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VOC-free mild conditions curing reaction of a petroleum-based epoxy (DGEBA) or a bio-based epoxy (DGEMHQ) in a tricomponent reaction platform with a recyclable imidazolium-based IL (BMImCl) and dicarboxylic acid (succinic acid).

[EN] For producing second-generation ethanol (cellulosic ethanol) and other value-added bioproducts, magnetic graphene oxide (GO-MNP) was synthesized in this work and used as the immobilization support for an industrial cellulase-and xylanase-containing preparation. GO-MNP characterization by TEM, SEM and ATR-FTIR spectroscopy showed that the magnetic nanoparticles are homogeneously distributed onto the GO sheets surface. The enzymatic preparation was immobilized by means of carbodiimide cross-linking chemistry using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide (NHS). The supported final biocatalyst (GO-MNP-Enz) showed high activity for the hydrolysis of pretreated sugarcane bagasse (PSB) and presented relative endoglucanase, xylanase, beta-glucosidase, and beta-xylosidase activities of 70%, 66%, 88%, and 70%, respectively, after 10 cycles of hydrolysis of their respective substrates. The biocatalyst also maintained approximately 50% and 80% of its efficiency for cellulose and xylan hydrolysis, respectively, being the TOF (g.g(-1).h(-1)) the highest observed when compared with previous results reported in literature. These findings suggest that GO-MNP-Enz may be a prospective candidate for industrial applications such as second-generation ethanol production. (C) 2020 Elsevier Ltd. All rights reserved., Sao Paulo State Research Support Foundation (FAPESP) contract number 2018/06241e3 funding this work. Coordination of Improvement of Higher Education Personnel (CAPES) funding the doctoral scholarship of Fernando Roberto Paz-Cedeno in Brazil and in the Universitat Politecnica de Valencia (UPV), Institute of Chemical Technology (ITQ), Valencia, Spain. Authors acknowledge financial support from PGC2018-097277-B-100 (MCIU/AEI/FEDER,UE) project and Severo Ochoa Program (SEV-2016-0683).

The advances in polymer chemistry have allowed the preparation of biomedical polymers using human metabolites as monomers that can hold unique properties beyond the required biodegradability and biocompatibility. Herein, we demonstrate the use of endogenous human metabolites (succinic and dilinoleic acids) as monomeric building blocks to develop a new series of renewable resource-based biodegradable and biocompatible copolyesters. The novel copolyesters were characterized in detail employing several standard techniques, namely 1H NMR, 13C NMR, and FTIR spectroscopy and SEC, followed by an in-depth thermomechanical and surface characterization of their resulting thin films (DSC, TGA, DMTA, tensile tests, AFM, and contact angle measurements). Also, their anti-fungal biofilm properties were assessed via an anti-fungal biofilm assay and the biological properties were evaluated in vitro using relevant human-derived cells (human mesenchymal stem cells and normal human dermal fibroblasts). These novel highly biocompatible polymers are simple and cheap to prepare, and their synthesis can be easily scaled-up. They presented good mechanical, thermal and anti-fungal biofilm properties while also promoting cell attachment and proliferation, outperforming well-known polymers used for biomedical applications (e.g. PVC, PLGA, and PCL). Moreover, they induced morphological changes in the cells, which were dependent on the structural characteristics of the polymers. In addition, the obtained physicochemical and biological properties can be design-tuned by the synthesis of homo- and -copolymers through the selection of the diol moiety (ES, PS, or BS) and by the addition of a co-monomer, DLA. Consequently, the copolyesters presented herein have high application potential as renewable and cost-effective biopolymers for various biomedical applications.

Molybdenum disulfide is a highly esteemed 2D material with interesting applications in nanoelectronics, composites, biotechnology and beyond. Its production through liquid-phase exfoliation in H2O is low-cost and eco-friendly. Herein, we present a detailed experimental and theoretical investigation seeking to explain the peculiar stability of MoS2 in H2O medium. By combining different microscopic (SEM, AFM and OM), spectrometric (Raman, UV-vis and AFM-FTIR), scattering (DLS) and ab initio simulation techniques, an edge-functionalization hypothesis for the excellent solvent properties of water for producing few-layer MoS2 has been demonstrated.

Herein we present a comprehensive study on the role of Bronsted-acidic imidazolium ionic liquids (ILs) and imidazolium salts promoting the reaction between carboxyl and epoxide groups in a controll...

We present the structural modification of a commercially available glass ionomer cement by inserting the imidazolium salt 1-n-hexadecyl-3-methylimidazolium chloride (C(16)MImCl), composing a new biomaterial with antifungal biofilm activity. Test specimens were prepared using a commercial glass ionomer cement to which 10 ppm of cetylpyridinium chloride (reference ionic antifungal agent) or C(16)MImCl were added. The feasibility and hypoallergenicity of the new biomaterial were assessed by microhardness plastic deformation and chorioallantoic membrane assays. Colony counting and scanning electron microscopy were used to evaluate the modified specimens’ antibiofilm activity against three multidrug-resistant Candida species. The modified glass ionomer cement presented a strong antibiofilm activity against Candida spp., without losing its original micromechanical and hypoallergenic properties, rendering it a promising candidate for further application in dentistry.

