Hydrochloric acid (hcl)

Clean
sheep’s wool was obtained from
Wingham Wool Work. Sunflower oil was obtained from Tesco and used
as the DP for the primary emulsion. Urea ≥ 98%, sodium metabisulfite
≥ 99%, tris(hydromethyl)aminomethane ≥ 99.8%, sodium
dodecyl sulfate (SDS) ≥ 95%, hydrochloric acid (HCl, 35%),
and sodium hydroxide (NaOH, 98%) were purchased from Fisher Scientific,
UK. HCl and NaOH were diluted to 0.1 M as stock solution for pH adjustments;
low-molecular-weight chitosan, acetic acid ≥ 99%, fluorescein
isothiocyanate (FITC) ≥ 90%, methanol ≥ 99.9%, nile
red ≥ 98%, hydrochloric acid 32%, and GTA solution grade II
25 wt % in H₂O were obtained from Sigma-Aldrich UK and
used without further purification.

Polyaniline was prepared by oxidation
of aniline hydrochloride (10% in water at pH about 1) with the chemical
method described elsewhere, modified in our laboratory.
The
polymeric material (polyaniline) was characterized with physical and
chemical methods: FTIR, EPR, elemental analysis, and electrical conductivity
measurements, giving results similar to the values measured for materials
previously prepared in our laboratory.^{21 (link),22 (link),45 (link)}Chemicals and solvents:
Hydrochloric
acid (HCl) (Stanlab, pure p.a.)—600 mL of 1
M solution prepared from concentrated hydrochloric acid (36%)—50
mL of 36% HCl dissolved in 550 mL of H₂O.
Aniline
hydrochloride (C₆H₈NCl) (Fisher Scientific,
pure p.a.)—6.9 g of aniline hydrochloride dissolved in 300
mL of 1 M hydrochloric acid.
Ammonium persulfate [(NH₄)₂S₂O₈] (Chempur, pure p.a.)—11.4
g of ammonium persulfate
was dissolved in 200 mL of 1 M hydrochloric acid.
Ammonium hydroxide
(NH₄OH) solution 25% (POCh, pure
p.a.)—500 mL of 1 M solution prepared from concentrated ammonium
hydroxide (25%)—37 mL of 25% ammonium hydroxide dissolved in
463 mL of H₂O.
Chloroform (CHCl₃) (Chempur,
pure p.a.)—75 mL.
p-Toluenesulfonic
acid (CH₃C₆H₄SO₃H) (Aldrich,
p.a.)—1.4 g of p-toluenesulfonic acid was
dissolved in 75 mL of Chloroform.