suspension was stored at 4 C overnight. Finally, a transparent colloidal
solution of TiO2 nanoparticles was formed. Neither an isolation
of TiO2 from the colloid nor further calcination was performed.
For modification of TiO2 surface three organic compounds were
chosen (Fig. 1). Sodium 1,2-dihydroxybenzene-3,5-disulphonate
(tiron; Trn) and ascorbic acid (Asc) are simple, inexpensive single
ring compounds. They are water soluble, their anionic forms prevail
at neutral pH. Rutin (Rtn), a-L-rhamnopyranosyl-(1 ? 6))-bD-glucopyranose,
is a natural flavonoid found in many plants
(e.g., buckwheat) carrying sugar moiety, responsible for its hydrophilicity
and solubility in water.
All modified TiO2 nanomaterials in the form of solutions and
coatings were prepared by a direct TiO2 surface modification by organic
compounds containing either catechol (tiron and rutin) or
enodiol functional group (ascorbic acid). Surface modification occurred
spontaneously after mixing the aqueous solution containing
an excess of organic compound with the colloidal solution of TiO2
(molar ratio of organic compound to TiO2 was 1:1). Directly after
mixing the color change and precipitation occurred in the case of
tiron and rutin. The precipitate was dissolved after neutralization
with NaOH solution to pH 7. The solution was placed in a dialysis
tube (Sigma, cut-off 14 kDa) and dialyzed against water in order to
remove isopropyl alcohol and the unbound modifier.
suspension was stored at 4 C overnight. Finally, a transparent colloidalsolution of TiO2 nanoparticles was formed. Neither an isolationof TiO2 from the colloid nor further calcination was performed.For modification of TiO2 surface three organic compounds werechosen (Fig. 1). Sodium 1,2-dihydroxybenzene-3,5-disulphonate(tiron; Trn) and ascorbic acid (Asc) are simple, inexpensive singlering compounds. They are water soluble, their anionic forms prevailat neutral pH. Rutin (Rtn), a-L-rhamnopyranosyl-(1 ? 6))-bD-glucopyranose,is a natural flavonoid found in many plants(e.g., buckwheat) carrying sugar moiety, responsible for its hydrophilicityand solubility in water.All modified TiO2 nanomaterials in the form of solutions andcoatings were prepared by a direct TiO2 surface modification by organiccompounds containing either catechol (tiron and rutin) orenodiol functional group (ascorbic acid). Surface modification occurredspontaneously after mixing the aqueous solution containingan excess of organic compound with the colloidal solution of TiO2(molar ratio of organic compound to TiO2 was 1:1). Directly aftermixing the color change and precipitation occurred in the case oftiron and rutin. The precipitate was dissolved after neutralizationwith NaOH solution to pH 7. The solution was placed in a dialysistube (Sigma, cut-off 14 kDa) and dialyzed against water in order toremove isopropyl alcohol and the unbound modifier.
การแปล กรุณารอสักครู่..