONITE® nanocarriers for smart and controlled delivery of drugs. Finally, we discuss future directions, emphasizing the potential of multifunctional, stimuli-responsive LAPONITE® nanocarriers to enable smart, controlled drug delivery, offering promising avenues for the treatment of chronic diseases.

Polymer nanocomposites can be tuned to achieve exceptional dielectric properties compared to pristine dielectric polymers. To significantly enhance these properties, research has focused on modifying the structure of polymergrafted nanoparticles. However, while much attention has been given to the shell architecture of these nanoparticles, the effects of core size (near de Broglie length) and loading amount on the breakdown strength and energy density of nanocomposites remain less explored. In this study, we synthesized polystyrene grafted TiO2 nanoparticles (PSgTiO2 NPs) using surface-initiated atom transfer polymerization (SI-ATRP) with variable core sizes (15 and 40 nm). By adjusting the monomer-to-nanoparticle feed ratio, we controlled the graft density and molecular weight of the grafted chains. When dispersed in a PS matrix at various loading levels, PSgTiO2 NPs showed minimal improvement in energy density up to 5 wt%. However, significant enhancements were observed at 10 wt% and 20 wt% PSgTiO2 NPs in the PS matrix. Interestingly, for similar loading levels, the energy density and efficiency of 40 nm PSgTiO2 NPs in the PS matrix were higher compared to the 15 nm PSgTiO2 NPs. These findings on core size and nanoparticle loading amount have important implications for the design of commercial dielectric capacitors.

The demand for energy storage devices with high energy density, power density, and higher efficiencies has motivated researchers to explore novel materials and designs beyond current limitations. Polymer-based dielectric capacitors are flexible, lightweight, self-healable, and compatible with a variety of nanofillers. Despite a plethora of studies on polymer nanocomposites with 2D nanofillers, the role of multilayered 2D nanofillers in polymer nanocomposites in the context of energy storage properties has yet to be determined. In this work, mechanically exfoliated 2D mica nanofillers were incorporated with poly(vinylidene fluoride) (PVDF) polymer to fabricate PVDF-mica-PVDF (PMP) multilayered heterostructure capacitors. A single exfoliated layer of mica with an average thickness of the flakes of 20 nm interfaced within layers of PVDF to form PMP and using two layers of mica to form PVDF/mica/PVDF/mica/PVDF (PMPMP) heterostructure capacitors. Average enhancements of 100% and 170% were measured for the dielectric constants of PMP (epsilon(av) similar to 22.9) and PMPMP (epsilon(av) similar to 30.8), respectively compared to that of the pristine PVDF (epsilon(av) similar to 11.4) films measured using the same setup. The highest discharged energy density of PMP and PMPMP nanocomposite films reached 27.5 J/cm(3) (E = 670 MV/m) and 44 J/cm(3) (E = 570 MV/m), compared to 11.2 J/cm(3) (E = 396 MV/m) for the pristine PVDF capacitor. This work develops a detailed understanding of the use of multilayered 2D nanofillers to develop high-capacitance and high energy density polymeric dielectric capacitors and opens avenues for developing orientation-controlled 2D nanofiller-based capacitors for use in industrial applications.

Nanocomposites provides a unique opportunity to enhance thermal, mechanical, and waterproof resistance properties of polymer. The effectiveness of these enhancements typically depends on the optimal dispersion and interaction of nanofillers within the polymer matrix. The primary objective of this study is to provide direct chemical evidence for electrostatic interactions between Laponite nanofiller and polyacrylic acid. Samples were prepared by mixing Laponite dispersion and aqueous polyacrylic acid (PAA) that were adjusted to various pH conditions. We observed, an IR peak shift in the carbonyl peak of PAA and Si-O peak of Laponite to lower wave number in nanocomposite, with the maximum shift at pH 7. UV-Vis results also showed a hypsochromic shift in the carbonyl peak of PAA due to the interaction with Laponite. The extent of peak shift in IR, and UV-Vis region for the PAA-Laponite dispersion was found to be influenced by the molar mass of PAA used in the formulation of Laponite-PAA nanocomposite and pH of the medium. These results along with zeta potential measurements strongly suggest that electrostatic forces are in play between deprotonated PAA and the positively charged rim of Laponite in promoting electrostatic interactions between Laponite and PAA. The findings of the study can have a strong bearing on the design of next generation high performance coatings, sealants, and adhesives.

