Research Groups

Based on the metallabis(dicarbollides) importance as a component of bio/materials (COP, sensors/biosensors, extractant, among others) that the group demonstrates since 2000, the synthesis of their derivatives continues as an important target nowadays. Metallabis(dicarbollides) either in a cooperative ion-pair with a ruthenium aqua complex or alone are very efficient photoredox catalysts in the oxidation of alkenes in water (>99% conversion). Smart redox-controlled fluorescent molecular switches based on metallacarborane‐perylenediimide conjugates with applications in biosensing and imaging probes have been developed. Light-Induced On/Off switching of the surfactant o-cobaltabis(dicarbollide) leads to promising applications, particularly in the field of nanomedicine.

Regarding biomedicine, research has aimed to develop of new cobaltabis(dicarbollide) derivatives for multimodal anti-cancer treatment (chemotherapy + BNCT). We have also studied the cobaltabis(dicarbollide) uptake/biomolecules-interaction/intracellular-location in Glioma Stem Cells by using a Synchrotron-Based Fourier-Transform Infrared Micro-Spectroscopy. We have developed radiolabeled cobaltabis(dicarbollide) anion–graphene oxide nanomaterials and photosensitizers as potential theragnostic agents (diagnosis + BNCT). We have reported the first alkaline earth salts of cobaltabis(dicarbollide) for biomedical applications. The reported salts are good candidates to apply in regenerative medicine and/or in bone defect repair. The development of red light-emitting carboranyl-based dyes for bioimaging has been reported.

Enhanced hydrolytic and thermal stability of metal-organic frameworks (MOFs), inherited from carborane, provided materials with new properties: a MOF/polypyrrole composite with improved capacitance as an electrode material. New photophysical properties have been also found.

HIGHLIGHTS 

• A Stand-Alone Cobalt Bis(Dicarbollide) Photoredox Catalyst Epoxidates Alkenes in Water at Extremely Low Catalyst Load
• Light-Induced On/Off Switching of the Surfactant Character of the o-Cobaltabis(dicarbollide) Anion with No Covalent Bond Alteration
• Tuning the architectures and luminescence properties of Cu(i) compounds of phenyl and carboranyl pyrazoles: the impact of 2D versus 3D aromatic moieties in the ligand backbone

The Nanoparticles and Nanocomposites Group has achieved the publication of remarkable results in several research activities, the majority of them as a result from a collaborative effort between the NN Group and complementary groups, hospitals or biomedical companies.

Some of the research has focused on controlling the synthesis of metal nanocrystals to produce 2D- Photonic crystals as UV-Visible photocatalysts. On the other hand, mesoporous silica nanorods filled with iron oxide nanoparticles were produced as catalytic nanomotors, in a study that was published in ChemNanoMat and included in the PhD thesis of Researcher Jan Grzelak, which opened a new line of research within the group.

Bacterial cellulose results close an excellent period where three interesting works were published. We demonstrated our mastering of the bio and soft- imprinting on bacterial films, the medical applications of BC films were proven by first culturing limbal stem cells for ocular surface regeneration, in a collaboration with the Skottman group at Tampere University, and we also demonstrated their potential to use BC films as tissue reinforcement in cases such as abdominal hernias in a collaboration with BBraun. Additionally, two outstanding Ph.D. students who contributed enormously to the BC topic successfully defended their thesis, Dr. Irene Anton-Sales and Dr. Soledad Roig-Sanchez.

Another publication in collaboration with the Vall d’Hebron Hospital assessed biocompatible poly(D-L-lactic-co-glycolic acid) (PLGA) nanocapsules functionalized with superparamagnetic iron oxide nanoparticles and Cy7.5 for magnetic targeting, magnetic resonance, and fluorescent molecular imaging as promising nanocarriers in endovascular administration to target brain delivery after stroke.

Also, first measurements have been obtained at a new high frequency measurement laboratory related to the ERC project Ferrites-by-desing for mm-wave and THz technologies (FeMiT).

HIGHLIGHTS 

• Large number of students and on-going PhD thesis (12) from all over the world. Permanent staff for NN group has increased, incorporating Maite Escobar as group manager and Pablo Guardia as Ramon y Cajal researcher.
• Patent Application: Screen-Printed Electrode, Manufacturing Method Thereof, Electrochemical Sensor Comprising Said Electrode For Detecting Water Pollutants, and Operating Method of Said Sensor. Inventors: Dr. César Fernandez-Sánchez, from CNM, and Wenchao Duan and Dr. Martí Gich from the NN Group.
• High attendance and participation to multiple scientific events and out-reach activities.

