Mechanics of Platelet-Reinforced Composites Assembled Using Mechanical and Magnetic Stimuli

Abstract

Current fabrication technologies of structural composites based on the infiltration of fiber weaves with a polymeric resin offer good control over the orientation of long reinforcing fibers but remain too cumbersome and slow to enable cost-effective manufacturing. The development of processing routes that allow for fine control of the reinforcement orientation and that are also compatible with fast polymer processing technologies remains a major challenge. In this paper, we show that bulk platelet-reinforced composites with tailored reinforcement architectures and mechanical properties can be fabricated through the directed-assembly of inorganic platelets using combined magnetic and mechanical stimuli. The mechanical performance and fracture behavior of the resulting composites under compression and bending can be deliberately tuned by assembling the platelets into designed microstructures. By combining high alignment degree and volume fractions of reinforcement up to 27 vol %, we fabricated platelet-reinforced composites that can potentially be made with cost-effective polymer processing routes while still exhibiting properties that are comparable to those of state-of-the-art glass-fiber composites.

Cement-based composites reinforced with localized and magnetically oriented Al2O3 microplatelets

“…Since the increase in flexural modulus partially results from a decrease in the composite's porosity level of the aligned architecture, more striking is the improvement in flexural strength and strain energy as the effect of porosity was found to be negligible on these two mechanical properties. This result suggests that alignment prevents the platelets from introducing strength-determining critical defects in the brittle cement matrix, which is in agreement with previous results obtained for the same platelets in polyurethane-based [16] and epoxy-based matrices [17]. Localization of the platelets at the bottom of the sample, which is the part of the sample subjected to the highest tensile stresses, also leads to a 48% improvement of both the flexural modulus and the flexural strength as compared to the specimen with the random distribution of platelets.…”

“…The magnetic susceptibility of diamagnetic microplatelets is increased through the adsorption of superparamagnetic iron oxide nanoparticles (SPIONs) on their surface. While this approach has led to polymer-based composites with unusual microstructures and properties [15][16][17], it remains to be exploited in purely inorganic systems exhibiting a relatively high apparent viscosity as is the case for cementitious systems.…”

Role of the polymer phase in the mechanics of nacre-like composites

“…Although many pathways have been suggested to prepare artificial nacreinspired composites, only a few offer the possibility to vary the polymer properties without an impact on the mineral phase (Behr et al, 2015;Bonderer et al, 2008;Bouville et al, 2014;Deville et al, 2006;Ekiz et al, 2009;Erb et al, 2012;Libanori et al, 2013;Podsiadlo et al, 2007;Tang et al, 2003). Infiltrating porous ceramic scaffolds with an organic phase is a possible approach since the production of the two phases can be controlled separately.…”

Ceramic–polymer composites with improved dielectric and tribological properties for semi-active damping

“…The alignment of the magnetised platelets is performed by applying simultaneously a vertical magnetic field and mechanical vibration using a shaking table operated at maximum power [12]. After hardening at room temperature the samples were placed in an oven at 40 C for three hours as recommended by the epoxy resin supplier to increase the degree of cross-linking and ensure a complete hardening (see Fig.…”