Structurally well-defined polymer-grafted nanoparticle hybrids are highly sought after for a variety of applications, such as antifouling, mechanical reinforcement, separations, and sensing. Herein, we report the synthesis of poly(methyl methacrylate) grafted- and poly(styrene) grafted-BaTiO3 nanoparticles using activator regeneration via electron transfer (ARGET ATRP) with a sacrificial initiator, atom transfer radical polymerization (normal ATRP), and ATRP with sacrificial initiator, to understand the role of the polymerization procedure in influencing the structure of nanoparticle hybrids. Irrespective of the polymerization procedure adopted for the synthesis of nanoparticle hybrids, we noticed PS grafted on the nanoparticles showed moderation in molecular weight and graft density (ranging from 30,400 to 83,900 g/mol and 0.122 to 0.067 chain/nm2) compared to PMMA-grafted nanoparticles (ranging from 44,620 to 230,000 g/mol and 0.071 to 0.015 chain/nm2). Reducing the polymerization time during ATRP has a significant impact on the molecular weight of polymer brushes grafted on the nanoparticles. PMMA-grafted nanoparticles synthesized using ATRP had lower graft density and considerably higher molecular weight compared to PS-grafted nanoparticles. However, the addition of a sacrificial initiator during ATRP resulted in moderation of the molecular weight and graft density of PMMA-grafted nanoparticles. The use of a sacrificial initiator along with ARGET offered the best control in achieving lower molecular weight and narrow dispersity for both PS (37,870 g/mol and PDI of 1.259) and PMMA (44,620 g/mol and PDI of 1.263) nanoparticle hybrid systems.

Designing high energy density dielectric capacitors for advanced energy storage systems needs nanocomposite-based dielectric materials, which can utilize the properties of both inorganic and polymeric materials. Polymer-grafted nanoparticle (PGNP)-based nanocomposites alleviate the problems of poor nanocomposite properties by providing synergistic control over nanoparticle and polymer properties. Here, we synthesize "core-shell" barium titanate-poly(methyl methacrylate) (BaTiO3-PMMA) grafted PGNPs using surface-initiated atom transfer polymerization (SI-ATRP) with variable grafting densities of (0.303 to 0.929) chains/nm2 and high molecular masses (97700 g/mL to 130000 g/mol) and observe that low grafted density and high molecular mass based PGNP show high permittivity, high dielectric strength, and hence higher energy densities (≈ 5.2 J/cm3) as compared to the higher grafted density PGNPs, presumably due to their "star-polymer"-like conformations with higher chain-end densities that are known to enhance breakdown. Nonetheless, these energy densities are an order of magnitude higher than their nanocomposite blend counterparts. We expect that these PGNPs can be readily used as commercial dielectric capacitors, and these findings can serve as guiding principles for developing tunable high energy density energy storage devices using PGNP systems.

Dielectric capacitors are critical components in electronics and energy storage devices. The polymer based dielectric capacitors have advantages of flexibility, fast charge and discharge, low loss, and graceful failure. Elevating the use of polymeric dielectric capacitors for advanced energy applications such as electric vehicles (EVs) however requires significant enhancement of their energy densities. Here, we report a polymer thin film heterostructure based capacitor of poly(vinylidene fluoride)/poly(methyl methacrylate) with stratified 2D nanofillers (Mica or h-BN nanosheets) (PVDF/PMMA-2D fillers/PVDF), that shows enhanced permittivity, high dielectric strength and an ultra-high energy density of 75 J/cm3 with efficiency over 79%. Density functional theory calculations verify the observed permittivity enhancement. This approach of using oriented 2D nanofillers based polymer heterostructure composites is expected to be universal for designing high energy density thin film polymeric dielectric capacitors for myriads of applications.

