Study of Faujasite zeolite as a modified delivery carrier for isoniazid

The adsorption of isoniazid in the Faujasite zeolite channels has been studied. For that, the influence of the pH from the solution media in the adsorption process was verified to enable higher amount of isoniazid retained. With the information of the best pH and the equilibrium time obtained with the kinetic study, an isotherm was constructed and the hybrid material obtained with the plateau concentration equilibrium was characterized with several techniques. Molecular modeling calculations were also performed for a better understanding of the adsorption process and how the interaction between zeolite and isoniazid occurs. The geometrical disposition of the drug molecules into the zeolite channels, the saturation levels, the different isoniazid protonation states with respect to the pH media and the interaction energy between the zeolite surface and the isoniazid molecule was studied. Finally, a drug release study was made to verify if the Faujasite-Y zeolite could change the isoniazid release in acid and phosphate buffer media. The results show that the Faujasite-Y has the possibility to work as carrier for isoniazid, where the adsorption process is more effective in media at pH 3, result confirmed by the molecular modeling. The isoniazid release essay showed that the hybrid material does not change the drug release profile, provides more stability in acid media, indicating that the zeolite can be used as carrier for isoniazid, and improve the medicine formulations on antituberculosis treatment.This research was financed by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), the Spanish Project FIS-2016-77692-C2-2-P and the Andalusian Project RNM-1897. Thanks to the Instituto Andaluz de Ciencias de la Tierra (IACT), to the pharmacy PhD program from University of Granada, Spain and to the materials science and engineering PhD program from Universidade Federal do Rio Grande do Norte (UFRN), Brazil

Incorporation of Brazilian diatomite in the synthesis of an MFI zeolite

The need for greener procedures is a fact to reduce residues, to decrease industrial costs, and to accomplish the environmental agreements. In an attempt to address this question, we propose the addition of a natural resource, Brazilian diatomite, to an MFI zeolite traditional synthesis. We have characterized the resulting product with different techniques, such as X-ray diffraction, microscopy, and gas sorption, and, afterwards, we evaluate the greenness of the process by the Green Star method. The results were promising: We obtained the desired topology in the form of small crystallites aggregated and a pore diameter of 0.8 nm. In conclusion, the product has the necessary characteristics for an adsorption or catalytic future tests and escalation to industrial production.P.V. thanks PPGCEM (UFRN) and CAPES for the predoctoral fellowship (2013–2017, “This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior—Brasil (CAPES)—Finance Code 001”). C.W.L. acknowledges CAPES for a predoctoral fellowship, Science without Frontiers—Process no. 13191/13-6

Carbon foams from sucrose employing different metallic nitrates as blowing agents: Application in CO2 capture

Carbon foams were prepared employing sucrose as the carbon source. The porosity of the materials as well as the morphology was controlled using different metallic nitrates during the synthesis, such as aluminum (obtaining EsAl foam), iron (obtaining EsFe foam) and silver (obtaining EsAg foam) nitrate. The samples have interconnecting pores with a turbostratic structure, where the EsFe foam shows a more ordered structure. The addition of the chemical agents promotes improvements in the porosity of the foams, highlighting those obtained with the aluminum nitrate nonahydrate - EsAl (98%) and iron nitrate nonahydrate - EsFe (90%), as well as a greater control of pore growth avoiding collapse. All carbon foams presented a microporous nature, but EsFe foam also present mesoporosity (with pore sizes between 2.2 to 3.5 nm). The high specific surface area values for EsAl and EsFe carbons (600 and 380 m2/g) were attributed to in situ activation during carbonization of the foams. All carbon foams present ultramicropores with pore sizes less than 0.6 nm. The synthesized carbon foams have interesting CO2 adsorption capacities, mainly the EsAl foam that reach CO2 adsorption capacities (at 1000 kPa) of 4 and 4.4 mmol/g at 50 °C and at 35 °C, respectively. These capacities of the carbon foams obtained were similar to those reported in the bibliography for other carbon materials, shows their great potential as CO2 adsorbents. The isosteric heat of CO2 adsorption show that the CO2 capture with the carbon foams synthesized is associated with a physisorption process.Fil: de Araújo, Maria José Gomes. Universidade Federal do Rio Grande do Norte; BrasilFil: Villarroel Rocha, Jhonny. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; ArgentinaFil: de Souza, Vanessa Castro. Universidade Federal do Rio Grande do Norte; BrasilFil: Sapag, Manuel Karim. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; ArgentinaFil: Pergher, S.B.C.. Universidade Federal do Rio Grande do Norte; Brasi