2018 |
Salazar, S; Guerra, D; Yutronic, N; Jara, P Removal of Aromatic Chlorinated Pesticides from Aqueous Solution Using Β-Cyclodextrin Polymers Decorated with Fe₃o₄ Nanoparticles Artículo de revista Polymers, 10 (9), pp. 1038, 2018, ISSN: 2073-4360. Resumen | Enlaces | BibTeX | Etiquetas: adsorption, cyclodextrin magnetic nano nanoparticles, nanosponges, sorbents, treatment, water β-cyclodextrin @article{RN393, title = {Removal of Aromatic Chlorinated Pesticides from Aqueous Solution Using Β-Cyclodextrin Polymers Decorated with Fe₃o₄ Nanoparticles}, author = { S. Salazar and D. Guerra and N. Yutronic and P. Jara}, url = {https://www.ncbi.nlm.nih.gov/pubmed/30960963, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6403796/}, doi = {10.3390/polym10091038}, issn = {2073-4360}, year = {2018}, date = {2018-01-01}, journal = {Polymers}, volume = {10}, number = {9}, pages = {1038}, abstract = {This article describes the sorption properties of cyclodextrin polymers (nanosponges; NS) with the pesticides 4-chlorophenoxyacetic acid (4-CPA) and 2,3,4,6-tetrachlorophenol (TCF), including an evaluation of its efficiency and a comparison with other materials, such as granulated activated carbon (GAC). NS-pesticide complexes were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray powder diffraction (XRPD), proton nuclear magnetic resonance (¹H-NMR), UV⁻VIS, and thermogravimetric analysis (TGA). This confirms the interactions of the guests with nanosponges and shows that the polymers have favorable sorption capacities for chlorinated aromatic guests. Our studies also show that the inclusion complex is predominantly favored for NS/CPA rather than those formed between TCF and NS due to the size of the adsorbate and steric effects. Sorption studies carried with repeated cycles demonstrate that NS polymers could be an improved technology for pollutant removal from aquatic environments, as they are very efficient and reusable materials. Our experiments and characterization by SEM, EDS, UV⁻VIS, and magnetization saturation (VSM) also show that NS is an optimal substrate for the deposition of magnetite nanoparticles, thus improving the usefulness and properties of the polymer, as the nanosponges could be retrieved from aqueous solution with a neodymium magnet without losing its efficiency as a pesticide sorbent.}, keywords = {adsorption, cyclodextrin magnetic nano nanoparticles, nanosponges, sorbents, treatment, water β-cyclodextrin}, pubstate = {published}, tppubtype = {article} } This article describes the sorption properties of cyclodextrin polymers (nanosponges; NS) with the pesticides 4-chlorophenoxyacetic acid (4-CPA) and 2,3,4,6-tetrachlorophenol (TCF), including an evaluation of its efficiency and a comparison with other materials, such as granulated activated carbon (GAC). NS-pesticide complexes were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray powder diffraction (XRPD), proton nuclear magnetic resonance (¹H-NMR), UV⁻VIS, and thermogravimetric analysis (TGA). This confirms the interactions of the guests with nanosponges and shows that the polymers have favorable sorption capacities for chlorinated aromatic guests. Our studies also show that the inclusion complex is predominantly favored for NS/CPA rather than those formed between TCF and NS due to the size of the adsorbate and steric effects. Sorption studies carried with repeated cycles demonstrate that NS polymers could be an improved technology for pollutant removal from aquatic environments, as they are very efficient and reusable materials. Our experiments and characterization by SEM, EDS, UV⁻VIS, and magnetization saturation (VSM) also show that NS is an optimal substrate for the deposition of magnetite nanoparticles, thus improving the usefulness and properties of the polymer, as the nanosponges could be retrieved from aqueous solution with a neodymium magnet without losing its efficiency as a pesticide sorbent. |
2017 |