High‐energy‐density storage devices play a major role in modern electronics from traditional lithium‐ion batteries to supercapacitors for a variety of applications from rechargeable devices to advanced military equipment. Despite the mass adoption of polymer capacitors, their application is limited by their low energy densities and low‐temperature tolerance. Polymer nanocomposites based on 2D nanomaterials have superior capacitive energy densities, higher thermal stabilities, and higher mechanical strength as compared to the pristine polymers and nanocomposites based on 0D or 1D nanomaterials, thus making them ideal for high‐energy‐density dielectric energy storage applications. Here, the recent advances in 2D‐nanomaterial‐based nanocomposites and their implications for energy storage applications are reviewed. Nanocomposites based on conducting 2D nanofillers such as graphene, reduced graphene oxide, MXenes, semiconducting 2D nanofillers including transition metal dichalcogenides such as MoS2, dielectric 2D nanofillers including hBN, Mica, Al2O3, TiO2, Ca2Nb3O10 and MMT, and their effects on permittivity, dielectric strength, capacitive energy density, efficiency, thermal stability, and the mechanical strength, are discussed. Also, the theory and machine‐learning‐guided design of polymer 2D nanomaterial composites is learnt and the challenges and opportunities for developing ultrahigh‐capacitive‐energy‐density devices based on these nanofiller polymer composites are presented.

The maximum capacitive energy stored in polymeric dielectric capacitors, which are ubiquitous in high-power-density devices, is dictated by the dielectric breakdown strength of the dielectric polymer. The fundamental mechanisms of the dielectric breakdown, however, remain unclear. Based on a simple free-volume model of the polymer fluid state, we hypothesized that the free ends of linear polymer chains might act as "defect" sites, at which the dielectric breakdown can initiate. Thus, the dielectric breakdown strength of cyclic polymers should exhibit enhanced stability in comparison to that of their linear counterparts having the same composition and similar molar mass. This hypothesis is supported by the ∼50% enhancement in the dielectric breakdown strength and ∼80% enhancement in capacitive energy density of cyclic polystyrene melt films in comparison to corresponding linear polystyrene control films. Furthermore, we observed that cyclic polymers exhibit a denser packing density than the linear chain melts, an effect that is consistent with and could account for the observed property changes. Our work demonstrates that polymer topology can significantly influence the capacitive properties of polymer films, and correspondingly, we can expect polymer topology to influence the gas permeability, shear modulus, and other properties of thin films dependent on film density.

The synthesis of polymer-grafted nanoparticles (PGNPs) or hairy nanoparticles (HNPs) by tethering of polymer chains to the surface of nanoparticles is an important technique to obtain nanostructured hybrid materials that have been widely used in the formulation of advanced polymer nanocomposites. Ceramic-based polymer nanocomposites integrate key attributes of polymer and ceramic nanomaterial to improve the dielectric properties such as breakdown strength, energy density and dielectric loss. This review describes the "grafting from" and "grafting to" approaches commonly adopted to graft polymer chains on NPs pertaining to nano-dielectrics. The article also covers various surface initiated controlled radical polymerization techniques, along with templated approaches for grafting of polymer chains onto SiO2, TiO2, BaTiO3, and Al2O3 nanomaterials. As a look towards applications, an outlook on high-performance polymer nanocomposite capacitors for the design of high energy density pulsed power thin-film capacitors is also presented.

Nanocomposite hydrogels are attracting significant interest due to their potential use in drug delivery systems and tissue scaffolds. Stimuli-responsive hydrogel nanocomposites are of particular interest due to sustained release of therapeutic agents from the hydrogel. However, challenges such as controlled release of therapeutic agents exist because of limited understanding of the interactions between the therapeutic agent and the hydrogel. To investigate the interaction, we synthesize a hydrogel nanocomposite by crosslinking the hydrogel precursors (tetrazine-modified polyethylene glycol and norbornene-modified hyaluronic acid) using click chemistry while bovine serum albumin-capped silver nanoparticles were encapsulated in situ in the matrix. The interaction between the nanoparticles and the hydrogel was studied by a combination of spectroscopic techniques. X-ray photoelectron spectroscopy results suggest that the hydrogel molecule rearranges so that polyethylene glycol is pointing up toward the surface while hyaluronic acid folds to interact with bovine serum albumin of the nanoparticles. Hyaluronic acid, facing inward, may interact with the nanoparticle via hydrogen bonding. The hydrogel nanocomposite showed antibacterial activity against Gram-positive/Gram-negative bactericides, supporting time-based nanoparticle release results. Our findings about interactions between the nanoparticles and the hydrogel can be useful in the formulation of next generation of hydrogel nanocomposites.