Conducting polymer hydrogels (CPHs) are an attractive class of materials that synergize the electrical properties of organic semiconductors with the physical properties of hydrogels. Of particular interest is the implementation of CPHs as electrode materials for electrochemical energy storage by taking advantage of redox-tunable conjugated backbones and the large electroactive surface area. Herein, the use of 2D electrolytes as an effective post-polymerization additive to enhance the pseudocapacitive performance of CPHs, is demonstrated. By using the self-doped conjugated polyelectrolyte CPE-K hydrogel as a model system, improvements in cycling stability, specific capacitance and working voltage window upon addition of the 2D electrolytes, are shown. Furthermore, positively charged 2D electrolytes to be more effective than their negatively charged counterparts are revealed. Rheology measurements and SEM imaging indicate that the 2D electrolytes serve as non-covalent cross-linkers that help in forming a mechanically more robust and highly percolated conducting network. These results provide a new and simple to execute post-polymerization strategy to optimize the electrochemical performance of CPH-based pseudocapacitors. National Research Foundation (NRF) This work was supported by the National University of Singapore start up grant R143-000-A97-133 and the Medium-Sized Centre (MSC) grant from the National Research Foundation (NRF) of Singapore, Prime Minister's Office. G.Q. acknowledges funding from the President's Graduate Fellowship (PGF) under the National University of Singapore.

This work describes the solvent-free sol–gel synthesis of epoxy-functionalized silica-based precursors in the presence of 1-butyl-3-methylimidazolium-based ionic liquids (ILs) containing different anions: chloride (Cl–) and methanesulfonate (MeSO3–). The IL-driven sol–gel mechanisms were investigated in detail using experimental characterizations (29Si NMR and ATR FTIR spectroscopy) and a theoretical computational method based on density functional theory (DFT). We observed complex IL influence on both hydrolysis and condensation steps, involving especially H-bonding and Coulomb coupling stabilization of the process intermediates. The obtained IL–silica precursors and their further xerogels were widely characterized (rheology measurements, MALDI TOF, 29Si NMR, ATR FTIR, and DFT simulation), which allowed observation of their precise silica structures and established their most energetically favorable conformations. The detected silica structures were dependent on the IL type and varied from highly condens...

The surface properties of nanofillers and surface/interfacial interactions between fillers and matrix play crucial roles in the control of the properties of composites, especially considering hybrid materials used in biomedical, electronic and energy applications. In the present work, we investigate the surface properties of mono-filler and bi-filler composites of poly (lactic acid) (PLA) with graphene nanoplatelets (GNP) and multi-walled carbon nanotubes (MWCNTs) prepared by melt extrusion method. Zeta potential, contact angle (surface energy), Raman spectroscopy, and atomic force microscopy were used to evaluate the interaction between PLA matrix, GNP and MWCNTs particles, and also to characterize filler-polymer composite properties at the surfaces of the film. The effect of filler loading in the GNP/PLA and GNP/MWCNT/PLA composite films surface properties was investigated using surface Zeta potential by streaming and Contact angle measurements. The results suggest that the surface characteristics of the composite film may be synergistically tuned by incorporation of GNPs and MWCNTs with controlling the filler contents and filler combinations.

Among the biopolymers from animal sources, keratin is one the most abundant, with a major contribution from side stream products from cattle, ovine and poultry industry, offering many opportunities to produce cost-effective and sustainable advanced materials. Although many reviews have discussed the application of keratin in polymer-based biomaterials, little attention has been paid to its potential in association with other polymer matrices. Thus, herein, we present an extensive literature review summarizing keratin’s compatibility with other synthetic, biosynthetic and natural polymers, and its effect on the materials’ final properties in a myriad of applications. First, we revise the historical context of keratin use, describe its structure, chemical toolset and methods of extraction, overview and differentiate keratins obtained from different sources, highlight the main areas where keratin associations have been applied, and describe the possibilities offered by its chemical toolset. Finally, we contextualize keratin’s potential for addressing current issues in materials sciences, focusing on the effect of keratin when associated to other polymers’ matrices from biomedical to engineering applications, and beyond.

