Browsing by Author "Martin-Trasanco, Rudy"
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- ItemA new porous organic polymer containing Troger's base units: Evaluation of the catalytic activity in Knoevenagel condensation reaction(2021) Rodriguez-Gonzalez, Fidel E.; Niebla, Vladimir; Velazquez-Tundidor, M. V.; Tagle, Luis H.; Martin-Trasanco, Rudy; Coll, Deysma; Ortiz, Pablo A.; Escalona, Nestor; Perez, Edwin; Jessop, Ignacio A.; Terraza, Claudio A.; Tundidor-Camba, AlainThe classic Tro center dot ger's base polymerization of a diamine and dimethoxymethane with trifluoroacetic acid as catalyst generated a Tro center dot ger's base-type polymer (TBP), which exhibited the absolute insolubility in a variety of organic solvents because of its highly aggregated model. A new porous organic polymer was obtained by a simple Tro center dot ger's base polymerization reaction between a diamine and formaldehyde in the form of acetal in the presence of trifluoroacetic acid as catalyst. Tro center dot ger's base-type polymer (TBP) resulted insoluble in a wide range of organic solvents due to its rigid and aromatic structure. TBP was characterized spectroscopically (FT-IR), thermally and morphologically. As result, a thermostable and amorphous polymer bearing pores ranging between 50 and 300 nm and macro-voids of up to 12 mu m was obtained. Due to the insolubility of the TBP, it was tested as a metal-free heterogeneous catalyst in the Knoevenagel condensation reaction, showing a high efficiency. For this, the optimal catalyst load, reaction time and reuse of the catalyst were studied using benzaldehyde and malononitrile as substrates. Furthermore, aldehydes with variable chain sizes and ethyl cyanoacetate replacing malononitrile were tested as substrate with a high percent of conversion (97-99%).
- ItemIn-Situ Preparation of CdTe Quantum Dots Capped with beta-Cyclodextrin-Epichlorohydrin Polymer : Polymer Influence on the Nanocrystal's Optical Properties(2018) Martin-Trasanco, Rudy; Esparza-Ponce, Hilda E.; Ortiz Rodríguez, Pedro David; Oyarzun, Diego P.; Zuniga, Cesar; Montero-Cabrera, Maria E.; Tundidor Camba, Alain; Pizarro, Guadalupe del C.; Arratia-Perez, Ramiro
- ItemPolycaprolactone and poly-β-cyclodextrin polymer blend: a Biopolymers composite film for drug release(2022) Antonella Sepulveda, Francesca; Sanchez, Julio; Oyarzun, Diego P.; Rodriguez-Gonzalez, Fidel E.; Tundidor-Camba, Alain; Garcia-Herrera, Claudio; Zapata, Paula A.; Pizarro, Guadalupe del C.; Martin-Trasanco, RudyNowadays, biomedical films containing drug carriers are preferred over conventional ones, since the protection of the injury and the therapy is joined within a single device. In the current work, we prepared polycaprolactone (PCL) composite films with beta-cyclodextrin (beta CD) or its epichlorohydrin crosslinked polymer (beta CDP) as ibuprofen (Ibu) drug carrier. The composite films were prepared at different PCL/additive ratios (2, 5, 10 and 20 wt%). ATR-FTIR spectroscopy and water contact angle (WCA) measurements indicated a scarce presence of the additives on the surface. Cross-section scanning electron micrographs showed the presence of aggregates corresponding to beta CD and beta CDP in the inner regions of the films. The incorporation of beta CD and beta CDP into the PCL films did not affect their thermal properties as was determined from differential scanning calorimetry (DSC). PCL-films with 10 wt% of the inclusion complexes Ibu@beta CD and Ibu@beta CDP were prepared and the release studies were performed. At pH = 7.2, PCL-Ibu@beta CDP composite film released 55% of Ibu within the first six hours; eight times the amount released by PCL-Ibu@beta CD within the same time interval. A plausible mechanism for ibuprofen release is discussed based on the cross-section SEM micrographs of composite films.