Our group has continued to make fundamental contributions to our understanding of materials properties, using both theoretical analysis and computational work. Some of the new insights are very relevant for technological applications:

We developed an exact theory of the long-range electrostatics in quasi-2D systems, enabling an accurate modeling of any physical property (such as interatomic forces at large distances) that depends on them. Our formalism provides a general platform for describing both intralayer and extralayer electrostatic interactions in 2D systems, with an applicability that goes well beyond the specifics of lattice dynamics. As a first application, we demonstrated its usefulness in describing higher-order electromechanical couplings, such as flexoelectricity.

The intrinsic difficulty in manipulating phonons is often ascribed to the fact that it is difficult to control their propagation by means of external fields. In the case of magnetic materials, we have shown that an external magnetic field can be used to manipulate the lattice by switching back and forth different magnetic orderings. We have tested these ideas in FeRh, a material that undergoes an antiferromagnetic (AFM) to ferromagnetic (FM) phase transition. We predict the existence of large magnetophononic effects, which allow for the modulation of the lattice heat conductivity via the application of magnetic fields. 

We have shown that what was known so far about group V transition metal trichalcogenides, the paradigmatic low-dimensional materials, is just a small portion of a very rich landscape. We proposed that these materials should exhibit a rich polymorphism and the different polymorphs should exhibit very diverse physical behaviors ranging from semiconductors with very anisotropic plasmonics to topological semimetals and charge density wave materials. These predictions have recently received experimental support. 

HIGHLIGHTS 

• Exact Long-Range Dielectric Screening and Interatomic Force Constants in Quasi-Two-Dimensional Crystals
• Dynamical tuning of the thermal conductivity via magnetophononic effects
• The rich polymorphism of layered NbS3: Charge density wave materials, stable metals and semiconductors

During 2021 we have obtained significant advances in different fields: we continued our investigations about the interactions of the SARS-CoV-2 virus with materials and in parallel we have obtained significant simulation results in fields as diverse as MOFs or ionic liquids combining DFT electronic structure calculations and Molecular Dynamics simulations. 

HIGHLIGHTS

• Using MD simulations, we predicted that the SARS-CoV-2 virus does not interact with sebaceous human skin but it has significant interactions with "clean" human skin (stratum corneum layer of skin).
• Using a combination of DFT and MD techniques we have correctly predicted that certain MOFs have strong selectivity of certain molecules in solution but do not show any selectivity for the same molecules in gas phase.
• MD simulations allow to understand the diffusion of CO2 in ionic liquids, a limiting factor for using captured CO2 for chemical synthesis

NANOMOL focuses on the study, synthesis and processing of molecular and polymeric materials for their integration in electronic devices and for biomedical applications.

During 2021, The e-MolMat group has progressed in the synthesis of novel organic polychlorinated trityl radicals (PTM) for a variety of applications. For instance, we demonstrated that the functionalisation of single walled carbon nanotubes (SWCNTs) with PTMs led to an increased triplet exciton population due to radical-enhanced intersystem crossing, which could provide access to the elusive triplet manifold in SWCNTs. Further, we optimized the performance of organic field-effect transistors (OFETs) based on the semiconductors diF-TES-ADT and Ph-BTBT-10. By blending these materials with binding polymers and controlling the coating speed, films with optimized polymorphism and with isotropic electrical characteristics were achieved. Further, electrolyte gated OFETs operating in water with an unprecedented stability were realized by the proper encapsulation of the semiconductors with a surfactant layer.

On January 2021, the EC and the European Medicines Agency (EMA) gave the Orphan Drug Designation to a new nanomedicine candidate for the treatment of Fabry rare disease, developed by the Nanomol-Bio group in the frame of the European project Smart4Fabry. The scale-up of this nanomedicine up-to Good Manufacturing Practice (GMP), which is a requisite for the arrival to the clinics is being performed under the European Open Innovation test bed Phoenix, started on March 2021. The group has progressed significantly on the development of new molecules and nanoparticles for bioimaging, in particular for Magnetic Resonance Imaging (MRI) and for advanced optical microscopies. These developments have been done in the frame of well-stablished interdisciplinary networks and projects, such as the Spanish biomedical network CIBER-BBN or European project Micro4Nano, started on October 2021.  During this year, Nanomol-BIO has also been actively engaged on the research and development of antimicrobial surfaces for biomedical uses, and on the development of patent protected microstructured hydrogels for cancer immunotherapy.

