268 research outputs found
Copolymer-induced stabilizing effect of highly swollen hexagonal mesophases
We show quantitatively that tiny amounts of copolymer that decorate a
oil/water interfaces can greatly enhance the stability of swollen surfactant
hexagonal phases, comprising oil tubes regularly arranged in a water matrix.
Such soft composite materials, whose both radius of the tubes and water channel
between the tubes can be controlled independently over large ranges, offer a
potential interest for the synthesis of mesoporous materials
Introduction to celebrating Latin American talent in chemistry
In celebration of the excellence and breadth of Latin American research achievements across the chemical sciences, we are delighted to present an introduction to the themed collection, Celebrating Latin American talent in chemistry. [Image: see text
Ordered mesoporous silica prepared by quiescent interfacial growth method - effects of reaction chemistry
Thin films of cubic mesoporous aluminophosphates modified by silicon and manganese
Mesoporous aluminophosphate thin films and xerogels with ordered three-dimensional pore arrangement, modified by silicon or silicon and manganese, were synthesized. Aluminophosphate reaction mixtures were templated with non ionic polymer surfactant Pluronic F127 and deposited as thin layers of precursor solution on Petri dishes for xerogels and on glass substrates for thin films. Surfactant removal was investigated by thermal analysis. Small Angle X-ray Scattering measurements showed that calcined silicoaluminophosphate (SAPO) and manganese silicoaluminophosphate (MnSAPO) thin films have highly ordered mesostructures, which remain stable up to at least 400°C. The mesostructures exhibit cubic symmetry described by an Im3̄m space group. Cubic mesostructure was confirmed also by TEM, SEM and AFM microscopy. Incorporation of silicon and manganese into the aluminophosphate framework was studied by solid-state NMR and X-ray absorption spectroscopy. Silicon-rich domains were detected in calcined SAPO and MnSAPO xerogels and in MnSAPO thin films. The observation of Si(OSi)3(OAl) framework units at the border of such domains suggests that acid sites might be included within silicoaluminophosphate walls. Mn3+ and Mn2+ cations are present in the MnSAPO frameworks of calcined xerogels and thin films in the molar ratio of 40%/60%. Manganese cations are coordinated to four oxygen atoms, suggesting that they are incorporated within the framework and that they can act as framework redox sites.Fil: Cecowski, Sasa. National Institute Of Chemistry; EsloveniaFil: Tusar, Natasa Novak. National Institute Of Chemistry; EsloveniaFil: Rangus, Mojca. National Institute Of Chemistry; EsloveniaFil: Mali, Gregor. National Institute Of Chemistry; EsloveniaFil: Soler Illia, Galo Juan de Avila Arturo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; ArgentinaFil: Kaucic, Venceslav. National Institute Of Chemistry; Esloveni
Mesoporous Aminopropyl-Functionalized Hybrid Thin Films with Modulable Surface and Environment-Responsive Behavior
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