This review provides a detailed overview of the latest developments using nanoscale strategies in the field of polymeric and polymer nanocomposite materials for emerging dielectric capacitor-based energy storage applications. Among the various energy storage devices, solid-state dielectric capacitors possess the advantage of high-power density which makes them highly attractive for pulsed power applications. Polymers are particularly suitable for dielectric energy storage applications because of their high breakdown strength, low dielectric loss, formability, self-healing capability, flexibility, solvent processability, and graceful breakdown failure. Strategies to enhance the dielectric breakdown strength of polymeric dielectric capacitors are emphasized in this review. General background on breakdown mechanism, breakdown characteristics, and factors influencing polymer dielectrics breakdown are introduced. Given that polymers have low permittivity, strategies to substantially enhance dipole mobility and hence the permittivity, are highlighted. We discuss strategies to address permittivity contrast between nanofillers and the polymer matrix including the potential for developing gradient permittivity structured nanofillers. To improve the compatibility of nanofiller with polymer and minimize nanofiller aggregation, different routes to surface functionalize nanoparticles are presented. An outlook and future perspectives section are provided for the design of high energy density polymer film capacitors.

Two-dimensional (2D) van derWaals layered materials created new avenue for the last decade in the field of optoelectronics for showing promising new and diverse applications. Strong light-matter interaction properties on these materials in single to few atomic layer form realized promising thinnest possible photovoltaic solar cells. Over the past few years, optoelectronics properties such as field-effect transistors, photodiodes, memory devices, optical switching, and excitonic physics of these materials have been intensively explored which indicates great potential for photovoltaic applications. Here, we reviewed the recent progress on photovoltaic solar cells of these 2D materials and their heterostructures with different device configurations. The p-n junction solar cells of vertical and lateral configuration devices are discussed in detail based on their stacking using mechanical transfer method or fabricated using CVD technique. The performance of each device configurations was also discussed based on their charge collection efficiency. In addition, we discussed the challenges and limitation of these photovoltaic solar cells and the possible routes to enhance the efficiency for future practical applications.

Block copolymers (BCPs) have received significant attention as promising candidates for sequestering nanoparticles and fabrication of aligned nanostructures with optimal optical or electrical properties. We investigate the influence of static and dynamic thermal field on the alignment of polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA) BCP morphology with the loading of novel poly(methyl methacrylate-block-Polystyrene) (PMMA-b-PS)-grafted-TiO2 nanoparticles (BCP-g-TiO2). Observation of characteristics IR peaks for PMMA and PS in BCP-g-TiO2 nanoparticles and Transmission Electron Microscopy (TEM) results of the outer coating of core nanoparticle, validate the grafting to approach in synthesizing BCP-g-TiO2. Here we report that under the sharp dynamic thermal field, at low loading of BCP-g-TiO2, there is good dispersion of nanoparticles in unidirectionally aligned BCP matrix in film interior probed by GISAXS, while, at high nanoparticle loading (similar to 10 wt%), there is local frustration in the unidirectional alignment of the BCP matrix due to aggregation of BCP-g-TiO2 nanoparticles. However, Grazing incidence small angle X-ray scattering (GISAXS) shows clearly that the BCP films remain largely locally ordered at the domain scale, despite these large perturbations to long-range ordering even at high loading level, while bringing in new TiO2 functionality to the BCP films, such as UVO absorptivity or biofouling prevention, important to potential new applications of such membranes.