Celis, F; Garcia, M; Diaz-Fleming, G; Campos-Vallette, M A Review of Raman, Surface-Enhanced Raman Scattering (Sers) and Related Spectroscopic Techniques Applied to Biomolecules in Biomaterials Artículo de revista Journal of the Chilean Chemical Society, 62 (3), pp. 3627-3632, 2017, ISSN: 0717-9707. Resumen | Enlaces | BibTeX | Etiquetas: adsorption, biomolecules, bone, calcium-phosphate, cells, fragments, gold living nanoparticles, peptide raman, sers, silver terminal ultraviolet @article{RN368, title = {A Review of Raman, Surface-Enhanced Raman Scattering (Sers) and Related Spectroscopic Techniques Applied to Biomolecules in Biomaterials}, author = { F. Celis and M. Garcia and G. Diaz-Fleming and M. Campos-Vallette}, url = {/brokenurl#<Go to ISI>://WOS:000417443500015}, issn = {0717-9707}, year = {2017}, date = {2017-01-01}, journal = {Journal of the Chilean Chemical Society}, volume = {62}, number = {3}, pages = {3627-3632}, abstract = {The development of new biomaterials has gained increasing attention in the last decade. One of the most important aspects in the development of these new materials is to understand the chemical cues presents in the native niche. Among all the techniques currently available for measuring those interactions, Raman spectroscopy offers a unique and non-invasive tool for exploring the behavior of the components within a given biomaterial and their surrounding microenvironment. This technique exploits the unique molecular vibrational fingerprints for pinpointing those interactions. The vibrational response can be improved to the single molecule level, in the presence of metal nanoparticles (NPs) with plasmonic properties (silver, gold and copper) in the so-called SurfaceEnhanced Raman Scattering (SERS), which can be used for in-situ measurements. Another technique recently developed is the Shell-Isolated Nanoparticle-Enhanced Raman Spectroscopy (SHINERS), which overcomes signal contamination from chemical interactions between biomolecules and the metal surface; it does this by coating the metal surface with an inert layer of alumina or silica. In the present contribution, the role and the applications of Raman, SERS and related spectroscopic techniques in the study of biomolecules in biomaterials are reviewed and discussed.}, keywords = {adsorption, biomolecules, bone, calcium-phosphate, cells, fragments, gold living nanoparticles, peptide raman, sers, silver terminal ultraviolet}, pubstate = {published}, tppubtype = {article} } The development of new biomaterials has gained increasing attention in the last decade. One of the most important aspects in the development of these new materials is to understand the chemical cues presents in the native niche. Among all the techniques currently available for measuring those interactions, Raman spectroscopy offers a unique and non-invasive tool for exploring the behavior of the components within a given biomaterial and their surrounding microenvironment. This technique exploits the unique molecular vibrational fingerprints for pinpointing those interactions. The vibrational response can be improved to the single molecule level, in the presence of metal nanoparticles (NPs) with plasmonic properties (silver, gold and copper) in the so-called SurfaceEnhanced Raman Scattering (SERS), which can be used for in-situ measurements. Another technique recently developed is the Shell-Isolated Nanoparticle-Enhanced Raman Spectroscopy (SHINERS), which overcomes signal contamination from chemical interactions between biomolecules and the metal surface; it does this by coating the metal surface with an inert layer of alumina or silica. In the present contribution, the role and the applications of Raman, SERS and related spectroscopic techniques in the study of biomolecules in biomaterials are reviewed and discussed. |
2016 |
González-Navarrete, J; Toral, M I; Leiva, A; Yazdani-Pedram, M; Rios, H; Briones, X; Urzúa, M Adsorption of as (V) by Poly (N-Octyl-4-Vinylpyridinium) Bromide: Determination of as (V) by Direct Measurement of Fluorescence on the Solid Phase Artículo de revista Reactive & Functional Polymers, 109 , pp. 112-119, 2016, ISSN: 1381-5148. Resumen | Enlaces | BibTeX | Etiquetas: adsorption, arsenate, arsenic arsenic, atomic-absorption-spectrometry, carbon drinking-water, extraction, fluorescence, heavy-metal ions, nanotubes, performance phase, preconcentration, removal, samples, solid toxic water @article{RN277, title = {Adsorption of as (V) by Poly (N-Octyl-4-Vinylpyridinium) Bromide: Determination of as (V) by Direct Measurement of Fluorescence on the Solid Phase}, author = { J. Gonz\'{a}lez-Navarrete and M.I. Toral and A. Leiva and M. Yazdani-Pedram and H. Rios and X. Briones and M. Urz\'{u}a}, url = {/brokenurl#<Go to ISI>://WOS:000390510200015}, doi = {10.1016/j.reactfunctpolym.2016.10.011}, issn = {1381-5148}, year = {2016}, date = {2016-01-01}, journal = {Reactive & Functional Polymers}, volume = {109}, pages = {112-119}, publisher = {2016 Elsevier B.V.