Understanding the Microstructure Connectivity in Photopolymerizable Aluminum-Phosphate-Silicate Sol-Gel Hybrid Materials for Additive Manufacturing

Author(s)

Tayama, Gabriel Toshiaki ; Santagneli, Silvia Helena ; de Oliveira Jr, Marcos ; Messaddeq, Younes

• Document type: Journal article
• Source: Journal of Physical Chemistry C; v. N/A, p. 14-pg., 2023-01-30.

Abstract

In this paper, we report the synthesis and structural characterization of transparent and photopolymerizable aluminum-phosphate-silicate hybrid materials obtained via the sol-gel route, with different aluminum/phosphate (Al/P) ratios. We explored the system Si(1-x)-(Al/P) (x) with x varying from 0.3 to 1, and atomic ratios of Al/P are 1:3, 1:1, and 3:1. All compositions contain high inorganic mass content (up to 40 wt %). Furthermore, they are compatible with vat-photopolymerization platforms. The structural evolution of the hybrid materials with the silicon concentration was investigated by SEM, phase-contrast AFM, and solid-state NMR techniques, using single-and double-resonance experiments. The structure follows the build-up principle using aluminum phosphate species and alkoxysilane chains as fundamental building blocks. These aluminum-phosphate species were identified as monomeric and dimeric chain structures by comparing different parameters obtained from NMR data to compound models. Monomeric and dimeric aluminum-phosphate chain structures were predominant in 3:1 and 1:3 Al/P ratio samples, respectively, promoting and hindering the heterocondensation with the alkoxysilane precursor, respectively. The photopolymerization mechanism leads to the percolation of the inorganic networks through a parallel polymethylmethacrylate network, resulting in a material with structural heterogeneities in the range of 5 nm, evidenced by phase-contrast AFM. (AU)

• FAPESP's process: 18/24735-3 - The correlation between structure and properties as investigated by multinuclear solid state NMR in disordered materials
• Grantee: Silvia Helena Santagneli
• Support Opportunities: Regular Research Grants
• FAPESP's process: 15/22828-6 - Pushing the boundaries of optical fibers: from photonics to optogenetics and environmental monitoring
• Grantee: Younes Messaddeq
• Support Opportunities: Research Projects - SPEC Program
• FAPESP's process: 18/06426-3 - Development of coacervates for additive manafacturing/3D printing of photonic materials
• Grantee: Gabriel Toshiaki Tayama
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)