HIGHLIGHTS 

• Interaction of luminescent defects in carbon Nanotubes with covalently attached stable organic radicals
• Organisation of the "Veciana & Rovira: ONLINE Workshop on research and innovation in the field of molecular materials" on their 70th birthday. Additionally, a themed issue entitled “Materials for molecular electronics and magnetism” was published in J. Mater. Chem C. The NANOMOL Group contributed in this issue with two publications.
• Engineering DNA-Grafted Quatsomes as Stable Nucleic Acid-Responsive Fluorescent Nanovesicles 

The group would like to highlight achievements in four main research directions:

A highlighted Research Article in Science Advances showcases how to broaden the conditions in which Second sound, the thermal transport regime where heat is carried by temperature waves, can be experimentally observed, by driving the system with a rapidly varying temperature field. High-frequency second sound is demonstrated in bulk natural Ge between 7 K and room temperature, revealing the relaxation time and the propagation velocity of the heat waves.

Another Highlighted Research article in Energy & Environmental Science approaches the elusive influence of the donor and acceptor fractions on the photocurrent in organic photovoltaics using non-fullerene acceptors, by training artificial intelligence algorithms with self-consistent datasets consisting of thousands of data points obtained by high-throughput evaluation methods. Interestingly, we identify highly predictive models that only employ the materials band gaps, thus largely simplifying the rationale of the photocurrent-composition space.

Plasmonic crystals are organized arrays of clustered metal colloids capable of sustaining both localized and surface lattice plasmonic resonances. Easily fabricated by template-induced assembly, these plasmonic nanostructures can display tunable optical properties by changing the periodicity of the array. In our latest work in Advanced Optical Materials, we demonstrate that engineering the unit cell of the plasmonic crystal we can control the optical losses of the films. These findings are used to create plasmonic crystals out of metal colloids with resonances show quality factors beyond 60.

Finally, the high defect tolerance of metal halide perovskites is due to the very fact that most native point defects are shallow, which does not contribute to the non-radiative recombination of free carriers. In our Article in Advanced Optical Materials we presented a systematic study of shallow-defect signatures observed at low temperatures in the photoluminescence spectra of FAxMA1−xPbI3 perovskite single crystals. We observe a clear trend regarding shallow defects, indicating that the material becomes less prone to defect formation with increasing FA content.

HIGHLIGHTS 

• Observation of second sound in a rapidly varying temperature field in Ge. These results provide a route to investigate the potential of wave-like heat transport in almost any material, opening opportunities to control heat through its oscillatory nature.
• Predicting the photocurrent–composition dependence in organic solar cells. This study paves the way for the use of artificial intelligence and high-throughput experimentation to predict optimum composition in energy materials.
• Engineering Plasmonic Colloidal Meta‐Molecules for Tunable Photonic Supercrystals. In this manuscript, we demonstrate that the internal architecture of gold-nanoparticle meta-molecules can be engineered to obtain plasmonic supercrystals with high-quality factors (>60) for lattice plasmon resonances located in the visible spectral range.

The main activity of the group was focused on the development of hybrid nanocarbon-based electrodes for supercapacitors by means of two innovative laser technologies:

The first one is laser processing of graphene nanowall electrodes immersed in liquid metal organic precursors for the crystallization of pseudocapacitive transition metal oxide nanostructures on the graphene surface. This versatile and fast method allowed us to enhance several orders of magnitude the capacitance of the electrodes. Intense work was also carried out for scaling this technology to the industrial sector.

A second technique we explored is laser-induced deposition of complex electrodes constituted by heteroatom-doped reduced graphene oxide, carbon nanotubes and pseudocapacitive metal oxide nanostructures. Symmetric and asymmetric supercapacitors were fabricated with both aqueous and solid-state electrolytes, revealing noteworthy performance and excellent cycling stability upon tens of thousands of charge-discharge cycles at high current densities.

HIGHLIGHTS 

• Boost of Charge Storage Performance of Graphene Nanowall Electrodes by Laser-Induced Crystallization of Metal Oxide Nanostructures
• Laser fabrication of hybrid electrodes composed of nanocarbons mixed with cerium and manganese oxides for supercapacitive energy storage
• Two Gold Medal awards, one in the 25th edition of the International Exhibition of Inventions, INVENTICA 2021 (Iasi, Romania), and another in the 6th International Inventions Fair (Istambul, Turkey) for the patent “Procedure for obtaining a flexible electrode”.

The scientific challenges and achievements of SUMAN comprise the areas of superconducting materials and functional oxide nanocoatings for the fields of energy transition, high energy physics and information and communication technology, as described below.

