Homogeneous nanofillers for enhanced mechanical connection and improved refractive index: application for optical bonding

ABSTRACT

Composite materials with inorganic nanoparticles were systematically investigated to prepare a highly functional composite. This study reports poly(acrylic acid) (PAA) and CaCO₃ nanoparticle complexes (noted as PAA-CaCO₃) that were layer-by-layer (LbL) assembled with poly(allylamine hydrochloride) (PAH) to produce (PAH/PAA-CaCO₃)*n adhesive films with n deposition layers of PAH/PAA-CaCO₃(n is the number of deposition cycles). Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) demonstrated that CaCO₃ nanoparticles were homogeneously dispersed in (PAH/PAA-CaCO₃)*n adhesive films. Polyelectrolytes repeat the “in-and-out” diffusion processes in adhesive films by exponentially growing the LbL assembly, which well disperses CaCO₃ nanoparticles. Adhesive films exhibited high adhesive strength, even reaching 3.76 ± 0.67 MPa when the content of the CaCO₃ nanoparticles reached 70 mol%. The results demonstrated sufficient adhesion performance for use as an adhesive in advanced optical applications. Optical transmittances of adhesive films were all greater than 87% in the visible light range. Furthermore, the refractive index (RI) increased from 1.5332 to 1.5450 with increasing CaCO₃ nanoparticles content.

Graphical Abstract

KEYWORDS:

• Nanofiller
• refractive index
• layer-by-layer assembly
• optical bonding

Acknowledgements

This work was supported by National Natural Science Foundation of China (Grant No. 21504008).

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Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

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Funding

This work was supported by the National Natural Science Foundation of China [21504008].