Converting Waste Papers to Fluorescent Carbon Dots in the Recycling Process without Loss of Ionic Liquids and Bioimaging Applications

Abstract

Recycling is a fascinating topic in academia due to the environmental and economic benefits in industries. In this paper, we report on the method to recycle cellulose waste papers using a green (eco-friendly) approach based on ionic liquids (ILs) where the regenerated cellulose was converted to carbon dots (CDs). The addition of waste papers to the IL, 1-allyl-3-methylimidazolium chloride ([Amim]­[Cl]), disrupted the chemical arrangement of cellulose and completely dissolved the waste paper under microwave irradiation. Subsequent cellulose regeneration by an additional antisolvent, absolute ethanol, was carried out to recover IL and obtain cellulosic materials’ units from waste papers. Furthermore, we report a practical strategy to fabricate CDs under microwave-assisted irradiation. The CDs made by the regenerated cellulose (RC-CDs) were characterized by using analytical and spectroscopic techniques, such as transmission electron microscopy (TEM) and X-ray diffraction (XRD). Finally, we confirmed that RC-CDs exhibited low cytotoxicity, which suggests RC-CDs acts as a promising fluorescent probe for bioimaging.

Miscanthus grass-derived carbon dots to selectively detect Fe3+ ions

“…Aer reaching the critical supersaturation concentration, a nuclear burst of the aromatic clusters takes place to form the MCDs. 27…”

“…Paper wastes were also used to synthesize CDs via microwave-assisted pyrolysis, using ionic liquid as solvent. 27 However, this work features the novel use of an agricultural residue.…”

A Facile Synthesis of Green‐Blue Carbon Dots from Artocarpus lakoocha Seeds and Their Application for the Detection of Iron (III) in Biological Fluids and Cellular Imaging

“…The UV‐vis absorption spectrum of GB‐CDs showed two peaks at 276 nm and 334 nm, which were due to π‐π* of carbon‐carbon double bond and n‐π* of the carbonyl compound ( Figure A ) . The as‐prepared GB‐CDs exhibited excitation dependent fluorescent emission spectra on changing the excitation wavelength from 320 nm to 410 nm.…”

Chemical versus physical grafting of photoluminescent amino-functional carbon dots onto transparent nematic nanocellulose gels and aerogels

“…While top-down approaches rely on laser ablation, arc discharge or electrochemical synthesis, bottom-up strategies employ methods like thermal combustion, hydrothermal or microwave synthesis. Precursor compounds for the latter can be low-molecular organic compounds (Lim et al 2015) or natural source materials, such as lignocellulose (Jeong et al 2018;Rodríguez-Padrón et al 2018), starch (Duarah and Karak 2017) or lemon juice. Carbon dots and semiconductor quantum dots have been demonstrated to share many similarities with regard to single-digit nano size or optical properties.…”