Chemical solution deposition (CSD) has enable to demonstrate a novel high throughput TLAG-CSD method for high temperature superconducting nanocomposite films and coated conductors (CC) based on growth from transient liquids with ultrafast growth rates, where in-situ XRD synchrotron experiments are used to elucidate the kinetic growth mechanisms. Furthermore, in combination with compositional gradient inkjet printing, TLAG is being used for fast materials design using machine learning algorithms

Hybrid structures combining high-temperature superconducting films with soft ferromagnetic structures appears as a promising approach to manipulate textures for prospective energy-efficient memory devices. Volume-like resistive switching effects have been exploited to locally adjust the conductance response of transistor-like devices able to implement neuromorphic functionalities.

In addition, we have placed superconducting CC at the scene of future high energy circular accelerators and dark mater detectors for their low surface impedance properties at microwave frequencies, and nanocoated CC with current flow diverter architectures are now seriously considered also to protect high voltage dc grids.

In addition, CSD has demonstrated its versatility to prepare multifunctional complex oxides to be used in an all-oxide photovoltaic devices. The combination of CSD with a homebuilt atomic layer deposition reactor enabled the development of a cost-effective route to prepare free-standing multifunctional complex oxide membranes with atomic control facilitating the transition to crystalline and flexible devices.

Furthermore, complex oxide films have been used to engineer oxygen migration in the novel phenomena of homogeneous volume resistive switching. We have also continued studying other chemical methods like polymer assisted deposition (PAD) for thin films growth with dynamic magnetic and spin pumping properties.

HIGHLIGHTS

• New growth process for fabrication of superconducting layers being transferred to Sumitomo Electric Inds. obtained NGEU funds to build a dedicated installation at NCD-Sweet beamline of ALBA synchrotron.
• ICMAB enters in the RADES-CERN consortium by demonstrating that a superconducting resonant cavity for dark matter search outperforms existing technology.
• A Leonardo Grants from BBVA Foundation is awarded to SUMAN for sustainable synthesis of free-standing functional oxides for flexible photovoltaics.

Batteries based on multivalent ions (e.g. Ca2+, Mg2+) and metal anodes could enable very high energy densities. Bottlenecks to overcome for a study of such new chemistries are not only the development of electrolytes and cathodes enabling efficient cation diffusion, but also careful control of the passivation layer on metal anode and interfacial processes such as desolvation. Activities included the screening of new materials as potential cathodes for Ca metal batteries and characterization of the redox mechanism using operando diffraction, the study of the impact of the composition of the passivation layer, and the cation solvation structure on Ca plating kinetics.  In Li-O2 batteries, porous carbons with excellent behavior have been obtained by soaking in alcohol bacterial cellulose, facilitating more open structures on dried bacterial cellulose.

In the field of carbon nanomaterials, we have developed complementary protocols that allow the containment of materials in the cavities of carbon nanotubes (CNTs), namely by thermal annealing or by using fullerenes as corks. Using the thermal annealing strategy, CNTs have been filled with radionuclides and externally functionalized. The resulting constructs have proven therapeutically effective against cancer.

Neural electrostimulation through direct electric fields modifies cell repair in vitro when using large capacity hybrid electroactive materials. Recently, we have observed this effect in wireless bipolar electrochemistry electrostimulation conditions, and have proven that redox gradients are achieved across the material when cation intercalation is possible.

Supercritical CO2 has been used for the preparation of Metal-Organic Frameworks (MOF’s) and graphene oxide based aerogels, with applications in health and energy. Results in these fields include the preparation of MOFs, loaded with bioactive molecules for topical drug release, and MOF /Graphene Oxide composite aerogels for greenhouse gases adsorption and separation.

New nitride materials with electronic properties have been investigated. The introduction of nitride in an oxidic compound induces changes in bonding with the cations as a consequence of the different charge, electronegativity and polarizability with respect to the oxide anion. Oxynitride perovskite samples with high sintering degree have been obtained by a new synthetic approach at high temperature under N2 gas. Neutron diffraction studies indicate that the anion order is different from that observed in samples obtained by ammonolysis at lower temperatures, demonstrating that the N/O distribution is affected by the preparation method.

HIGHLIGHTS

• Rosa Palacín has been elected ECS Fellow and has received an IBA Research Award
• Iridium oxide redox gradient material: Operando X Ray absorption of Ir gradient oxidation states during IrOx bipolar electrochemistry
• HKUST-1 Metal-Organic Framework Nanoparticle/Graphene Oxide Nanocomposite Aerogels for CO2 and CH4 Adsorption and Separation

FunNanoSurf continues advancing in topics related to ICMAB’s Research Lines 4 and 5. Proof of this is the European project of which Dr. González-Campo is PI and the group publications in the field of nanoscience and nanotechnology in journals such as Angew. Chem., Dalton Trans., Chem-Eur. J., amongst others. In addition, two doctoral theses were defended this year and Dr. Gonzalez-Campo was the editor of a special issue of the Journal of Nanomaterials.

