Staff directory Claudio Roscini

Publications

2021

  • Encapsulation and sedimentation of nanomaterials through complex coacervation

    González-Monje P., Ayala García A., Ruiz-Molina D., Roscini C. Journal of Colloid and Interface Science; 589: 500 - 510. 2021. 10.1016/j.jcis.2020.12.067. IF: 7.489

    Hypothesis: Nanoparticles removal from seawage water is a health and environmental challenge, due to the increasing use of these materials of excellent colloidal stability. Herein we hypothesize to reach this objective through complex coacervation, a straightforward, low-cost process, normally accomplished with non-toxic and biodegradable macromolecules. Highly dense polymer-rich colloidal droplets (the coacervates) obtained from a reversible charge-driven phase separation, entrap suspended nanomaterials, allowing their settling and potential recovery. Experiments: In this work we apply this process to highly stable aqueous colloidal dispersions of different surface charge, size, type and state (solid or liquid). We systematically investigate the effects of the biopolymers excess and the nanomaterials concentration and charge on the encapsulation and sedimentation efficiency and rate. This strategy is also applied to real laboratory water-based wastes. Findings: Long-lasting colloidal suspensions are succesfully destabilized through coacervate formation, which ensures high nanomaterials encapsulation efficiencies (~85%), payloads and highly tranparent supernatants (%T ~90%), within two hours. Lower polymer excess induces faster clearance and less sediments, while preserving effective nanomaterials removal. Preliminary experiments also validate the method for the clearance of real water residuals, making complex coacervation a promising scalable, low-cost and ecofriendly alternative to concentrate, separate or recover suspended micro/nanomaterials from aqueous sludges. © 2020 Elsevier Inc.


2020

  • Highly transparent photochromic films with a tunable and fast solution-like response

    Torres-Pierna H., Ruiz-Molina D., Roscini C. Materials Horizons; 7 (10): 2749 - 2759. 2020. 10.1039/d0mh01073a. IF: 12.319

    The increasing interest towards photochromic films and their practical applications is driving researchers in the continuous design and synthesis of novel organic photochromic dyes with optimized performances in polymeric matrices. However, whereas their photochromic properties could be readily rationalized in organic liquid solutions, these could not be directly extrapolated to polymers as their performance changes unpredictably upon integration into a solid matrix. This leads to a time-consuming synthetic re-tuning of the dye chemical structure and/or the polymeric medium. To avoid this, herein we report an efficient, straightforward and universal strategy to embed commercial T-type organic photochromic dyes of different nature in a polymeric material without compromising their optimum solution absorption and isomerization kinetics. Our approach is based on trapping emulsified nanodroplets of a hydrophobic solution enclosing the dye into a hydrophilic polymeric matrix. The material is prepared through one single process using commercially available materials, without further modification of the components (the dye and the polymer matrix) nor requiring previous encapsulation steps. The films, which manifest true solution liquid-like and finely tunable photochromic behavior, are also highly transparent, recyclable, and scalable, and show enhanced fatigue resistance, making them highly suitable for different smart glass applications. © 2020 The Royal Society of Chemistry.


  • Shape Memory Polyurethane Microcapsules with Active Deformation

    Zhang F., Zhao T., Ruiz-Molina D., Liu Y., Roscini C., Leng J., Smoukov S.K. ACS Applied Materials and Interfaces; 2020. 10.1021/acsami.0c14882. IF: 8.758

    From smart self-tightening sutures and expandable stents to morphing airplane wings, shape memory structures are increasingly present in our daily life. The lack of methods for synthesizing intricate structures from them on the micron and submicron level, however, is stopping the field from developing. In particular, the methods for the synthesis of shape memory polymers (SMPs) and structures at this scale and the effect of new geometries remain unexplored. Here, we describe the synthesis of shape memory polyurethane (PU) capsules accomplished by interfacial polymerization of emulsified droplets. The emulsified droplets contain the monomers for the hard segments, while the continuous aqueous phase contains the soft segments. A trifunctional chemical cross-linker for shape memory PU synthesis was utilized to eliminate creep and improve the recovery ratios of the final capsules. We observe an anomalous dependence of the recovery ratio with the amount of programmed strain compared to previous SMPs. We develop quantitative characterization methods and theory to show that when dealing with thin-shell objects, alternative parameters to quantify recovery ratios are needed. We show that while achieving 94-99% area recovery ratios, the linear capsule recovery ratios can be as low as 70%. This quantification method allows us to convert from observed linear aspect ratios in capsules to find out unrecovered area strain and stress. The hollow structure of the capsules grants high internal volume for some applications (e.g., drug delivery), which benefit from much higher loading of active ingredients than polymeric particles. The methods we developed for capsule synthesis and programming could be easily scaled up for larger volume applications. Copyright © 2020 American Chemical Society.


