M toluidine

Wool fabrics (Yünsa Wool Industry and Trade Co., Tekirdağ, Turkey) were washed before use in 4g/L of aqueous ECE (B) reference detergent (James Heal) solution at 40 °C for 1h. The fabrics were then dried in a vacuum oven at 50 °C until constant weight. The chemicals that were written in the process sequence, including NaHS.xH₂O (90%), urea (99.5%), thiourea (99%), thioglycolic acid (TGA) (80%), NaOH (98%), HCl (37%), ethyl alcohol (96.5%), m-toluidine (99%), m-toluidine sulphate (99%), ammonium persulfate (APS) (98%), ((NH₄)₂S₂O₈), H₂SO₄ (96.5%), and methanol (99.8%) were obtained from Sigma-Aldrich and used without further purification.

The synthesis of CD_3011, CDN19, CDF19 CDs was generally similar to the procedure for the synthesis of F-O-N-containing CDs described in [13 (link)]. Briefly, to prepare CD_3011, CDN19 and CDF19, we took a three Pyrex glass bottles, and in every bottle 10 g of urea (167 mmol, ACS reagent, 99.0–100.5%, Sigma-Aldrich), 16 g of anhydrous citric acid (83 mmol, ACS reagent, ≥ 99.5%), and in second and third case, 21 mmol of corresponding amine (3.38 g of 3-(Trifluoromethyl)aniline, ≥ 99%, Sigma-Aldrich, or 2.25 g of m-Toluidine, 99%, Sigma-Aldrich) were placed (Table 1). Mixtures were homogenized and placed in the oven at 135 °C for 3 h. During this stage, synthesis ammonia and other gases and vapors were evolved. Then, temperature was increased to 165 °C for 2 h. Obtained products (as shining brittle solidified melt with numerous bubbles) were dissolved in 135 mL of solution consisting of water: ethanol: ammonia = 100: 10: 25, the residues were filtered off. Then, approx. 30 mL of concentrated hydrochloric acid was added and left overnight. Precipitate was dried on air at 120 °C.
The structure of CD_3011, CDN19, CDF19 was discovered by thermogravimetry and differential scanning calorimetry (NETZSCH STA 449 F3 Jupiter®—Thermal Analysis System, Germany).