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® 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, 29Si 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.