Speaker
Mr
ElSayed Hegazy
(Atomic Energy Authority, Egypt)
Description
El-Sayed A. Hegazy , Hassan A. Abd El-Rehim
National Center for Radiation Research and Technology, Egyptian Atomic Energy Authority, P.O.Box 29, Nasr City, Cairo 11371, Egypt.
Abstract:
The effect of ionizing radiations on the cross-linking and degradation
of some natural polymers such as CMC-Na, chitosan, carrageenan,
alginates and starch was investigated. Trials were made to control
and reduce the irradiation dose required for the CMC-Na degradation by
the addition of some additives and controlling the irradiation
conditions. The possibility to cross-link CMC-Na/PAAm and starch/PAAm
blends using electron beam irradiation to obtain good adsorbent
materials of unique properties for possible practical uses were also
investigated. The end product of irradiated natural products such as
carboxy-methylcellulose, chitosan and Na-alginate may be used as food
additive or benefited in agricultural purposes. From an economic point
of view these doses are not accepted, it was significantly reduced by
the addition of APS, KPS and H$_2$O$_2$. The addition of such additives to
chitosan or Na-alginate during irradiation process accelerates their
degradation. Degraded Na-alginate and chitosan could be used as
growth promoter for plants in agriculture purposes. The growth and
other responses of Zea maze and bean plants that treated with
irradiated Na-alginate or chitosan of different Mw’s were
investigated. The test field results showed that the treatment of the
zea plant with irradiated Na-alginate or chitosan enhanced the plant
growth and increases its productivity.
Chemically cross-linked, pH-sensitive PVP/PAAc hydrogel nanoparticles
were successfully prepared in a high yield via
$\gamma$-radiation-induced polymerization of acrylic acid in aqueous
solution of poly(vinylpyrrolidone) (PVP) as a template polymer. The
particle sizes of the PVP/PAAc nanogels at different pH values were
evaluated using dynamic light scattering (DLS) and the morphology was
assessed using atomic force microscopy (AFM) and transmission electron
microscopy (TEM). Smaller and more stable nanogel particles can be
produced by irradiating a feed solution of $50$–$75$ mol% AAc and
using PVP of high molecular weight. Factors affecting size and
encapsulation efficiency were optimized to obtain nanogel sufficient
to entrap drug efficiently. The use of PVP/PAAc nanogels prepared at
different compositions and irradiation doses was evaluated for dry eye
syndrome application.
| Country/Organization invited to participate | Egypt |
|---|
Primary author
Mr
ElSayed Hegazy
(Atomic Energy Authority, Egypt)