}, abstract = {Adsorption of As (V) by poly (N-octyl-4-vinylpyridinium) bromide (P4VPyC8), used as solid phase, was studied. Determination of As (V) was carried out by direct measurement of the fluorescence intensity on the solid phase. Adsorption variables were optimized for obtaining optimum values of pH and agitation time, where pH 9.0 and 60 min were established as optimum values. The adsorption of arsenic (V) was characterized by infrared spectroscopy, thermogravimetric analysis and scanning electron microscopy. It was found that the fluorescence of the solid phase increases as the concentration of arsenic increases. Linearity was observed in the concentration range 6.80 to 90.0 mu g L-1. The detection limit for determination of As (V) by this method was 2.24 mu g L-1 and the relative standard deviation (RSD) was 1.72%. The amount of retained As (V) was 0.154 mg/g of solid phase. The determination of As (V) in a sample of tap water by this method was well compared with the value reported by an external certified laboratory. Therefore, the method of analysis proposed here could be used as a screening methodology for monitoring the fulfillment of the norm for arsenic concentration in tap water.}, keywords = {adsorption, arsenate, arsenic arsenic, atomic-absorption-spectrometry, carbon drinking-water, extraction, fluorescence, heavy-metal ions, nanotubes, performance phase, preconcentration, removal, samples, solid toxic water}, pubstate = {published}, tppubtype = {article} } Adsorption of As (V) by poly (N-octyl-4-vinylpyridinium) bromide (P4VPyC8), used as solid phase, was studied. Determination of As (V) was carried out by direct measurement of the fluorescence intensity on the solid phase. Adsorption variables were optimized for obtaining optimum values of pH and agitation time, where pH 9.0 and 60 min were established as optimum values. The adsorption of arsenic (V) was characterized by infrared spectroscopy, thermogravimetric analysis and scanning electron microscopy. It was found that the fluorescence of the solid phase increases as the concentration of arsenic increases. Linearity was observed in the concentration range 6.80 to 90.0 mu g L-1. The detection limit for determination of As (V) by this method was 2.24 mu g L-1 and the relative standard deviation (RSD) was 1.72%. The amount of retained As (V) was 0.154 mg/g of solid phase. The determination of As (V) in a sample of tap water by this method was well compared with the value reported by an external certified laboratory. Therefore, the method of analysis proposed here could be used as a screening methodology for monitoring the fulfillment of the norm for arsenic concentration in tap water. |
Mera-Adasme, R; Xu, W H; Sundholm, D; Mendizabal, F Calculations of the Light Absorption Spectra of Porphyrinoid Chromophores for Dye-Sensitized Solar Cells Artículo de revista Physical Chemistry Chemical Physics, 18 (40), pp. 27877-27884, 2016, ISSN: 1463-9076. Resumen | Enlaces | BibTeX | Etiquetas: adsorption, approximation, basis-sets, correlation-energy, dft, efficiency hartree-fock, model, organic-dyes, performance, screening @article{RN305, title = {Calculations of the Light Absorption Spectra of Porphyrinoid Chromophores for Dye-Sensitized Solar Cells}, author = { R. Mera-Adasme and W.H. Xu and D. Sundholm and F. Mendizabal}, url = {/brokenurl#<Go to ISI>://WOS:000385180600020}, doi = {10.1039/c6cp04627d}, issn = {1463-9076}, year = {2016}, date = {2016-01-01}, journal = {Physical Chemistry Chemical Physics}, volume = {18}, number = {40}, pages = {27877-27884}, abstract = {Solar power is a strong alternative to the currently used fossil fuels in order to satisfy the world's energy needs. Among them, dye-sensitized solar cells (DSSC) represent a low-cost option. Efficient and cheap dyes are currently needed to make DSSCs competitive. Computational chemistry can be used to guide the design of new light-absorbing chromophores. Here, we have computationally studied the lowest excited states of ZnPBAT, which is a recently synthesized porphyrinoid chromophore with high light-absorption efficiency. The calculations have been performed at ab initio correlated levels of theory employing second-order coupled clusters (CC2) and algebraic diagrammatic construction using second order (ADC(2)) methods and by performing density functional theory (DFT) calculations using the time-dependent DFT (TDDFT) approach for excitation energies. The ultraviolet-visible (UV-vis) spectrum calculated at the ADC(2) and CC2 levels agrees well with the experimental one. The calculations show that ZnPBAT has six electronic transitions in the visible range of the absorption