Artículos SCI
2019
2019
Reactividad de Sólidos
Design of highly stabilized nanocomposite inks based on biodegradable polymer-matrix and gold nanoparticles for Inkjet Printing
Begines, Belen; Alcudia, Ana; Aguilera-Velazquez, Raul; Martinez, Guillermo; He, Yinfeng; Wildman, Ricky; Sayagues, Maria-Jesus; Jimenez-Ruiz, Aila; Prado-Gotor, RafaelScientific Reports, 9 (2019) 16097
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![](https://icms.us-csic.es/sites/icms.us-csic.es/files/41598_2019_52314_Fig1_HTML.png)
Nowadays there is a worldwide growing interest in the Inkjet Printing technology owing to its potentially high levels of geometrical complexity, personalization and resolution. There is also social concern about usage, disposal and accumulation of plastic materials. In this work, it is shown that sugar-based biodegradable polyurethane polymers exhibit outstanding properties as polymer-matrix for gold nanoparticles composites. These materials could reach exceptional stabilization levels, and demonstrated potential as novel robust inks for Inkjet based Printing. Furthermore, a physical comparison among different polymers is discussed based on stability and printability experiments to search for the best ink candidate. The University of Seville logo was printed by employing those inks, and the presence of gold was confirmed by ToF-SIMS. This approach has the potential to open new routes and applications for fabrication of enhanced biomedical nanometallic-sensors using stabilized AuNP.
Noviembre, 2019 | DOI: 10.1038/s41598-019-52314-2
Materiales Avanzados
Phyllite clays as raw materials replacing cement in mortars: Properties of new impermeabilizing mortars
Arce, Carolina; Garzon, Eduardo; Sanchez-Soto, Pedro J.Construction and Building Materials, 224 (2019) 348-358
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![](https://icms.us-csic.es/sites/icms.us-csic.es/files/1-s2_237.png)
The aim of this investigation was to determine the suitability of phyllite clays as a raw construction material. For that purpose, the cement in mortars was replaced by a phyllite clay (0–90 wt%) making this study the first of its kind to be performed. These materials were prepared with different water proportions according to the water content and water/cement and water/binder (cement plus phyllite clay) relationships. A comparative study of the most important properties of the resulting experimental mortars was carried out, such as apparent density, water retentivity, consistency and mechanical strength (flexural and compressive strength), along with an evaluation of the pozzolanic activity and permeability. The results showed that the increase of phyllite decreases the apparent density, the consistency and mechanical properties of the mortar, while water retentivity fluctuates. Good correlations (R2 > 0.84) were obtained between flexural and compressive strength for the mortars after 28 days of curing. Pozzolanic activity was observed at cement replacement of 80 wt% of phyllite. Moreover, new impermeabilizing mortars constituted by phyllite clay and cement have been obtained according to the low coefficients of permeability. Taking into account the findings of this research, phyllite clays can be applied as raw construction materials with savings derived from replacing cement in mortars and the low energy consumption involved in their production. However, the present study concluded that the use of phyllite clays did not improve the mechanical strength of these new mortars but, in contrast, they can be applied for impermeabilization purposes in Construction and Civil Engineering.
Noviembre, 2019 | DOI: 10.1016/j.conbuildmat.2019.07.081
Materiales Coloidales
Encapsulation of Upconversion Nanoparticles in Periodic Mesoporous Organosilicas
Rahmani, S; Jimenez, CM; Aggad, D; Gonzalez-Mancebo, D; Ocana, M; Ali, LMA; Nguyen, C; Nieto, AIB; Francolon, N; Oliveiro, E; Boyer, D; Mahiou, R; Raehm, L; Gary-Bobo, M; Durand, JO; Charnay, CMolecules, 24 (2019) 22
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![](https://icms.us-csic.es/sites/icms.us-csic.es/files/molecules-24-04054-g001-550.png)
(1) Background: Nanomedicine has recently emerged as a promising field, particularly for cancer theranostics. In this context, nanoparticles designed for imaging and therapeutic applications are of interest. We, therefore, studied the encapsulation of upconverting nanoparticles in mesoporous organosilica nanoparticles. Indeed, mesoporous organosilica nanoparticles have been shown to be very efficient for drug delivery, and upconverting nanoparticles are interesting for near-infrared and X-ray computed tomography imaging, depending on the matrix used. (2) Methods: Two different upconverting-based nanoparticles were synthesized with Yb3+-Er3+ as the upconverting system and NaYF4 or BaLuF5 as the matrix. The encapsulation of these nanoparticles was studied through the sol-gel procedure with bis(triethoxysilyl)ethylene and bis(triethoxysilyl)ethane in the presence of CTAB. (3) Results: with bis(triethoxysilyl)ethylene, BaLuF5: Yb3+-Er3+, nanoparticles were not encapsulated, but anchored on the surface of the obtained mesoporous nanorods BaLuF5: Yb3+-Er3+@Ethylene. With bis(triethoxysilyl)ethane, BaLuF5: Yb3+-Er3+ and NaYF4: Yb3+-Er(3+)nanoparticles were encapsulated in the mesoporous cubic structure leading to BaLuF5: Yb3+-Er3+@Ethane and NaYF4: Yb3+-Er3+@Ethane, respectively. (4) Conclusions: upconversion nanoparticles were located on the surface of mesoporous nanorods obtained by hydrolysis polycondensation of bis(triethoxysilyl)ethylene, whereas encapsulation occurred with bis(triethoxysilyl)ethane. The later nanoparticles NaYF4: Yb3+-Er3+@Ethane or BaLuF5: Yb3+-Er3+@Ethane were promising for applications with cancer cell imaging or X-ray-computed tomography respectively.