HIGHLIGHTS 

• Acquisition of the Horizon-EIC-2021-Pathfinderopen-01 grant (Ref.101046894), ICMAB IP: Arántzazu González-Campo, with a requested funding of 451.053 € and 4 years of duration, from 2022 to 2026.
• Defense of two doctoral theses: Electroactive self-assembled monolayers: p-donor/p-acceptor interactions to induce transport along of the surface by Sandra Giraldo, and Synthesis and characterization of curcuminoids and their derived polymeric systems by Laura Rodríguez.
• Participation in a total of 9 conferences/congresses/symposia (SMS-, EUROMAT-, SmallChem-, ElecMol-, rseqsymposium-, SBAN-, CGC- 2021) with a total of 7 oral communications, 1 invited talk and 1 poster.

Focused on unraveling and controlling the nanoscale structural and electronic properties of nanostructures and interfaces through surface engineering. Devoting special effort to organic materials, part of our investigation centers on organic semiconductors with relevance as active layers for electronic devices (such as organic solar cells and organic field effect transistors).

Our research spans from fundamental issues in organic growth to the electronic response of metal-organic junctions within two main research activities:

• Design and growth of ultrathin organic layers and organic/organic heterojunctions and
• Nanoscale properties of organic/electrode interfaces and devices

The research on epitaxial ferroelectric HfO2 films has progressed rapidly disclosing, among others, the crucial role of bottom electrodes on the stabilization of the ferroelectric phase and discerning the impact of (La,Zr) doping, thickness and dielectric capping effects on the properties of HfO2 films. This knowledge has been used to engineer ultrathin tunnel barriers for memory applications that mimic some brain-like functions.

The photoresponse of polar oxides has been exploited to control the ON/OFF states of ferroelectric memories and to show that polarization switching allows the reversing of the photocurrent. It has also been demonstrated that in hexagonal polar materials (i.e LuMnO3) the light-polarization dependence of the photocurrent contains fingerprints typically associated to bulk photovoltaic effect, rather than common photovoltaic sources.

Towards the development of superconducting quantum sensors (Transition-Edge Sensors, TES) for cryogenic radiation and particle detectors, we have achieved an understanding of the physics governing TES performances allowing to broaden its potential applications as low-energy photon detectors. Spintronic activities have been largely boosted by the incorporation of a new scientists under an ERC grant and whose leader has been awarded the 2021 IUPAP Young Scientist Prize in the field of Magnetism, in recognition for the outstanding contributions in the field of magnetic oxides for spintronics.

The growth and characterization of thin films of indium-free metallic electrodes based on early transition metal oxide (i.e. SrVO3) has led to the disruptive discovery that the effective electron-mass enhancement, responsible for its transparency at visible range, is due to electron-phonon coupling rather than electron-electron correlations, as commonly accepted, and that near-infrared plasmons can be excited in unpatterned films.

HIGHLIGHTS 

• Impact of La concentration on ferroelectricity of La-doped HfO2 epitaxial thin films. The study, carried out with epitaxial films, has determined the intrinsic effect of the doping content of La in ferroelectric HfO2 that was previously unclear due to the dispersion of the results reported in polycrystalline films.
• Electron–Phonon Coupling or electron correlations in early transition metals oxides. Epitaxial thin films of metallic SrVO3 display a plasma frequency that is best understood by assuming a strong electron-phonon coupling that dresses charger carriers.
• Optical control of ferroelectric memories. Photoabsorption in ferroelectric thin films allows the control of the resistance state of the devices.

The group’s main scientific goal is to generate both fundamental and applied knowledge for the implementation of functional oxide materials in novel technologies as spintronics. It focuses on functional properties, structural characterization of functional defects, nanodevices, complex oxide thin films, self-assembled materials and nanoparticles for life sciences 

In the Magnetic Material and Functional Oxides department at ICMAB, the activities of the Crystallography of Magnetic and Electronic Oxides and Surfaces group are addressed to explore, understand and develop new strongly correlated materials of interest in fundamental Condensed Matter research and as novel materials for the Information technologies.

The aim of the group is to explore, understand and develop new strongly correlated materials of interest in fundamental science, such as studies of intermolecular interactions, and in the improvement of methods for crystal structure determination from electron diffraction data. The group has developed the new through-the-substrate (tts) X-ray microdiffraction technique, integrated now at ALBA Synchrotron, and has a great expertise in nanocomposite porous materials, applied to different catalysis reactions.