spectrum. The ab initio correlated calculations and previously reported experimental data have been used to assess the performance of several well-known density functionals that have been employed in the present TDDFT study. Solvent effects have been estimated by using the conductor-like screening model (COSMO). The influence of the addition of a TiO2 cluster to the chromophore systems has also been investigated. The results indicate that both CAM-B3LYP and Becke's "half-and-half'' (BHLYP) density functionals are appropriate for the studies of excitation energies in the blue range of the visible spectrum for these kinds of porphyrinoid chromophores, whereas the excitation energies of the Q band calculated at the ab initio correlated level are more accurate than those obtained in the present TDDFT calculations. The inclusion of solvent effects has a modest influence on the spectrum of the protonated form of the studied chromophores, whereas solvent models are crucial when studying the absorption spectrum of the anionic chromophore. The calculated UV-vis spectrum for the chromophore anion is not significantly affected by attaching a TiO2 cluster to it.}, keywords = {adsorption, approximation, basis-sets, correlation-energy, dft, efficiency hartree-fock, model, organic-dyes, performance, screening}, pubstate = {published}, tppubtype = {article} } Solar power is a strong alternative to the currently used fossil fuels in order to satisfy the world's energy needs. Among them, dye-sensitized solar cells (DSSC) represent a low-cost option. Efficient and cheap dyes are currently needed to make DSSCs competitive. Computational chemistry can be used to guide the design of new light-absorbing chromophores. Here, we have computationally studied the lowest excited states of ZnPBAT, which is a recently synthesized porphyrinoid chromophore with high light-absorption efficiency. The calculations have been performed at ab initio correlated levels of theory employing second-order coupled clusters (CC2) and algebraic diagrammatic construction using second order (ADC(2)) methods and by performing density functional theory (DFT) calculations using the time-dependent DFT (TDDFT) approach for excitation energies. The ultraviolet-visible (UV-vis) spectrum calculated at the ADC(2) and CC2 levels agrees well with the experimental one. The calculations show that ZnPBAT has six electronic transitions in the visible range of the absorption spectrum. The ab initio correlated calculations and previously reported experimental data have been used to assess the performance of several well-known density functionals that have been employed in the present TDDFT study. Solvent effects have been estimated by using the conductor-like screening model (COSMO). The influence of the addition of a TiO2 cluster to the chromophore systems has also been investigated. The results indicate that both CAM-B3LYP and Becke's "half-and-half'' (BHLYP) density functionals are appropriate for the studies of excitation energies in the blue range of the visible spectrum for these kinds of porphyrinoid chromophores, whereas the excitation energies of the Q band calculated at the ab initio correlated level are more accurate than those obtained in the present TDDFT calculations. The inclusion of solvent effects has a modest influence on the spectrum of the protonated form of the studied chromophores, whereas solvent models are crucial when studying the absorption spectrum of the anionic chromophore. The calculated UV-vis spectrum for the chromophore anion is not significantly affected by attaching a TiO2 cluster to it. |
2018 |
Removal of Aromatic Chlorinated Pesticides from Aqueous Solution Using Β-Cyclodextrin Polymers Decorated with Fe₃o₄ Nanoparticles Artículo de revista Polymers, 10 (9), pp. 1038, 2018, ISSN: 2073-4360. |
2017 |
A Review of Raman, Surface-Enhanced Raman Scattering (Sers) and Related Spectroscopic Techniques Applied to Biomolecules in Biomaterials Artículo de revista Journal of the Chilean Chemical Society, 62 (3), pp. 3627-3632, 2017, ISSN: 0717-9707. |
2016 |
Adsorption of as (V) by Poly (N-Octyl-4-Vinylpyridinium) Bromide: Determination of as (V) by Direct Measurement of Fluorescence on the Solid Phase Artículo de revista Reactive & Functional Polymers, 109 , pp. 112-119, 2016, ISSN: 1381-5148. |
Calculations of the Light Absorption Spectra of Porphyrinoid Chromophores for Dye-Sensitized Solar Cells Artículo de revista Physical Chemistry Chemical Physics, 18 (40), pp. 27877-27884, 2016, ISSN: 1463-9076. |