Carbon nanodot–ORMOSIL fluorescent paint and films

Abstract

Room temperature synthesis of micelle-protected highly fluorescent carbon nanodots (CNDs) and fabrication of scratch-resistant CND–ORMOSIL films and paint.

Carbon Dots from a Single Source Exhibiting Tunable Luminescent Colors through the Modification of Surface Functional Groups in ORMOSIL Films

“…It is noteworthy here that our main objective is to fabricate stable multicolor emitting fluorescent films through the modification of surface functionalities of CDs via pH tuning in ORMOSIL sol and followed by film fabrication. For embedment of CDs with retention of its chromophoric structure, we have selected ORMOSIL sol as our organic–inorganic host matrix as this sol have been widely explored as a hard coating as well as fluorescent nanoparticle-embedded transparent films. , First, the pristine green-color-emitting purified CDs (image shown in Figure S1b, Supporting Information) were mixed with ORMOSIL sol in proper ratios. Because the ORMOSIL sol has been prepared by acid hydrolysis method, the initial pH of the sol remains mildly acidic (pH ∼5) after mixing the solution of CDs.…”

“…2 film was measured by a UV power puck (S/N-8000; EIT), and the value was 7 mW cm −2 . For this purpose, film was kept 2 cm apart from lamps of 8 W. 30 Refractive index of CD-ORMOSIL film was measured by spectroscopic ellipsometer (J. A. Woollam).…”

“…However, the development of hard, transparent fluorescent films using organic–inorganic silica matrices remains relatively unexplored. In this regard, it has been established that organically modified silica known as ORMOSIL ,− can be the best choice for stabilization of photoluminescent QDs, CDs, and composite , nanoparticles to obtain hard, transparent, inexpensive fluorescent films on glass and plastic substrates for optical applications. Actually, ORMOSIL matrix due to its inherent inorganic–organic hybrid functional properties stabilizes the CDs from agglomeration both in the sol as well as in the film.…”

“…The purified green-emitting CDs were then incorporated in ORMOSIL sol to obtain orange-, yellow-, and green-emitting sols by simple pH tuning. Afterward, these stable triluminous sols were utilized to prepare tricolor luminescent films on glass substrates with stable PL and high QYs (detailed description given in Figure ) by dip-coating technique, followed by curing. ,,, It is noteworthy here that the same CD-ORMOSIL sol could produce tricolor emission (orange → yellow → green) with increasing pH values, signifying the changes in surface functional groups associated with CDs producing diverse surface states. To the best of our knowledge, this is the first report of pH-responsive tricolor emissive CD-ORMOSIL sols that were intelligently preserved as hard and transparent films without sacrificing their inherent PL characteristics.…”

Eco-friendly carbon-nanodot-based fluorescent paints for advanced photocatalytic systems

“…The liquid carbon-rich polymers are scalable in an economic point of view. Of particular interest is the recent finding that viscous-fluorescent CDs can be mixed with various materials to become strongly fluorescent in UV- and visible-spectral regions192021.…”