Rosa Batista - Academia.edu (original) (raw)

Papers by Rosa Batista

Sustainability

Hybrid biomaterials were engineered using the electrospinning technique, incorporating the dipept... more Hybrid biomaterials were engineered using the electrospinning technique, incorporating the dipeptide Boc–L-phenylalanyl–L-isoleucine into microfibers composed of biocompatible polymers. The examination by scanning electron microscopy affirmed the morphology of the microfibers, exhibiting diameters ranging between 0.9 and 1.8 µm. The dipeptide self-assembles into spheres with a hydrodynamic size between 0.18 and 1.26 µm. The dielectric properties of these microfibers were characterized through impedance spectroscopy where variations in both temperature and frequency were systematically studied. The investigation revealed a noteworthy rise in the dielectric constant and AC electric conductivity with increasing temperature, attributable to augmented charge mobility within the material. The successful integration of the dipeptide was substantiated through the observation of Maxwell–Wagner interfacial polarization, affirming the uniform dispersion within the microfibers. In-depth insight...

The crystal structure of a polymorph of Glycyl-L-alanine HI.H2O was synthesized from chiral cycli... more The crystal structure of a polymorph of Glycyl-L-alanine HI.H2O was synthesized from chiral cyclic Glycyl-L-alanine dipeptide, known to show molecular flexibility in different environments. The space group is polar (P21) and therefore pyroelectricity and optical second harmonic generation properties are allowed by symmetry. We report a pyroelectric coefficient as high as 45 µC/m2K occurring at 345 K, one order of magnitude smaller than the semi-organic ferroelectric Triglycine Sulphate (TGS) crystal. Furthermore, the polymorph displays a nonlinear optical effective coefficient of 0.14 pm/V, around 14 times smaller than the value from a phase-matched inorganic Barium Borate (BBO) single crystal.

Nanostructured dipeptide self-assemblies exhibiting quantum confinement are of great interest due... more Nanostructured dipeptide self-assemblies exhibiting quantum confinement are of great interest due to their potential applications in the field of materials science as optoelectronic materials for energy harvesting devices. Among those, aromatic cyclo-dipeptides containing the amino acid tryptophan are wide-band gap semiconductors displaying high mechanical rigidity, photoluminescence and piezoelectric properties to be used in power generation. In this work, we report the fabrication of hybrid systems based on chiral cyclo-dipeptide L-Tryptophan- L-Tryptophan incorporated into biopolymer electrospun fibers. The micro/nanofibers contain self-assembled nanospheres embedded into the polymer matrix are wide-band gap semiconductors (gap energy 3.8 eV), display blue photoluminescence and relevant piezoelectric and pyroelectric properties with coefficients as high as 57 pCN-1 and 35×10-6 Cm-2k-1, respectively. They are therefore promise systems for thermal sensing and energy harvesting appl...

Research on organic luminescent materials has been intensely pursued due to their importance in t... more Research on organic luminescent materials has been intensely pursued due to their importance in technological applications related to signaling, fluorescent biosensory/chemosensory materials, molecular switches and organic light emitting diodes (OLEDs). Organic fluorophores such as triphenylamine and benzimidazole derivatives have attracted a particular attention owing to their high emission efficiency being widely used as electron transporters and emitting layers for OLEDs. Recently, we have been investigating the potential of heterocyclic systems bearing functionalized (benz)imidazole derivatives exhibiting high thermal stability, interesting emissive and chemosensory properties. In this communication we report the synthesis and photophysical characterization of triphenylamine-benzimidazoles (compounds 1a-d) which were synthesized by a one step reaction through the Na2S2O4 reduction of several commercially available onitroanilines in the presence of triphenylamine aldehyde in DMSO...

Nanoscale Advances, 2020

Intense second harmonic generation emission was observed from a single nanofiber, corresponding t... more Intense second harmonic generation emission was observed from a single nanofiber, corresponding to an effective 2nd order susceptibility of 80 pm V−1, 4 times greater than the largest 2nd order susceptibility tensor element (21 pm V−1) for a macroscopic 3NA crystal.

Journal of Molecular Structure, 2020

New Journal of Chemistry, 2018

Probe 1, containing a BODIPY fluorophore, was able to selectively detect Hg(ii) in water–acetonit... more Probe 1, containing a BODIPY fluorophore, was able to selectively detect Hg(ii) in water–acetonitrile 95 : 5 solutions by marked colour changes and emission enhancement.