Noviembre, 2019 | DOI: 10.3390/molecules24224054
Reactividad de Sólidos
Graphene nanoplatelets for electrically conductive 3YTZP composites densified by pressureless sintering
Lopez-Pernia, C; Gallardo-Lopez, A; Morales-Rodriguez, A; Poyato, RJournal of the European Ceramic Society, 39 (2015) 4435-4439
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![](https://icms.us-csic.es/sites/icms.us-csic.es/files/1-s2_222.png)
3 mol% yttria tetragonal zirconia polycrystalline (3YTZP) ceramic composites with 2.5, 5 and 10 vol% graphene nanoplatelets (GNP) were pressureless sintered in argon atmosphere between 1350 and 1450 degrees C. The effects of the GNP content and the sintering temperature on the densification, microstructure and electrical properties of the composites were investigated. An isotropic distribution of GNP surrounding ceramic regions was exhibited regardless the GNP content and sintering temperature used. Electrical conductivity values comparable to the ones of fully dense composites prepared by more complex techniques were obtained, even though full densification was not achieved. While the composite with 5 vol% GNP exhibited electrical anisotropy with a semiconductor-type behaviour, the composite with 10 vol% GNP showed an electrically isotropic metallic-type behaviour.
Noviembre, 2019 | DOI: 10.1016/j.jeurceramsoc.2019.05.067
Materiales Coloidales
Monodisperse Gold Cuboctahedral Nanocrystals Directly Synthesized in Reverse Micelles: Preparation, Colloidal Dispersion in Organic Solvents and Water, Reversible Self-Assembly and Plasmonic Properties
Luna, C; Castaneda-Rodriguez, D; Barriga-Castro, ED; Nunez, NO; Mendoza-Resendez, RLangmuir, 34 (2019) 14291-14299
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![](https://icms.us-csic.es/sites/icms.us-csic.es/files/la9b02374_0012.png)
The synthesis of organic-solvent-dispersible gold nanoparticles in reverse micelles of didodecyldimethylammonium bromide (DDAB) is revisited in the present investigation. Some parameters of synthesis, specifically the reaction volume and the concentration of the reducing agent, were slightly modified obtaining directly monodisperse gold nanocrystals (AuNCs) without the need to use additional active surfactants or additional treatments such as digestive ripening. Interestingly, most of the obtained AuNCs display the same exposed crystalline faces composed of six bounding facets (four {111} faces and two {002} faces), corresponding to single-crystalline face-centered cubic nanoparticles with a cuboctahedron shape. When these AuNCs are subsequently functionalized with 1-decanethiol (C10H21SH) or 1-dodecanethiol (C12H25SH), they don’t experience significant changes in their size or crystalline texture, however, they self-aggregate directly in the suspension at room temperature into faceted supramolecular structures and exhibit collective plasmonic excitations. Such self-organization is reversible under heating treatments allowing the observation of the influence of the AuNCs aggregation state on their plasmonic properties. Fourier transform infrared spectroscopy reveals that thiols only replace partially the DDAB molecules, and thus, DDAB molecules remain present in the thiol-capped AuNCs. To turn the thiol-capped nanocrystals into water-dispersible nanocrystals and extend their technological potential, they are stabilized with poloxamer 407 obtaining highly stable purple colloids in water.
Noviembre, 2019 | DOI: 10.1021/acs.langmuir.9b02374
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