  • Solid Materials with Near-Infrared-Induced Fluorescence Modulation

    Otaegui J.R., Rubirola P., Ruiz-Molina D., Hernando J., Roscini C. Advanced Optical Materials; 8 (21, 2001063) 2020. 10.1002/adom.202001063. IF: 8.286

    Solid molecular materials modulating their luminescent properties upon irradiation are typically based on photochromic dyes. Despite these are potentially interesting for applications such as anticounterfeiting, bioimaging, optical data storage, and writable/erasable devices, key features are preventing their use in marketable products: the lack of straightforward strategies to obtain near infrared (NIR) radiation-responding photochromic dyes and the dramatic response modification these molecules suffer in solids. Herein a photochrome-free approach is reported to achieve solid materials whose luminescence modulation is induced by NIR radiation. This strategy is based on the capacity of phase change materials (PCMs) to modify the emission properties of fluorescent dyes upon photothermally induced interconversion between their solid and liquid states. The preparation of several NIR-responsive thermofluorochromic materials of high fatigue resistance and nondestructive readout is illustrated and this approach is extended to different commercially available dyes, taking advantage of distinct fluorescence modulation mechanisms, providing, thus, color tunability. The modulation response is straightforwardly tuned by simply varying the irradiation power density, the gold nanoshell concentration, and/or the PCM type. This tunability allows to accomplish NIR-activated multistate thermofluorochromic materials and fast/slow/irreversible responses in NIR-writings/drawings of good spatial resolution, which can be of interest for barcodings, anticounterfeiting technologies and (re)writable devices. © 2020 Wiley-VCH GmbH


2019

  • Color-Tunable White-Light-Emitting Materials Based on Liquid-Filled Capsules and Thermally Responsive Dyes

    Vázquez-Mera N.A., Otaegui J.R., Sánchez R.S., Prats G., Guirado G., Ruiz-Molina D., Roscini C., Hernando J. ACS Applied Materials and Interfaces; 11 (19): 17751 - 17758. 2019. 10.1021/acsami.9b02169. IF: 8.456

    Color-tunable white-light-emitting materials are currently attracting much attention because of their potential applications in artificial lighting, sensing, and imaging. However, preparation of these systems from organic emitters is often cumbersome due to the interchromophoric interactions occurring upon solvent drying in the final solid materials, which can be hardly predicted and may lead to detrimental effects. To circumvent these obstacles, we have developed a new fabrication methodology that relies on dye encapsulation within liquid-filled capsules, thus enabling direct transfer of the luminescent properties from solution to the solid state and as such, rational design of miniaturized white-light-emitting materials. By introducing a thermally responsive chromophore into the capsules, these materials are further endowed with color tunability, which does not only allow ample modulation of the emitted color but also facilitate external fine control of the system so as to ensure precise realization of white light at the desired temperature and excitation wavelength. © 2019 American Chemical Society.


2018

  • Molecular-based upconversion in homo/heterogeneous liquids and in micro/nanostructured solid materials

    Latterini L., Massaro G., Penconi M., Gentili P.L., Roscini C., Ortica F. Dalton Transactions; 47 (26): 8557 - 8565. 2018. 10.1039/c8dt00020d. IF: 4.099

    Radiation upconversion can be an elegant and efficient strategy to minimize waste in energy harvesting and storage processes. The upconversion based on triplet-triplet annihilation processes of molecular dyes is a very versatile approach, but it requires a systematic photophysical characterization of the systems to optimize the upconversion yields and develop materials for technological applications. This paper represents an overview of the work carried out in our laboratories for the study and characterization of a molecular dye pair, 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrin platinum(ii) (PtOEP) and 1,3,6,8-tetraphenylpyrene (TPPy), suitable as the sensitizer and emitter, respectively, in a triplet-triplet annihilation based upconversion process. The investigation has been carried out in various media with increasing complexity. First, we used the dye pair to characterize the UC-efficiencies in homogeneous solvents of different viscosities and in oil-in-water microemulsions; then we explored the possibility to achieve upconversion in solid materials, like nanostructured silica matrices and liquid filled microcapsules. The possibility to achieve upconversion emission even in confined and rigid media has been confirmed and can inspire further applications of the process. © The Royal Society of Chemistry 2018.


