- Tytuł:
- Hydration of Hydroxypropylmethyl Cellulose: Effects of pH and Molecular Mass
- Autorzy:
-
Tritt-Goc, J.
Kowalczuk, J.
Piślewski, N. - Powiązania:
- https://bibliotekanauki.pl/articles/2043541.pdf
- Data publikacji:
- 2005-07
- Wydawca:
- Polska Akademia Nauk. Instytut Fizyki PAN
- Tematy:
-
82.70.Gg
76.60.Pc - Opis:
- Magnetic resonance imaging was used to study the diffusion of a water solution of hydrochloric acid (HCl) and sodium hydrochloride (NaOH) into hydroxypropylmethyl cellulose matrices. Polymer in the form of a cylinder was hydrated in a water solvent of pH = 2, 7, and 12 at 37ºC and monitored at equal intervals with a 300 MHz Bruker AVANCE. The spatially resolved spin-spin relaxations times and spin densities, along with a change in the dimension of the glass core of the polymer were determined for hydroxypropylmethyl cellulose tablets as a function of hydration times. The data showed the effects of the pH solvent and of the molecular mass of the polymer on the swelling process, spin-spin relaxation time, and diffusion of solvent molecules into hydroxypropylmethyl cellulose matrices. The time dependence of the diffusion front, effective T$\text{}_{2}$, and proton-density ρ analysis clearly indicate a case II diffusion mechanism in the system composed of a water solution of hydrochloric acid (pH = 2) and hydroxypropylmethyl cellulose, whereas in the case of water solutions with pH = 7 and 12 the anomalous and case I diffusion are observed, respectively.
- Źródło:
-
Acta Physica Polonica A; 2005, 108, 1; 197-205
0587-4246
1898-794X - Pojawia się w:
- Acta Physica Polonica A
- Dostawca treści:
- Biblioteka Nauki
Artykuł