Molybdenum disulfide is a highly esteemed 2D material with interesting applications in nanoelectronics, composites, biotechnology and beyond. Its production through liquid-phase exfoliation in H

The assembly of graphene-based materials into nanofibres is of intense technological interest for numerous applications ranging from tissue engineering and drug delivery to fuel cells and space elevators. We demonstrate a composite nanofibre synthesis process using functionalised graphene structures in liquid medium (two-dimensional [2D] electrolytes) as building blocks. The approach consists in simultaneous scrolling and reacting 2D electrolytes, leading to a dimensional reduction of 2D materials into one-dimensional nanostructures. The spontaneous self-assembly and cross-linking processes allow to produce nanofibres without the need of fibrillation techniques, such as wet-spinning or external templates.

A class of compounds sharing the properties of 2D materials and electrolytes, namely 2D electrolytes is described theoretically and demonstrated experimentally. 2D electrolytes dissociate in different solvents, such as water, and become electrically charged. The chemical and physical properties of these compounds can be controlled by external factors, such as pH, temperature, electric permittivity of the medium, and ionic concentration. 2D electrolytes, in analogy with polyelectrolytes, present reversible morphological transitions from 2D to 1D, as a function of pH, due to the interplay of the elastic and Coulomb energies. Since these materials show stimuli-responsive behavior to the environmental conditions, 2D electrolytes can be considered as a novel class of smart materials that expand the functionalities of 2D materials and are promising for applications that require stimuli-responsive demeanor, such as drug delivery, artificial muscles, and energy storage.

Herein, we demonstrate the effect of imidazolium ionic liquids (IL) applied as additives in the in situ formation of high amorphous vinyl alcohol (HAVOH)-silica bionanocomposites, using a simple sol-gel process approach. A complementary set of alkyl-, ether-, and carboxy-functionalized IL was used, allowing silica structure control and polymer-silica interphase tuning. Consequently, hybrids with diverse morphologies, as well as improved thermo-mechanical and barrier properties, were obtained. This diversity also highlighted the systems' dependency on the IL's molecular structure, where both the cation and anion influenced the hybrids' final properties. This could be evidenced as the polar group functionalized-IL (ether- and carboxy-functionalized IL) allowed the formation of multiple hydrogen bonds at the organic-inorganic interphase, inducing a fine hybrid morphology with well-dispersed silica nanodomains. This significantly increased the storage (~50%) and tensile moduli (~20%), extensibility (up to 300%), and glass transition temperature (>20 °C) and decreased the water vapor permeability (~50%), which are desirable characteristics for potential food and medical packaging.

Aims This study demonstrates the development of a mouthwash formulation containing the imidazolium salt (IMS) 1-n-hexadecyl-3-methylimidazolium chloride (C16MImCl), considering its stability and efficacy against Candida sp. Biofilm formation. Methods and Results A variety of in vitro test methods were applied, assessing contaminated acrylic resin strip specimens before and after applying the mouthwash formulations. The formulation using C16MImCl presented a similar antibiofilm activity to cetylpyridinium chloride one and a commercial mouthwash, but at a 10 times lower concentration. Scanning electron microscopy imaging demonstrated that the selected mouthwash preparation fully destroys the biofilm cells, while with the hypoallergenicity test no irritant effect was observed in ex vivo model. Conclusions The results presented herein indicate a high potential for imidazolium salts application as mouthwash agents that can eliminate Candida biofilm growth at very low concentrations. Significance and Impact of the Study This study demonstrates a new and effective antibiofilm formulation containing the IMS C16MImCl. These findings suggest the IMS’ use as mouthwash formulations active ingredient against Candida biofilms on oral surfaces, as it outperforms the often used cetylpyridinium chloride at a 10 times lower concentration.

This work describes the preparation of bio-based thermoplastic poly(ether-urethane)s (TPU) via a prepolymer method and investigates the effect of varying the interphase hydrogen-bonding (H-bonding) on physicochemical, thermal and mechanical properties. This was achieved by varying the glycol type and molar ratio of [NCO]/[OH] groups used during the prepolymer chain extending step. The TPUs’ chemical structure was analyzed by Fourier Transform Infrared Spectroscopy (FTIR-ATR) spectroscopy, the H-bonding fraction and crystallinity were examined by FTIR, Different Scanning Calorimetry (DSC), X-ray diffraction (XRD) and Polarized light optical microscopy (POM), and their processability was surveyed using the melt-flow index and Matrix-Assisted Laser Desorption/Ionization-Time of Flight Mass Spectrometry (MALDI-TOF-MS). Moreover, a coupled- Thermogravimetric analysis (TGA)-FTIR method provided useful information about thermal degradation and low molecular mass volatile products formed during the TPUs’ thermal decomposition. Altogether, this study intends to provide engineers with new insights to obtain environmentally friendly TPU-based polymeric components (from prime materials to process methods), by associating the application of bio-based reactants to the TPU synthesis and understanding the conditions for these bio-TPUs been applied in low-waste processes such as additive manufacturing.

