Probing cellulose wettability by electron paramagnetic resonance

• Autorzy: Ionita G. , Ghica C. , Ionita P.
• Języki publikacji: EN

Abstrakty

EN

Carboxymethyl-cellulose has been labelled with a stable free radical by reaction with 4-aminotempo in the presence of a coupling agent (EEDQ). The spin-labelled cellulose is highly stable, no leaking being noticed after months at room temperature. EPR spectroscopy was used as a main tool to study the wettability of such a material. The EPR spectrum of the dry spin-labelled cellulose shows the expected anisotropy, while addition of several solvents (acetone, ethyl acetate, DCM, methanol, toluene, PEG 200) induces the splitting of the spectrum into a two component system. Thus, the EPR spectrum is composed of a mobile component superimposed onto an immobilized one. Addition of water leads to a monocomponent isotropic spectrum. These data clearly indicate the presence of two types of sites to which the spin-label is attached. Variable temperature EPR spectra showed that an increase of temperature results in an increase in the mobility of the spin-label. Deposition of plain or spin-labelled gold nanoparticles on the cellulose fibres also affects the structure of the polymeric chain, as seen by changes in the EPR spectra.

Słowa kluczowe

EN

cellulose; EPR; radical; tempo; spin label

• Wydawca: De Gruyter
• Czasopismo: Materials Science Poland
• Rocznik: 2007
• Tom: Vol. 25, No. 4
• Strony: 1011--1017
• Opis fizyczny: Bibliogr. 12 poz., rys., tab.

Twórcy

autor

Ionita G.

• Institute of Physical Chemistry, Spl. Independentei 202, Bucharest 060021, Romania

autor

Ghica C.

• National Institute for Materials Physics, PO Box MG-7, 077125 Bucharest-Magurele, Romania

autor

Ionita P.

• Institute of Physical Chemistry, Spl. Independentei 202, Bucharest 060021, Romania

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