Person:
Espinal Viguri, Maialen

Profile Picture

Email Address

Birth Date

Research Projects

Organizational Units

Job Title

Last Name

Espinal Viguri

First Name

Maialen

person.page.departamento

Ciencias

ORCID

0000-0003-0227-9458

person.page.upna

811866

Name

Filters

2021 - 20243
Reset filters

Settings

Author: Cruz Quesada, Guillermo × Subject: Silica xerogels ×

Search Results

Now showing 1 - 3 of 3
  • Thumbnail Image
    PublicationOpen Access
    Hybrid xerogels doped with Tb(III) and Eu (III) and a water soluble Pybox ligand
    (2021) Cruz Quesada, Guillermo; Espinal Viguri, Maialen; Garrido Segovia, Julián José; Zientziak; Institute for Advanced Materials and Mathematics - INAMAT2; Ciencias
    Hybrid organic-inorganic siliceous materials (ORMOSiLs) are a key focus within the nanoscience area as they combine advantages of inorganic materials without losing characteristics intrinsic of organic molecules. In the past years, our research group has designed hybrid siliceous xerogels (HSXG) with porosities and surface chemistries on demand for a range of applications, such as coatings for optic fiber sensors [1]. Although hybrid xerogels are mainly amorphous materials, recent studies by our group have demonstrated that introducing specific organic fragments on the precursors can induce selforganization during the sol-gel process to obtain a series of transparent nanostructured HSXG [2]. In the present work, a step forward is taken in the applicability of this type of HSXG by doping them with Tb(III) or Eu (III) cations and a water-soluble pybox-based antenna ligand (Pybox-EG= 2,2′-(4-(2-Ethoxyethoxy)pyridine-2,6-diyl)bis(4,5-dihydrooxazole)). Inclusion of photoluminescence will provide the materials with new properties and therefore new applications in fiber optic sensors (FOS) or in solar cells devices.
  • Thumbnail Image
    PublicationOpen Access
    New hybrid organochlorinated xerogels
    (2021) Cruz Quesada, Guillermo; Espinal Viguri, Maialen; López Ramón, María Victoria; Garrido Segovia, Julián José; Zientziak; Institute for Advanced Materials and Mathematics - INAMAT2; Ciencias
    Hybrid silica xerogels (HSXG) combine the properties of organic and inorganic components in the same material, which makes them promising and versatile candidates for multiple applications. These materials can be easily prepared by the sol-gel process, which offers the possibility to obtain different morphologies. The incorporation of organic precursors plays an important role in their properties, hence, allowing the design of materials for specific applications such as coatings for optical fibers [1]. The aim of this work was to study the influence of the alkyl chain and chlorine atom on the morphological and textural properties of various hybrid materials produced by co-condensation. For this purpose, three series of hybrid xerogels were prepared by co-condensation of TEOS and a chloroalkyltriethoxysilane (TEOS:ClRTEOS, R = methyl, ethyl or propyl) at different molar ratios. The influence of the precursors on the structure and textural properties of the xerogels was studied by means of N2 adsorption, XRD (X-ray diffraction), 29Si NMR (nuclear magnetic resonance) and FE-SEM (Field Emission-scanning electron microscope) [2].
  • Thumbnail Image
    PublicationOpen Access
    From fundamental materials chemistry to sensing applications: unravelling the water adsorption mechanism of a luminescent optical fibre sensor membrane
    (Elsevier, 2024) Cruz Quesada, Guillermo; Rosales Reina, Beatriz; López Torres, Diego; Reinoso, Santiago; López Ramón, María Victoria; Arzamendi Manterola, María Cruz; Elosúa Aguado, César; Espinal Viguri, Maialen; Garrido Segovia, Julián José; Ciencias; Ingeniería Eléctrica, Electrónica y de Comunicación; Institute for Advanced Materials and Mathematics - INAMAT2; Institute of Smart Cities - ISC; Zientziak; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
    This work provides insight into the correlation between the luminescent response of a water-vapour optical fibre sensor and the textural properties of its lanthanide-doped silica coating. To this end, a library of 16 silica xerogels derived from combinations between 2 lanthanide dopants (EuIII, TbIII) and 8 antenna ligands was synthesised and characterised by photoluminescence spectroscopy and N2 and CO2 adsorption-desorption isotherms, among others. Based on the best luminescent response and most-suited porous texture, the material doped with TbIII and 2,2′-(4-(2-Ethoxyethoxy)pyridine-2,6-diyl)bis(4,5-dihydrooxazole) was selected to construct the probe. A film of this material was affixed to a commercial silica fibre by dip-coating and the resulting sensor was tested in a climatic chamber with relative humidity ranging from 20 to 90% to obtain normalised time-response and calibration curves at three temperatures. The response was linear up to certain water-vapour concentrations, beyond which abruptly changed to polynomial, acting against the sensor resolution. The adsorption mechanism was elucidated by comparing the isosteric enthalpies of adsorption calculated from the sensor calibration curves to those determined from the monolith water-vapour isotherms, revealing that capillary condensation in the membrane mesopores was the key phenomenon leading to the response deviating from linearity.