Iron 3 chloride

L-tryptophan (98%), decanoyl chloride (98%), sodium hydroxide (97%), sodium bicarbonate (97%), 3-aminopropyl trimethoxysilane (97%), tetraethyl orthosilicate (98%), butyric acid (99%), cetyltrimethylammonium bromide (99%), and dichloromethane (99.8%) were purchased from Sigma-Aldrich (St. Louis, MO, USA). Tetrahydrofuran (TFH, 99.5%), hydrochloric acid (35% w/w), oleic acid (99%), palmitic acid (99%), citric acid (99%), ammonia solution (32% w/w), iron (III) chloride (97%), iron (II) chloride tetrahydrate (99%), and sodium chloride (99.5%) were supplied by Scharlab (Barcelona, Spain).

Bleached eucalyptus kraft
pulp, unrefined (15 °SR), was provided by Ence (Navia, Spain).
2,2,6,6-Tetramethylpiperidine-1-oxy radical (TEMPO), NaBr, NaOH, NaClO
(15%), copper(II) ethylenediamine, and DTZ (≥98%) were purchased
from Sigma-Aldrich (Schnelldorf, Germany). Glacial acetic acid was
purchased from Scharlab (Sentmenat, Barcelona, Spain). All organic
solvents (reagent grade) were received from Thermo Fisher Scientific
(Loughborough, U.K.). Preliminary results indicated that amylene-stabilized
chloroform is preferred over ethanol-stabilized chloroform.
Distilled water was used for nanocellulose production, but metal
salts were dissolved in Milli-Q water. These metal salts were lead(II)
nitrate, lead(II) chloride, cadmium(II) nitrate, cadmium(II) chloride,
copper(II) chloride, nickel(II) chloride, chromium(III) chloride,
chromium(III) nitrate, and magnesium chloride from Panreac Applichem
(Castellar del Vallès, Barcelona, Spain); potassium nitrate,
iron(III) chloride, and manganese(II) chloride from Scharlab; and
mercury(II) nitrate 1-hydrate, mercury(II) chloride, silver nitrate,
and zinc chloride from Sigma-Aldrich.