Herein we describe a successful protocol for graphite exfoliation using a biphasic liquid system (water/dichloromethane, DCM) containing ionic liquids (ILs; 1,3-dibenzylimidazolium benzoate- and 1-naphthoate). The use of (surface active) IL and sonication led to stable DCM/water (O/W) emulsion, which enhanced graphene formation, suppressed its re-aggregation and decreased shear/cavitation damage. The O/W emulsion stabilization by the ILs was studied by dynamic light scattering (DLS), whereas their interaction with the graphene sheets were described by Density Functional Theory (DFT) calculations. Moreover, a comprehensive investigation on cavitation-based exfoliation in the O/W systems was performed to assess the importance of operational parameters, including, the type of ultrasound processor, ultrasound power and insonation, and the influence of the exfoliation medium.

High performance shape memory (SM) epoxy–silica nanocomposites have been synthesized. The structure of the corresponding SM polymer was designed on the basis of the determined relationships between structure, mechanical properties and SM performance. The recovery stress, as a crucial SM property of high performance systems, is governed by the material toughness while the efficiency of the SM performance is controlled by morphological homogeneity and viscoelastic behaviour of the polymer as well as by experimental conditions of the SM procedure. The nanocomposites were prepared by in situ generation of nanosilica in the epoxy matrix. A non-aqueous sol–gel procedure was applied and the ionic liquid (IL) was used in the synthesis as a multifunctional agent controlling morphology and mechanical properties. The effect of nanosilica, IL, crosslinking density of the epoxy network, physical crosslinking as well as the application of the concept of bimodal networks on SM performance was evaluated and discussed. Based on the knowledge of the corresponding relationships and structural effects the SM nanocomposite was synthesized showing the high recovery stress σr = 3.9 MPa or high deformability eb = 103%. The study contributed to the better understanding of the SM behaviour of polymers.

The study reported herein describes for the first time a method for producing defect-free graphene directly from its mineral ore. This was achieved by treating graphite ore in an ionic liquid containing biphasic solvent system, applying pressurized intense cavitation ultrasound. Without any graphite ore pre-treatment, large few layer thick graphene sheets, as well as micrometric layered crumpled graphene structures, were produced. This opens new opportunities for the development of graphene-based technologies.

UNLABELLED Although the use of catheters in critically ill patients is mostly inevitable, this invasive procedure comes together with several health risks. Within this context, the contamination with Candida tropicalis is a primary concern as this highly prevalent pathogenic yeast can develop an extensive polymeric matrix that hinders the drugs' penetration and its effective treatment. This study addresses the potential for the 1-n-hexadecyl-3-methylimidazolium methanesulfonate (C16 MImMeS) and chloride (C16 MImCl) salts for eliminating the viable cells of biofilms of Candida tropicalis, compared to the performance of chlorhexidine (CHX) and fluconazole (FLZ). The minimum concentration required of C16 MImMeS, C16 MImCl, CHX and FLZ for elimination of the biofilm's viable cells (MBEC) was evaluated through microtitre plate biofilm exposure with different concentrations of these substances. These concentrations were determined at 80% of effective activity against the biofilm's viable cells by using the MTT reduction assay. C16 MImMeS and C16 MImCl were able to eliminate the viable cells at much lower concentrations (15·6 and 0·45 μg ml(-1) respectively) than CHX (1250 μg ml(-1) ) and FLZ (resistance of the viable cells). This demonstrates the high potential of these substances for nosocomial infections control. SIGNIFICANCE AND IMPACT OF THE STUDY The 1-n-hexadecyl-3-methylimidazolium methanesulfonate (C16 MImMeS) and chloride (C16 MImCl) salts are extremely effective in eliminating the viable cells of Candida tropicalis biofilms, which allows the use of much lower concentrations than with the antimicrobial of choice (chlorhexidine) in hospital practices. These findings indicate these imidazolium salts as high-potential candidates for asepsis of medical environments and materials, including implants.

This work presents a detailed investigation about the influence of a complementary set of imidazolium ionic liquids (IL: [C4MIm][BF4]-[C10MIm][BF4]-[C7O3MIm][BF4]-[C4MIm][NTf2]-[C10MIm][NTf2]-[C7O3MIm][NTf2]) in the preparation of hydrolytic sol-gel silica wet gels and xerogels, providing insights into their hierarchical structures, morphologies of primary particles and aggregation domains. The reported IL decreased dramatically the gelation time (up to ~500 times), evolving the systems to transparent or opalescent wet gels with distinct consistencies, or silica powders. Characterization of the obtained silica xerogels was performed by transmission and scanning electron microscopy, atomic force microscopy, X-ray diffraction, small-angle X-ray scattering and thermogravimetric analysis. In general, the IL allowed controlling the silica particle size, color, compactness, structures and morphology. The xerogels showed homogenous and ordered structures (spherical or triangular) of different sizes and with distinct microporosities, depending on the IL applied. These results highlight the key role of IL in the sol-gel silica synthesis with controlled properties, which can be further tuned for specific applications by changing small process parameters. Graphical Abstract: [Figure not available: see fulltext.]