Among the layered two dimensional semiconductors, molybdenum disulfide (MoS2) is considered to be an excellent candidate for applications in optoelectronics and integrated circuits due to its layer-dependent tunable bandgap in the visible region, high ON/OFF current ratio in field-effect transistors (FET) and strong light-matter interaction properties. In this study, using multi-terminal measurements, we report high broadband photocurrent response (R) and external quantum efficiency (EQE) of few-atomic layered MoS2 phototransistors fabricated on a SiO2 dielectric substrate and encapsulated with a thin transparent polymer film of Cytop. The photocurrent response was measured using a white light source as well as a monochromatic light of wavelength λ = 400 nm-900 nm. We measured responsivity using a 2-terminal configuration as high as R = 1 × 103 A W-1 under white light illumination with an optical power Popt = 0.02 nW. The R value increased to 3.5 × 103 A W-1 when measured using a 4-terminal configuration. Using monochromatic light on the same device, the measured values of R were 103 and 6 × 103 A W-1 under illumination of λ = 400 nm when measured using 2- and 4-terminal methods, respectively. The highest EQE values obtained using λ = 400 nm were 105% and 106% measured using 2- and 4-terminal configurations, respectively. The wavelength dependent responsivity decreased from 400 nm to the near-IR region at 900 nm. The observed photoresponse, photocurrent-dark current ratio (PDCR), detectivity as a function of applied gate voltage, optical power, contact resistances and wavelength were measured and are discussed in detail. The observed responsivity is also thoroughly studied as a function of contact resistance of the device.

Polymer nanocomposites (PNC) have attracted enormous scientific and technological interest due to their applications in energy storage, electronics, biosensing, drug delivery, cosmetics and packaging industry. Nanomaterials (platelet, fibers, spheroids, whiskers, rods) dispersed in different types of polymer matrices constitute such PNC. The degree of dispersion of the inorganic nanomaterials in the polymer matrix, as well as the structured arrangement of the nanomaterials, are some of the key factors influencing the overall performance of the nanocomposite. To this end, the surface functionalization of the nanomaterials determines its state of dispersion within the polymer matrix. For energy storage and electronics, these nanomaterials are usually chosen for their dielectric properties for enhancing the performance of device applications. Although several reviews on surface modification of nanomaterials have been reported, a review on the surface functionalization of nanomaterials as it pertains to polymer dielectrics is currently lacking. This review summarizes the recent developments in the surface modification of important metal oxide dielectric nanomaterials including Silicon dioxide (SiO2), titanium dioxide (TiO2), barium titanate (BaTiO3), and aluminum oxide (Al2O3) by chemical agents such as silanes, phosphonic acids, and dopamine. We report the impact of chemical modification of the nanomaterial on the dielectric performance (dielectric constant, breakdown strength, and energy density) of the nanocomposite. Aside from bringing novice and experts up to speed in the area of polymer dielectric nanocomposites, this review will serve as an intellectual resource in the selection of appropriate chemical agents for functionalizing nanomaterials for use in specific polymer matrix so as to potentially tune the final performance of nanocomposite.

Block copolymers are considered to be highly attractive materials with regards to future applications of nanomaterials and nanostructures owing to their self-assembling nature. Block copolymers, when supplied with sufficient energy, phase separate at the nanoscales to form periodically ordered structures in the nanometer-scale range. A diversity of architectures can be accessed via composition control of individual block components. An exciting area of application for block copolymer self assembly is organic photovoltaic devices (OPV's) where it is expected that the very high interfacial area of the blocks with ~10-20 nm domain spacing would be highly advantageous for exciton diffusion and separation. For this purpose BCPs composed of amorphous (non-conjugated) polymers can also serve as a template for directed assembly of nanoparticles. Zone annealing is a well established method predominantly utilized for metallurgical and semi-conductor purification processes, where recrystallization and oriented grain growth occur on the planar front formed by the cooling-edge of the zone. We have previously applied this process to create highly ordered BCP cylinders that are parallel to the substrate with orientational control, long range order and faster ordering kinetics than conventional thermal annealing. In the present paper, we extend this idea to block copolymer -[6,6]-phenyl-C61-butyric acid methyl ester (PCBM) blend system and report how the presence of PCBM nanoparticles influence the micro-phase separation behavior of cylinder forming poly(styrene-b-2-vinyl pyridine) under a dynamic thermal gradient field. A range of scattering techniques have been on the BCP:PCBM blend system, including grazing incidence small angle x-ray scattering (GISAXS) experiments to characterize in-plane and lateral ordering of BCP-PCBM blend system.