Tri-ureasil gel as a multifunctional organic-inorganic hybrid matrix

We report on a novel transparent, flexible, rubbery, and insoluble tri-ureasil organic-inorganic hybrid material with multifunctional characteristics and potential application in drug delivery, water purification, and photochromic materials. We obtained the tri-ureasil gels by the one-pot sol-gel route using 3-isocyanatopropyltriethoxysilane and glyceryl poly(oxypropylene) triamine of molecular weight 5000 g mol(-1) (Jeffamine (R) T5000). This approach generated a silica backbone covalently connected with poly(oxyalkylene) chains PPO(OCH-CH3CH2)(n) through urea bridges. We characterized the obtained materials by DSC, swelling tests, XRD, Si-29 NMR, and small-angle X-ray scattering (SAXS). The results attested that the tri-ureasil hybrids are potentially applicable as photochromic devices, drug delivery systems, and adsorbents of pollutants from contaminated waters.