Carboxylic-functionalized task-specific imidazolium ionic liquids (carboxylic-ILs) presented selective high reactivities with epoxy-functionalized compounds, even in highly complex epoxy–silica nanocomposite systems. The carboxylic-ILs induced the in situ covalent bonding with epoxy based materials and tuning of the nanocomposites’ filler–matrix interphase when applied either via hydrolytic or non-hydrolytic sol–gel processes. Structural modifications in the carboxylic-ILs allowed fine morphology control and promoted the formation of well dispersed silica nanodomains. This approach resulted in nanocomposites with improved mechanical properties, without a negative effect on the glass transition temperature, for both rubbery and glassy epoxy–silica nanocomposite systems with a very small IL content (∼0.2 wt%). The best properties were achieved with the application of IL 1-carboxypropyl-3-methylimidazolium chloride, which produced a toughness increase of more than 7 times for the rubbery and almost twice for the glassy epoxy systems, when compared to their IL-free equivalents. These easy and quick procedures to produce imidazolium functionalized materials have the potential to open up a broad range of new conductive, responsive, smart and tunable reinforced materials.

The in vitro activity of the imidazolium salt C16MImCl against planktonic and biofilm cells of multidrug-resistant isolates of Candida tropicalis was evaluated, both in solution and applied on a commercial catheter surface. This was determined by inhibition and susceptibility assays of biofilm and planktonic cells. In both cases, C16MImCl prevented in vitro biofilm formation of C. tropicalis strains, including multidrug-resistant ones. Outstanding performances were observed, even at extremely low concentrations. Furthermore, this is the first report of the antifungal lock property of C16MImCl, using a tracheal catheter as the test specimen to mimic a clinical in vivo condition. As such, C16MImCl has been identified as a promising antimicotic pharmaceutical candidate for the treatment of candidiasis infections. Significance and Impact of the Study The imidazolium salt 1-n-hexadecyl-3-methylimidazolium chloride (C16MImCl) strongly prevents, in concentrations as low as 0·028 μg ml−1, the biofilm formation of multidrug-resistant Candida tropicalis isolates, either in solution or applied on the surface of commercial catheters. This presents an effective antimicotic candidate and alternative for invasive clinical procedure toolset asepsis.

This work describes a straightforward procedure for the preparation of graphene by opening multi-walled carbon nanotubes (CNT), using ionic liquids (IL) as lubricating and stabilizing agents. The sequential application of vacuum and sonication allows the successful opening and unrolling of the CNT, and the final nanocarbon morphology is IL-dependent. This enabled the preparation of epoxy-based nanocomposites with morphologically distinct carbon nanofillers. The CNT–IL mixtures and nanocomposites obtained were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), atomic force microscopy (AFM) and Raman spectroscopy.

Biofilms provide an ideal environment for protecting the microbial cells from damage caused by humoral and cellular immune system components, promoting resistance, infections and increasing mortality and morbidity of patients in health facilities. In an attempt to provide an innovative solution for preventing contamination in hospital environments, this study evaluated nine structural complementary fluorescent benzimidazo[1, 2-α]quinolines as bifunctional agents that both detect and have biocidal activity against yeast biofilms on stainless steel surfaces. The benzimidazoles’ staining capability was determined by a fluorescence microscopy study and spraying the substance on yeast biofilm contaminated stainless steel surfaces. Furthermore, their in vitro human leukocyte cytotoxicity was evaluated with trypan blue and their biocidal activity was determined as the minimum inhibitory concentration against Candida tropicalis, C. albicans and C. parapsilosis strains. Moreover, scanning electron micrographs were recorded to study the biocidal activity. This resulted in the identification of 7, which presents all the desired characteristics (such as solubility) and capabilities (staining and biocide activity against all tested biofilm forming yeast strains) at the same time. As such, benzimidazole 7 has the potential to guarantee the use of disinfected medical and surgical instruments in clinical and surgical procedures, consequently, contributing to an increased safety for patients.

In this research, the oleate-functionalized magnesium and aluminum layered double hydroxide (LDH; Mg:Al = 3:1) o-LDH was applied as nanofiller in the melt blending of polypropylene (PP) nanocomposites, in order to understand its role in this process. o-LDH was prepared using the memory effect of the calcined carbonated LDH. Blending of PP and low o-LDH filler contents of 0.45 and 0.90 wt.% afforded the nanocomposites PP0.45 and PP0.90, respectively, which were characterized by transmission electron microscopy, X-ray diffraction, small angle X-ray scattering, thermo-gravimetric analysis, differential scanning calorimetry and dynamic mechanical analysis. The oleate LDH surface functionalization enhanced the system compatibility as a relative regular dispersion of o-LDH tactoids was observed within the matrix, together with partial PP intercalation. This o-LDH incorporation increased the PP relative crystallinity, induced crystalline orientation and decreased the glass transition temperature. Furthermore, the nanocomposites showed improved initial resistance to decomposition and stiffness. These results showed that the o-LDH acted as both nucleating agent and plasticizer, and that the presented approach can be used for the development of PP nanocomposites with distinguished properties.