- ItemPVDF Composite Membranes with Hydrophobically-Capped CuONPs for Direct-Contact Membrane Distillation(2021) Saldias, Cesar; Terraza, Claudio A.; Leiva, Angel; Koschikowski, Joachim; Winter, Daniel; Tundidor-Camba, Alain; Martin-Trasanco, RudyWater scarcity is an imminent problem that humanity is beginning to attempt to solve. Among the several technologies that have been developed to mitigate water scarcity, membrane distillation is of particular note. In the present work, CuO nanoparticles capped with 1-octanethiol (CuONPs@CH) or 1H,1H,2H,2H-perfluorodecanethiol (CuONPs@CF) are prepared. The nanoparticles are characterized by FT-IR and TGA methods. Two weight losses are observed in both cases, with the decomposition of the organic fragments beginning at 158 degrees C and 230 degrees C for CuONPs@CF and CuONPs@CH, respectively. Flat sheet PVDF composite membranes containing nanoparticles are prepared by the casting solution method using nanoparticle concentrations that ranged between 2-20% with a non-woven polyester fabric as support. The obtained membranes showed a thickness of 240 +/- 40 mu m. According to water contact angle (87 degrees for CuONPs@CH and 95 degrees for CuONPs@CF, both at 10% w.t) and roughness (12 pixel for CuONPs@CH and 14 pixels for CuONPs@CF, both at 10% w.t) determinations, the hydrophobicity of membranes changed due to a decrease in surface energy, while, for naked CuONPs, the roughness factor represents the main role. Membranes prepared with capped nanoparticles showed similar porosity (60-64%). SEM micrographs show asymmetric porous membranes with a 200-nm surface pore diameter. The largest finger-like pores in the membranes prepared with CuONPs, CuONPs@CH and CuONPs@CF had values of 63 +/- 10 mu m, 32 +/- 8 mu m, and 45 +/- 10 mu m, respectively. These membranes were submitted to a direct contact membrane distillation module and flux values of 1.8, 2.7, and 3.9 kg(m(2)center dot h)(-1) at Delta T = 30 degrees C were obtained for the CuONPs, CuONPs@CH, and CuONPs@CF, respectively. The membranes showed 100% salt rejection during the testing time (240 min).
- ItemSpraying Fluorinated Silicon Oxide Nanoparticles on CuONPs@CF-PVDF Membrane: A Simple Method to Achieve Superhydrophobic Surfaces and High Flux in Direct Contact Membrane Distillation(2022) Lenac, Zivka; Saldias, Cesar; Terraza, Claudio A.; Leiva, Angel; Koschikowski, Joachim; Winter, Daniel; Tundidor-Camba, Alain; Martin-Trasanco, RudyDesalinization of seawater can be achieved by membrane distillation techniques (MD). In MD, the membranes should be resistant to fouling, robust for extended operating time, and preferably provide a superhydrophobic surface. In this work, we report the preparation and characterization of a robust and superhydrophobic polyvinylidene fluoride membrane containing fluoroalkyl-capped CuONPs (CuONPs@CF) in the inner and fluorinated capped silicon oxide nanoparticles (SiO(2)NPs@CF) on its surface. SiO(2)NPs@CF with a mean diameter of 225 +/- 20 nm were prepared by the sol method using 1H,1H,2H,2H-perfluorodecyltriethoxysilane as a capping agent. Surface modification of the membrane was carried out by spraying SiO(2)NPs@CF (5% wt.) dispersed in a mixture of dimethyl formamide (DMF) and ethanol (EtOH) at different DMF/EtOH % v/v ratios (0, 5, 10, 20, and 50). While ethanol dispersed the nanoparticles in the spraying solution, DMF dissolved the PVDF on the surface and retained the sprayed nanoparticles. According to SEM micrographs and water contact angle measurements, the best results were achieved by depositing the nanoparticles at 10% v/v of DMF/EtOH. Under these conditions, a SiO(2)NPs covered surface was observed with a water contact angle of 168.5 degrees. The water contact angle was retained after the sonication of the membrane, indicating that the modification was successfully achieved. The membrane with SiO(2)NPs@CF showed a flux of 14.3 kg(m(2)center dot h)(-1), 3.4 times higher than the unmodified version. The method presented herein avoids the complicated modification procedure offered by chemical step modification and, due to its simplicity, could be scalable to a commercial membrane.
- ItemTwo New Fluorinated Phenol Derivatives Pyridine Schiff Bases: Synthesis, Spectral, Theoretical Characterization, Inclusion in Epichlorohydrin-β-Cyclodextrin Polymer, and Antifungal Effect(2018) Carreño, Alexander; Rodríguez, Leonardo; Páez Hernández, Dayán; Martin-Trasanco, Rudy; Zúñiga, César; Oyarzún, Diego P.; Gacitúa Santelices, Manuel Alejandro; Schott Verdugo, Eduardo Enrique; Arratia Pérez, Ramiro; Fuentes, Juan A.