  • Off/On Fluorescent Nanoparticles for Tunable High-Temperature Threshold Sensing

    Julià López A., Ruiz-Molina D., Landfester K., Bannwarth M.B., Roscini C. Advanced Functional Materials; 28 (28, 1801492) 2018. 10.1002/adfm.201801492. IF: 13.325

    Herein, a versatile threshold temperature sensor based on the glass transition temperature-triggered fluorescence activation of a dye/developer duo, encapsulated in polymeric nanoparticles is reported. The emission enhancement, detectable even by unaided eye is completed within a narrow temperature range and activates at adjustable threshold temperatures up to 200 °C. Fluorescence is chosen as sensing probe due to its high detection sensitivity together with an advanced spatial and temporal resolution. The strategy is based on nanoparticles prepared from standard thermoplastic polymers, a fluorescence developer, and the commercially available Rhodamine B base dye, a well-known and widely used fluorescent molecule. By making nanoparticles of different thermoplastic polymers, fast, abrupt, and irreversible disaggregation induced fluorescence enhancement, with tunable threshold temperature depending on the nanoparticles polymer glass transition is achieved. As a proof-of-concept for the versatility of this novel family of NPs, their use for sensing the thermal history of environments and surfaces exposed to the threshold temperature is showed. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim


  • Solvent-Tuned Supramolecular Assembly of Fluorescent Catechol/Pyrene Amphiphilic Molecules

    Nador F., Wnuk K., Roscini C., Solorzano R., Faraudo J., Ruiz-Molina D., Novio F. Chemistry - A European Journal; 24 (55): 14724 - 14732. 2018. 10.1002/chem.201802249. IF: 5.160

    The synthesis and structuration of a novel low-molecular-weight amphiphilic catechol compound is reported. The combination of a hydrophilic tail containing a catechol unit and a pyrene-based hydrophobic head favors solvent-tuned supramolecular assembly. Formation of hollow nanocapsules/vesicles occurs in concentrated solutions of polar protic and nonprotic organic solvents, whereas a fibril-like aggregation process is favored in water, even at low concentrations. The emission properties of the pyrene moiety allow monitoring of the self-assembly process, which could be confirmed by optical and electronic microscopy. In organic solvents and at low concentrations, this compound remains in its nonassembled monomeric form. As the concentration increases, the aggregation containing preassociated pyrene moieties becomes more evident up to a critical micellar concentration, at which vesicle-like structures are formed. In contrast, nanosized twist beltlike fibers are observed in water, even at low concentrations, whereas microplate structures appear at high concentrations. The interactions between molecules in different solvents were studied by using molecular dynamics simulations, which have confirmed different solvent-driven supramolecular interactions. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim


  • Sonochemical Synthesis of Optically Tuneable Conjugated Polymer Nanoparticles

    Bellacanzone C., Roscini C., del Carmen Ruiz Delgado M., Ponce Ortiz R., Ruiz-Molina D. Particle and Particle Systems Characterization; 35 (2, 1700322) 2018. 10.1002/ppsc.201700322. IF: 4.384

    The development of novel and simple methodologies for the obtaining of semiconductive polymer nanoparticles with fine-tuned optical properties represents nowadays a challenging research area as it involves a simultaneous chemical modification and nanostructuration of the polymer. Here, starting from poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene], this objective is achieved with the one-pot synthesis of oligomers with tunable conjugation length and their nanostructuration, employing a miniemulsion method. Ultrasound irradiation of heterogeneous mixtures leads to the formation of hypochlorous acid that disrupts the electronic conjugation through polymer chain cleavage. Moreover, control over the degree of the electronic conjugation of the oligomers, and therefore of the optical properties, is achieved simply by varying the polymer concentration of the initial solution. Finally, the presence of surfactants during the sonication allows for the formation of nanoparticles with progressive spectral shift of the main absorption (from λmax = 476 to 306 nm) and emission bands (from λmax = 597 to 481 nm). The integration of conducting polymer nanoparticles into polymeric matrices yields self-standing and flexible fluorescent films. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim


2017

  • Photochromism of dihydroazulene-based polymeric thin films

    Torres-Pierna H., Roscini C., Vlasceanu A., Broman S.L., Jevric M., Cacciarini M., Nielsen M.B. Dyes and Pigments; 145: 359 - 364. 2017. 10.1016/j.dyepig.2017.06.015. IF: 3.473

    We report on the preparation of polymeric thin films doped with six dihydroazulene derivatives whose photochromic properties were previously screened in organic solution studies. Spectroscopic investigations into the photochromic behavior of the polymeric matrices have given important insights on the stability and the photophysical properties of the photoswitches impregnated into polymers. © 2017 Elsevier Ltd


2016

  • Switchable colloids, thin-films and interphases based on metal complexes with non-innocent ligands: The case of valence tautomerism and their applications

    Vázquez-Mera N.A., Novio F., Roscini C., Bellacanzone C., Guardingo M., Hernando J., Ruiz-Molina D. Journal of Materials Chemistry C; 4 (25): 5879 - 5889. 2016. 10.1039/c6tc00038j. IF: 5.066

    Successful nanostructuration approaches developed in the last few years have allowed the preparation of robust valence tautomeric (VT) switchable (micro-/nano-) structures of a variety of dimensions and morphologies. These results are expected to definitely foster the implementation of these materials on hybrid molecular electronic devices but also endorse new applications in other different fields such as sensing, drug delivery or water remediation, among others. © The Royal Society of Chemistry 2016.


