There is a great deal of interest in the use of photoluminescent materials for information security. Several anti-counterfeit technologies have been created, including luminous printing, 2D coding, and watermarking. Common fluorescent materials, however, are monochromatic and easy to counterfeit.
A group of scientists from Chinese Academy of Sciences‘ The Suzhou Institute of Biomedical Engineering and Technology (SIBET) created a nanocomposite material with an iridescent glow using a simple hydrothermal method. They created a Si-based luminescent substance using silane as a precursor and put it to use in the field of information security.
Journal of Chemical Engineering publish findings.
Due to their unique glow characteristics, materials exhibiting room temperature fluorescence (RTP) have been extensively exploited in lighting, bioimaging, and information security.
Conventional synthesis methods mainly use inorganic compounds containing rare earth ions or complexes with noble metals to provide residual light, which inevitably leads to high biological toxicity and expensive synthesis.
Wenfei Dong, Principal Investigator of the Study and Professor, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences
According to Dong, two conditions must be met: a stable rigid structure that stabilizes the excited triplet state of the exciplex, and an effective intersystem crossing of the exciplex.
In light of this, the researchers decided to use 3-Aminopropyl triethoxysilane (APTES) and N-(3-(Trimethoxysilyl)propyl)ethylenediamine (DAMO) as Si sources and other precursors to prepare optically stable cyan and yellow RTP materials.
A one-step hydrothermal approach was used for the preparation procedure, which not only manages to avoid the drawbacks of the two-step method but also more easily generates nanodots in situ and immobilizes them in the matrix.
This newly devised anti-counterfeiting tactic can be used in situations involving high levels of encryption where only interference information is acquired in UV and afterglow irradiation modes, and where filter assistance is required to properly read encrypted content, allowing for better concealment from the correct information.
Given the universality of this method, this standard strategy not only highlights the potential for preparing multifunctional fluorescent materials from silane, but also provides new design principles for the synthesis of fully colored incandescent materials.
Dr Minghui Zan, Corresponding Author of the Study, Wuhan University
This study provides fresh design ideas and insights for the development of silicon-based fluorescent materials for cutting-edge applications as well as a proof of concept for the synthesis of multi-colored fluorescent materials utilizing silane.
The study was funded by the National Key R&D Program of China, the National Natural Science Foundation of China, and the High-Level Entrepreneurship and Innovation Talent Recognition Plan of Jiangsu Province.
Liu, Y., et al. (2023) Multi-Color Room Temperature Fluorescent Silicon-Nanodot Based Nanocomposites with silane tuning and applications for 5D information encryption. Journal of Chemical Engineering. doi:10.1016/j.cej.2023.144349.