This article describes the preparation of silica xerogels by the sol–gel technique, using tetraethoxysilane as precursor and hydrofluoric acid as catalyst, in the presence of imidazolium ionic liquids (ILs). The applied ILs 1–3 contained the 1-monoethylene glycol monomethyl ether-3-methylimidazolium cation in combination with the methanesulfonate (1), tetrafluoroborate (2) and hexafluorophosphate (3) anions, respectively. Characterization of these materials was performed by photography, scanning electron microscopy, atomic force microscopy, X-ray diffraction, thermogravimetric analysis and nitrogen adsorption-desorption isotherms. The IL anion was identified as a powerful morphology controller. The methanesulfonate anion of IL 1 induced the formation of a compact lamellar monolith with an interlamellar distance of 1.5 nm and a flat surface. A free flowing powder of aggregated spherical particles was obtained in the presence of tetrafluoroborate IL 2, and the hexafluorophosphate anion of IL 3 induced the formation of porcelain like aggregates with honeycomb shapes.

This article describes the preparation of xerogel silica’s by the sol–gel technique in the presence of the ionic liquids (ILs) 1-triethylene glycol monomethyl ether-3-methylimidazolium methanesulfonate 1 and 1-monoethylene glycol monomethyl ether-3-methylimidazolium methanesulfonate 2, using tetraethoxysilane as precursor. The addition of water to these ILs resulted in the formation of protonic acid. As a consequence, the ILs functioned as morphology controller and acid pre-catalyst at the same time. Characterization of these materials was performed by photography, scanning electron microscopy, thermogravimetric analysis and powder X-ray diffraction. Compact lamellar monoliths with interlamellar distances of approximately 1.5 nm and flat surfaces were obtained with both ILs.

Cyclic voltammetry measurements using a platinum electrode were performed to study the effect of water when added to the imidazolium room-temperature ionic liquids (RTILs) 1 [C7O3MIm][Mes] and 2 [C3O1MIm][Mes]. The addition of a very small amount of water to RTIL 1 resulted in diminished cathodic current values. An even more pronounced effect was observed with RTIL 2 and all charge transfer processes were extremely reduced. This inhibition of the charge transfer processes suggests the formation of new species, due to a reaction between water and the RTILs, that adsorbs on the electrode surface.

The electrochemical behavior of a platinum electrode in a set of 1-alkyl ether (and 1-alkyl)-3-methylimidazolium room-temperature ionic liquids (RTILs) 1–3 ([CxOyMim]+[Anion]− or [CxMim]+[Anion]−, where Mim = 3-methylimidazolium; CxOy = 1-alkyl ether; C7O3 = -(CH2)2O(CH2)2O(CH2)2OCH3; C3O1 = -(CH2)2OCH3; Cx = 1-alkyl; C10 = C10H21; C4 = C4H9; and \( {\left[ {{\text{Anion}}} \right]}^{ - } = {\text{H}}_{3} {\text{CSO}}^{ - }_{3} ,{\text{ BF}}^{ - }_{4} {\text{, or PF}}^{ - }_{6} \)) was studied by cyclic voltammetry and electrical conductivity. This complementary set of imidazolium RTILs allowed us to explore the effect of the imidazolium cation and the counter-ion, both of which affected the electrochemical window of these RTILs. Various electrochemical events with low current values were observed, which diminished the electrochemical windows. Interestingly, RTILs 2b [1-(2-methoxyethyl)-3-methylimidazolium tetrafluoroborate] and 2d [1-butyl-3-methylimidazolium tetrafluoroborate] showed quasireversible charge transfer processes. The length of the functional group attached to the imidazolium cation was shown to be of great influence as larger electrochemical windows, as well as lower electrical conductivities, were obtained with the longer C7O3 and C10 functional groups. The largest electrochemical window of 2.0 V was achieved with RTIL 2c, 1-decyl-3-methylimidazolium tetrafluoroborate.