  • Temperature-Controlled Switchable Photochromism in Solid Materials

    Julià-López A., Hernando J., Ruiz-Molina D., González-Monje P., Sedó J., Roscini C. Angewandte Chemie - International Edition; 55 (48): 15044 - 15048. 2016. 10.1002/anie.201608408. IF: 11.709

    A novel strategy to achieve thermally switchable photochromism in solid materials is reported, which relies on the preparation of polymeric core–shell capsules containing solutions of photochromic dyes in acidic phase-change materials. Upon changing the phase (solid or liquid) of the encapsulated medium, one of the two photochromic states of the system is selectively stabilized on demand, allowing for reversible interconversion between direct and reverse photochromism when thermally scanning through the melting temperature of the phase-change material. This strategy, which does not require the addition of external agents or chemical modification of the dyes, proved to be general for different spiropyran photochromes and to be applicable to the fabrication of a variety of functional materials by simply embedding the capsules obtained into a solid matrix of choice. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim


  • Thermally Switchable Molecular Upconversion Emission

    Massaro G., Hernando J., Ruiz-Molina D., Roscini C., Latterini L. Chemistry of Materials; 28 (3): 738 - 745. 2016. 10.1021/acs.chemmater.5b03532. IF: 9.407

    In this work a novel strategy is introduced to achieve thermally switchable emission from photon upconversion (UC) systems based on organic dyes. When these molecules were dissolved at low concentrations in phase-change media, a reversible, sharp, and nearly complete interconversion from blue upconverted emission to red luminescence was observed around the solid-to-liquid transition of the system. This result was rationalized in terms of dye aggregation, which selectively occurs in the solid state and dramatically enhances the inter-chromophoric energy transfer processes leading to UC. Notably, this behavior is extendable to different media and dyes, which allows an easy tuning of the switching temperature and emission colors. In addition, with proper selection of the phase-change medium, our strategy permits facile preparation of solid molecular materials showing photon UC at room temperature and even at sub-micromolar dye concentrations. © 2016 American Chemical Society.


2015

  • Liquid-Filled Valence Tautomeric Microcapsules: A Solid Material with Solution-Like Behavior

    Vázquez-Mera N.A., Roscini C., Hernando J., Ruiz-Molina D. Advanced Functional Materials; 25 (26): 4129 - 4134. 2015. 10.1002/adfm.201501166. IF: 11.805

    The integration of stimuli-responsive valence tautomeric (VT) molecular systems into solid materials without compromising their functionality is a major bottleneck for the use of these compounds in high-added value applications. In this work, an innovative, simple, and universal approach is described to tackle this challenge based on the confinement of the active species into liquid-filled polymeric capsules. A microstructured solid with optimized solution-like behavior is obtained in this way, whose VT properties can be rationally tuned upon variation of the encapsulated solvent. Incorporation of the resulting capsules into thin films or other matrices of interest allows successful transfer of valence tautomerism from the liquid phase to solid materials, thus paving the way to the fabrication of functional devices based on spin transition compounds. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


2014

  • Bio- and Bioinspired Nanomaterials

    Ruiz-Molina D., Novio F., Roscini C. Bio- and Bioinspired Nanomaterials; 9783527335817: 1 - 457. 2014. 10.1002/9783527675821.

    A comprehensive overview of nanomaterials that are inspired by or targeted at biology, including some of the latest breakthrough research. Throughout, valuable contributions from top-level scientists illustrate how bionanomaterials could lead to novel devices or structures with unique properties. The first and second part cover the most relevant synthetic and bioinspired nanomaterials, including surfaces with extreme wettability properties, functional materials with improved adhesion or structural and functional systems based on the complex and hierarchical organization of natural composites. These lessons from nature are explored in the last section where bioinspired materials are proposed for biomedical applications, showing their potential for future applications in drug delivery, theragnosis, and regenerative medicine. A navigational guide aimed at advanced and specialist readers, while equally relevant for readers in research, academia or private companies focused on high added-value contributions. Young researchers will also find this an indispensable guide in choosing or continuing to work in this stimulating area, which involves a wide range of disciplines, including chemistry, physics, materials science and engineering, biology, and medicine. © 2015 Wiley-VCH Verlag GmbH & Co. KGaA. All rights reserved.


2013

  • Liquid-filled capsules as fast responsive photochromic materials

    Vázquez-Mera, N.; Roscini, C.; Hernando, J.; Ruiz-Molina, D. Advanced Optical Materials; 1: 631 - 636. 2013. 10.1002/adom.201300121. IF: 0.000