Inorganic/organic nanocomposites: Reaching a high filler content without increasing viscosity using core-shell structured nanoparticles

Abstract

International audienceExtensive research is being conducted on the development of inorganic/organic nanocomposites for a wide variety of applications in microelectronics, biotechnologies, photonics, adhesives, or optical coatings. High filler contents are usually required to fully optimize the nanocomposites properties. However, numerous studies demonstrated that traditional composite viscosity increases with increasing the filler concentration reducing therefore significantly the material processability. In this work, we synthesized inorganic/organic core-shell nanocomposites with different shell thicknesses. By reducing the shell thickness while maintaining a constant core size, the nanopar- ticle molecular mass decreases but the nanocomposite filler fraction is correlatively increased. We performed viscosity measurements, which clearly highlighted that intrinsic viscosity of hybrid nanoparticles decreases as the molecular mass decreases, and thus, as the filler fraction increases, as opposed to Einstein predictions about the viscosity of traditional inorganic/polymer two-phase mixtures. This exceptional behavior, modeled by Mark-Houwink-Sakurada equation, proves to be a significant breakthrough for the development of industrializable nanocomposites with high filler contents

Functional and Biomimetic Materials for Engineering of the Three-Dimensional Cell Microenvironment

“…, gold, silver, and iron-oxide nanoparticles), 399–404 polymeric nanoparticles ( e.g. , cyclodextrin and hyper-branched polyester nanoparticles), 405–406 and carbon-based nanostructures ( e.g. , CNTs and graphene).…”

“…Mobility of cross-linking nanoparticles is hypothesized to endow networks with enhanced toughness. − Several successful classes of hybrid hydrogels containing nanoparticles or nanostructures have been developed. These include inorganic and nonmetallic nanoparticles (e.g., hydroxyapatite, calcium phosphate, silica, and silicate nanoparticles), − metal/metal-oxide nanoparticles (e.g., gold, silver, and iron-oxide nanoparticles), − polymeric nanoparticles (e.g., cyclodextrin and hyper-branched polyester nanoparticles), , and carbon-based nanostructures (e.g., CNTs and graphene). − These nanocomposite hydrogels can exhibit enhanced properties such as improved mechanical stiffness and strength and enhanced magnetic responsiveness, electrical conductivity, and optical and thermal properties. , They may provide well-controlled biophysical cues for engineering the cell microenvironment and have been implemented in a wide variety of applications in drug delivery and hyperthermia therapies, as well as proposed theranostic procedures. , However, as described below, these materials are fundamentally limited at present for tissue engineering applications.…”

Scalable methods for directional assembly of fillers in polymer composites: Creating pathways for improving material properties

“…[40,41] In general, the composite properties are collectively determined by the filler type, [42,43] content, [44,45] and composite morphology (i.e., how the filler is assembled in the matrix). [46,47] While a higher loading of fillers is often beneficial, it is important to recognize that increasing filler loading content can lead to several complications including, but not limited to, processing difficulty due to increased viscosity, [48] particle aggregation with macroscopic inhomogeneity, [49][50][51] and diminishment of key features from the polymer matrix (e.g., mechanical flexibility and optical transparency). [52][53][54] Addressing these challenges often requires careful system optimization, which may involve extensive experiments and investigations to fully understand the trade-offs between distinct material properties as a function of filler content.…”

Direct Printing of Thermal Management Device Using Low‐Cost Composite Ink

“…Among these, nanostructured fillers are demonstrating excellent properties due to their high aspect ratio and large surface to volume ratio. Although adding fillers increases thermal conductivity, high filler concentration increases the viscosity of the polymer mixture, which reduces the processability and requires more complicated manufacturing techniques . Therefore, traditional processing methods are restricted to only a few methods, such as casting, hot rolling into thin films, or hot press molding .…”