Materials Science Forum, 2006

Thienyl- and bithienyl-1,3-benzothiazoles 1 and 2 were synthesised by reacting various formyl thi... more Thienyl- and bithienyl-1,3-benzothiazoles 1 and 2 were synthesised by reacting various formyl thienyl and bithienyl derivatives with o-aminobenzenethiol in moderate to excellent yields. Evaluation of the solvatochromic and fluorescence properties of these compounds was carried out. Due to their strong fluorescence and also the strong push-pull character, benzothiazole derivatives 1 and 2 can be used as potential NLO materials or as fluorescent markers.

Materials Advances, 2022

Dual self-assembly of dipeptides into microspheres and microtapes. Quantum confinement in self-as... more Dual self-assembly of dipeptides into microspheres and microtapes. Quantum confinement in self-assembled structures of dipeptides. Self-assembly of dipeptides as nanospheres and nanotubes into blue luminescent electrospun fibers.

Nanoscale Advances, 2019

Dipeptide electrospun biomaterials are strong piezoelectric materials that can convert applied me... more Dipeptide electrospun biomaterials are strong piezoelectric materials that can convert applied mechanical forces into electricity.

Among the organic molecules, the so called push-pull or dipolar molecules (D-π-A) offer versatili... more Among the organic molecules, the so called push-pull or dipolar molecules (D-π-A) offer versatility of synthesis and ability to modulate their photophysical and photochemical properties. The cyanoacetic acid moiety has been used extensively as the acceptor group in D-π-A molecules motivated by its easy/inexpensive synthesis and ability to simultaneously act as a strong electron withdrawing moiety, as well as a stable anchoring group in dye-sensitized solar cells (DSSCs).[1] Our previous work on the synthesis and characterization of D-π-A chromophores in which the donor part (D) is represented by a p-excessive five-membered heteroaromatic system (pyrrole or thiophene) functionalized by electron donor groups and the acceptor part (A) is a strong electron acceptor group (“classical” or an electron-deficient heterocycle) has shown that they exhibit excellent solvatochromic, photochromic, emissive properties, good photovoltaic efficiencies, exceptional thermal stabilities and good to exc...

Proceedings of The 22nd International Electronic Conference on Synthetic Organic Chemistry

New push-pull second harmonic generation (SHG) chromophores 2 were synthesized in order to study ... more New push-pull second harmonic generation (SHG) chromophores 2 were synthesized in order to study their linear and nonlinear optical properties. The donor-acceptor π-conjugated systems 2 were prepared in good to excellent yields by a simple aldol-type condensation of the precursor aldehydes 1 with 6-nitro-2-methyl-1,3-benzothiazole in the presence of NaOH. Hyper-Rayleigh scattering in dioxane solutions was used to evaluate their second-order nonlinear optical properties. The experimental results showed that the optical (linear and nonlinear) properties are influenced by the electron-donor strength of the groups of the π-conjugated bridge. The vinyl-benzothiazole derivative 2b, with methoxyl as the donor group, exhibited the largest first hyperpolarizability β (1660 × 10−30 esu, 40 times greater than the standard reference pNA molecule) and the highest decomposition temperature (Td = 360 °C). The good balance between nonlinearity and thermal stability makes this compound a promising c...

The Journal of Organic Chemistry, Oct 29, 2013

The synthesis and comprehensive characterization of the excited states of four novel triphenylami... more The synthesis and comprehensive characterization of the excited states of four novel triphenylamine-benzimidazole derivatives has been undertaken in solution (ethanol and methylcyclohexane) at room temperature. This includes the determination of the absorption, fluorescence, and triplet-triplet absorption spectra, together with quantum yields of fluorescence, internal conversion, intersystem crossing, and singlet oxygen. From the overall data the radiative and radiationless rate constants could be obtained, and it is shown that the compounds are highly emissive with the radiative decay dominating, with more than 70% of the quanta loss through this deactivation channel. The basic structure of the triphenylamine-benzimidazole derivatives (1a) was modified at position 5 of the heterocyclic moiety with electron-donating (OH (1b), OCH3 (1c)) or electron-withdrawing groups (CN, (1d)). It was found that the photophysical properties remain basically unchanged with the different substitutions, although a marked Stokes shift was observed with 1d. The presence and nature of a charge-transfer transition is discussed with the help of theoretical (DFT and TDFT) data. All compounds displayed exceptionally high thermal stability (between 399 and 454 °C) as seen by thermogravimetric analysis.

Tetrahedron, Jun 28, 2012

9O Encontro Nacional Da Divisao De Catalise E Materiais Porosos, 2013