Introduction
Fluorescent materials have the property allow them re-radiate the energy as longer, so it is obvious and bright. Fluorescence is widely used on traffic sign when combined with reflection material, which improves the recognition of traffic sign in bad environment. Meanwhile, the fluorescent road marking greatly reduces the occurrence of traffic accidents.
Figure 1. The road marking
Categories
According to the materials, common road markings are mainly divided into the following categories:[1]
- Long Persistent Luminescence Materials
Long persistent luminophores materials have very long afterglow (in general: seconds to even days) and follow thermally, optically or mechanically induced luminescent mechanism. The mechanism of long persistent luminescent materials is different from that of common fluorescent or phosphorescent substances. The long persistent luminescence mechanism is that energy traps (electrons or holes) of a material which are filled after irradiation and the absorbed energy is gradually degraded, finally emitted in the form of light.
Figure 2. Schematic of different luminescence mechanisms: Simplified model of the mechanisms of (a) the long persistent luminescence and (b) fluorescence and phosphorescence.
Inspired by recent developments in nanotechnology, our approach to special long afterglow luminophore pigment functionalization for enhanced quality of road marking. The functionalized modern pigments have advantages as follows:
a) Enhanced weatherability, durability and robustness of the marking pigment, which results in enhanced quality of the marking pigment.
b) Enhanced dispersion capacity due to the generation of a pigment binding agent. Saving of material.
c) Enhanced light output of the long persistent luminescent marking due to higher percentage usage of the luminescent pigment.
- Inorganic-Organic Hybrid Polymers
Inorganic-organic hybrid materials are that nano-composites with intimately mixed organic and inorganic components. The hybrid materials categorized into two distinct classes according to their intermolecular contacts face: weakly bonded organic and inorganic components (by supramolecular interactions: hydrogen bonding, Van der Waals contacts or electrostatic forces) and strong chemical bonds (covalent, no-covalent or Lewis acid-base bonds). In Figure 3 schematic illustration of inorganic-organic hybrid materials is shown referring to inorganic-organic hybrid materials with pigments or particles embedded.
Figure 3. Schematic illustration of inorganic-organic hybrid materials with pigments or particles embedded.
What Can Alfa Chemistry Do?
Alfa Chemistry's technical R&D team has focused on the preparation and application of fluorescent materials for many years, which has established long-term cooperative relationships with many well-known enterprises and research institutions. We have conducted research on various problems encountered by road marking, which can select the appropriate solution according to the customer's experimental purpose. The related technologies of road marking we provide are as follows:
- We can provide the technology of spraying, including dip-coating, spin-coating, capillary or meniscus coating, flow coating and roll coating.
- We can customize relevant solutions to meet customer needs in order to help researchers solve the problems.
Reference
- Arras J.; et al. The world needs new colors: cutting edge mobility focusing on long persistent luminescence materials. ChemPhotoChem, 2018, 2(2): 55-66.