AIMS Evaluate the in vitro effect of imidazolium salts (IMS) on the conidia germination and mycelial growth of Fusarium graminearum and their in vivo efficacy for suppressing the symptoms of the disease and infection of kernels in wheat plants. METHODS AND RESULTS The minimum inhibitory concentrations (MIC) of three IMS (C16 MImCl, C16 MImMeS and C16 MImNTf2 ) were determined for four F. graminearum isolates using serial broth dilution method. The MICs found for all IMS were either 3·12 or 6·25 μg ml(-1) across the isolates, with the former as the most frequent. In the mycelial growth assay on potato dextrose agar media, only the C16 MImCl among the IMS reduced 50% of mycelial growth of one isolate at an estimated concentration of 0·32 mg ml(-1) . The time-kill curves showed a strong fungicidal effect starting 1 h after incubation at a concentration of 12·5 μg ml(-1) , representing a fourfold increase in the most frequent MIC. The C16 MImCl sprayed onto the spikes of potted wheat plants during the flowering stage reduced disease intensity at levels comparable to the commercial fungicide when applied preventatively (1 h prior to fungal inoculation), rather than curatively, and at the higher dosage (2 mg ml(-1) ) rather than lower dosage (0·5 mg ml(-1) ). CONCLUSIONS C16 MImCl proved to be a potent inhibitor of F. graminearum growth and provided good levels of control of the disease at levels comparable to a commercial fungicide, in wheat plants treated prior to fungal infection during flowering stages. SIGNIFICANCE AND IMPACT OF THE STUDY This study suggests the potential of using IMS as alternative to the hazardous standard fungicides in the management of Fusarium head blight of wheat.

Aims To investigate the antidermatophytic action of a complementary set imidazolium salts (IMS), determining structure-activity relationships and characterizing the IMS toxicological profiles. Methods and Results The susceptibility evaluation of 45 dermatophytic clinical isolates, treated in vitro with eleven different IMS (ionic compounds) and commercial antifungals (nonionic compounds), was performed by broth microdilution, following the standard norm of CLSI M38-A2. All dermatophytes were inhibited by IMS, where the lowest minimum inhibitory concentration (MIC) values were observed for salts with n-hexadecyl segment in the cation side chain, containing either the chloride or methanesulfonate anion. 1-n-Hexadecyl-3-methylimidazolium chloride (C16MImCl) and 1-n-hexadecyl-3-methylimidazolium methanesulfonate (C16MImMeS) acted as fungicides, even in extremely low concentrations, wherein C16MImMeS exerted this effect on 100% of the tested dermatophytes. Some of these IMS provoked evident alterations on the fungi cell morphology, causing a total cell damage of ≥70%. Importantly, none of the screened IMS were cytotoxic, mutagenic or genotoxic to human leucocyte cells. Conclusions This report demonstrates for the first time the strong antifungal potential of IMS against multidrug-resistant dermatophytes, without presenting toxicity to human leucocyte cells at MIC. Significance and Impact of the Study The expressive antifungal activity of IMS, combined with the in vitro nontoxicity, makes them promising compounds for the safe and effective treatment of dermatophytoses, mainly when this skin mycosis is unresponsive to conventional drugs.

Herein, we present the intrinsic property of well-known polyesters [poly(alkene succinates)], as Candida albicans and Candida tropicalis biofilm inhibitors with potential to substantially reduce the incidence of device-associated infections in, e.g., indwelling catheters and sutures. These new biopolymer applications, either for manufacturing or coating medical devices, present innovative features such as: simple and cheap preparation, easy scaling-up, good mechanical and thermal resistance properties, and antibiofilm ability without any specific surface functionalization or antimicrobial agent encapsulation. Furthermore, the polyesters are shown to be highly biocompatible, promote human mesenchymal stem cell (hMSC) attachment and proliferation, inducing morphological changes, which are dependent on the polymer structural characteristics, making them promising candidates for materials in specialized medical devices and in the tissue engineering field.

The ether-functionalized imidazolium ionic liquids (IL) applied in the silica sol-gel process demonstrated a defined coordination potential. These IL display the capacity to control the system organization from the reactions' first moments through a dynamic system-assembling ability, being the sum of ionic and physical interactions, i.e. Coulomb forces, H-bonding and London forces. The initial hydrolysis steps of tetraethyl orthosilicate (TEOS) in the presence of these IL were followed by Fourier transform infrared spectroscopy (FTIR) and dynamic light scattering (DLS), both in time-resolved experiments, in an attempt to correlate the structuring and the bonding dynamics of these systems.

Compósitos de poliestireno com 1, 3 e 5% em massa de argila aniônica funcionalizada com cinamato foram preparados no estado fundido em extrusora de rosca dupla co-rotacional seguido de moldagem por injeção, a fim de se obter materiais com propriedades diferenciadas e absorvedores de radiação UV, utilizando processos comumente disponíveis industrialmente. A caracterização dos compósitos realizou-se através das técnicas de DRX, MET, TG, DSC, UV-Vis, SAXS e ensaios mecânicos diversos (tração, impacto, flexão e dureza). O aumento da distância interlamelar da argila após o processamento indicou a intercalação do poliestireno. Um baixo grau de dispersão de argila foi alcançado e os compósitos de poliestireno se constituíram de fases intercaladas e microtactóides. Em geral, os compósitos apresentaram propriedades mecânicas (tração, flexão, impacto Izod e dureza) similares ao poliestireno puro. Entretanto, os mesmos são capazes de absorver a radiação UV, o que aumentou proporcionalmente ao teor de argila, e, desta forma, apresentam potencial para utilização como filtros de radiações nocivas. Polystyrene composites with 1, 3 and 5% in weight of cinnamate-functionalized anionic clay were prepared following a melt state intercalation route using twin-screw co-rotational extrusion followed by injection molding in order to obtain materials with distinct and UV absorbing properties using commonly available processes. The composites were characterized by XRD, MET, TG, DSC, UV-Vis, SAXS and mechanical testing (tensile, impact, flexural and hardness). The interlamellar distance of the clay galleries increased after melt blending as a result of polystyrene intercalation. A moderate degree of clay dispersion was achieved and the polystyrene composites comprised intercalated phases and clay microtactoids. The composites showed mechanical properties generally similar to neat polystyrene. Nevertheless, the polystryrene composites were able absorbing UV light, which increased with increasing clay-content, and showed potential use as filter against this harmful radiation.

This article describes the application of ionic liquid 1-decyl-3-methylimidazolium tetrafluoroborate in the preparation of polypropylene-silica composites. The sol-gel technology was used to prepare xerogel silica-ionic liquid hybrid S1, which was obtained as a free flowing powder of aggregated spherical particles. Ionic liquid free silica S2 was obtained by extraction and calcination of S1. Melt blending of isotactic polypropylene with S1 and S2 afforded the composites C1 (with ionic liquid) and C2 (without ionic liquid), respectively. The presence of ionic liquid on the S1 silica surface promoted significantly improved silica dispersion in the polymer matrix and prevented compression of the silica particles. Furthermore, the crystallization temperature of composite C1 was significantly higher, which indicated that silica-ionic liquid filler S1 acted as nucleating agent. The resistance to thermal decomposition of both composites was increased, but this was higher in the presence of ionic liquid. These results show that liquid salts can function as coupling agents and compatibalizers for the preparation of polymeric composites with differentiated properties. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

Correction for ‘Tailored high performance shape memory epoxy–silica nanocomposites. Structure design’ by S. Ponyrko, et al., Polym. Chem., 2016, 7, 560–572.

The Sonogashira cross-coupling reaction of vinylic and heteroaromatic tellurium dichlorides has been explored, yielding the corresponding enynes and 2-alkynyl substituted heteroaromatic compounds. The reaction was carried out with PdCl2/CuI as catalysts and triethylamine as base, using methanol as solvent. The reaction proceeded under mild conditions and the cross-coupled products were obtained in good yields and in a stereoconservative manner.

Imidazolium ionic liquids (ILs) have the capacity to exert multiple functions as additives for the formation of epoxy-silica nanocomposites, via the simultaneous sol–gel process and epoxy network build-up. This study addresses the effect of ILs on the reinforcement of tensile properties in rubbery epoxy-silica nanocomposites, allowing property tailoring. The use of ILs together with the coupling agent 3-glycidyloxypropyltrimethoxysilane (GTMS) created a synergic action between physical and chemical interfacial bonding, enabling an increase in toughness without a considerable loss of stiffness. The best tensile property balance was obtained with IL 1-triethylene glycol monomethyl ether-3-methylimidazolium methanesulfonate and GTMS. The rubbery nanocomposite produced was remarkably both stiffer and tougher than the unmodified epoxy-silica system, displaying ca. 6 times higher modulus and tensile strength as well as more than 10 times higher energy to break.

In this work, we designed and studied two synthetic routes, based on modified Hummers method, to obtain graphene oxide (GO), and investigated their influence on the performance of polypropylene (PP)/GO nanocomposites. The two synthetic routes differed in the application condition of the oxidizing agent, potassium permanganate (KMnO4), which was added either as a powder (GO-P) or as a water solution (GO-S). This apparently subtle synthetic change yielded GOs with different degrees of oxidation and particle sizes, where GO-P presented a higher oxidation degree and smaller particles. The different GOs were then melt-blended with PP and the correlation between their different chemical/morphological structures and the nanocomposites' thermomechanical/rheological properties were evaluated. The milder oxidation process suffered by GO-S, and consequent less hydrophilic character, yielded a PP/GO-S nanocomposite with improved performance as the consequence of a better matrix/filler chemical affinity, mainly in compositions with lower GO-S contents. The thermal stability was increased by more than 10°C when 0.1 wt% GO-S was inserted into PP. When compared to the composition with 0.1 wt% GO-P, the increase was 13°C. Reinforcing effects were also observed in that sample (with 0.1 wt% GO-S), which exhibited the highest storage modulus and complex viscosity. These results suggest that tailoring the GO's oxidation degree and morphology is a key point to obtain an ideal interfacial interaction between phases.