Environmentally friendly carrageenan-based ionic-liquid driven soft actuators

UID/FIS/04650/2020 UID/QUI/0686/2020 LA/P/0008/2020 PID2019-106099RB-C43/AEI/10.13039/501100011033A naturally derived polymer based on iota carrageenan and different ammonium and imidazolium based ionic liquids (ILs) are used for the development of environmentally friendly soft actuators. The influence of IL content and type and solvent evaporation temperature on the morphological and physico-chemical properties of the materials was evaluated, together with the effect on actuator functional response. Independently of the IL content and type, and the solvent evaporation temperature, a non-porous structure is obtained. The incorporation of the IL within the polymer matrix does not affect the thermal stability but leads to a decrease in the Young modulus for the different IL/carrageenan samples. The highest influence was observed by using the [Ch][DHP] IL at a filler content of 40% w/w with a decrease in the Young modulus from 748 MPa for the neat polymer to 145 MPa for the [Ch][DHP]/carrageenan sample. Furthermore, the ionic conductivity of the samples increases with increasing IL content, with the highest values being 2.9 × 10-6 S cm-1 and 1.2 × 10-6 S cm-1 for the samples with 40% w/w of [Bmim][FeCl4] and [Ch][DHP], respectively. Regarding the soft actuator performance, the maximum displacement was obtained for the [Ch][DHP]/carrageenan sample with an IL content of 40% w/w, showing a maximum displacement of 5.8 mm at a DC applied voltage of 9 V.publishersversionpublishe

Functional properties of coatings based on novel waterborne polyurethane dispersions with green cosolvents

Three green sustainable cosolvents were used to produce polyurethane waterborne coatings. The effect of dihydrolevoglucosenone, gamma valerolactone and propylene carbonate on the performance of different coatings from a range of polyurethane structures with different hard segment content and different chain extender (a diol and a diamine) was studied. Properties of both synthesised polymers and water dispersions, like particle size distribution, stability, and pH, were carefully examined. The key properties of obtained coatings, including Koning hardness, specular gloss, hydrophobicity, abrasion resistance, adhesion or chemical resistance were detailly investigated to validate the use of these alternative green solvents in industrial coatings. The results indicated that the performance of materials based on sustainable cosolvents were equivalent to that of PUD coatings from commonly used cosolvent, N-methyl-2-pyrrolidone (NMP) maintaining a high gloss finished, as the properties of the dispersions keep optimal. Monomodal water dispersions with particle's diameter below 180 nm and stable for at least one month were achieved.This work was financially supported by Frontiers project Elkartek Programme from Basque Country Government and the biobased In- dustries Undertaking (JU) under the European Union's Horizon 2020 research and innovation programme under VIPRISCAR project grant agreement No 790440. The JU receives support from the European Union's Horizon 2020 research and innovation programme and the Bio Based Industries Consortium

Lignin-Based Hydrogels: Synthesis and Applications

Polymers obtained from biomass are an interesting alternative to petro-based polymers due to their low cost of production, biocompatibility, and biodegradability. This is the case of lignin, which is the second most abundant biopolymer in plants. As a consequence, the exploitation of lignin for the production of new materials with improved properties is currently considered as one of the main challenging issues, especially for the paper industry. Regarding its chemical structure, lignin is a crosslinked polymer that contains many functional hydrophilic and active groups, such as hydroxyls, carbonyls and methoxyls, which provides a great potential to be employed in the synthesis of biodegradable hydrogels, materials that are recognized for their interesting applicability in biomedicine, soil and water treatment, and agriculture, among others. This work describes the main methods for the preparation of lignin-based hydrogels reported in the last years, based on the chemical and/or physical interaction with polymers widely used in hydrogels formulations. Furthermore, herein are also reviewed the current applications of lignin hydrogels as stimuli-responsive materials, flexible supercapacitors, and wearable electronics for biomedical and water remediation applications

Tuning magnetic response and ionic conductivity of electrospun hybrid membranes for tissue regeneration strategies

Electrospun membranes play an increasing role in tissue regeneration base on their suitable morphological features. The implementation of active response, such as magnetically responsiveness or piezo-ionic features can further improve tissue regeneration by better resembling varying microenvironment during cell culture. In this context, this work reports on the development of poly(vinylidene fluoride) (PVDF) oriented (O) and randomly (R) oriented electrospun fibers containing different amounts of iron oxide nanoparticles (Fe3O4, NP) or ionic liquid (IL) choline bis(trifluoromethylsulfonyl) imide ([Chol][TFSI]) (5, 10 and 15% wt.). The addition of the fillers did not result in significant differences in the morphology of the electrospun fibers or their degradation temperature. PVDF-O+IL fibers present diameters between 0.98 and 1.28 µm, crystallinity between 52 and 59% and electroactive PVDF β-phase content between 73 and 88%. PVDF-R + IL fiber diameter ranges from 1.29 to 1.97 µm, crystallinity between 46 and 55% and β-phase content between 79-82%. The PVDF-O+Fe3O4 fiber diameter varied between 0.81 and 1.07 µm, crystallinity between 48 and 59% and β-phase between 73 and 81%. The effective NP content in the fibers followed a nearly-linear relation with the theoretical values, with experimental yields between 93-97%. Further, the inclusion of IL into PVDF matrix leads to an increase of the ionic conductivity up to 2.6×10-9 S.cm-1 for the sample with 15% IL content. Finally, the potential of the materials for tissue engineering was evaluated, by analyzing its cytotoxicity for L929 fibroblasts, with cell viability results of over 90% indicating the cytocompatibility of these materialsThis work was supported by the Spanish State Research Agency (AEI) and the European Regional Development Fund (ERFD) through the project PID2019-106099RB-C43/AEI/10.13039/501100011033. Financial support from the Basque Government Industry and Education departments under the ELKARTEK and PIBA (PIBA-2018-06) programs, respectively, is also acknowledged. The authors acknowledge funding by the Fundação para a Ciência e Tecnologia (FCT) and by ERDF through COMPETE2020 - Programa Operacional Competitividade e Internacionalização (POCI) in the framework of the Strategic Programs UID/FIS/04650/2020 and project PTDC/BTM-MAT/28237/2017. Also, the authors thank FCT for the research grant SFRH/BPD/121526/2016 (DMC), and CR thanks the FCT for the contract under the Stimulus of Scientific Employment (2020.04163.CEECIND)

Photocatalytic and antimicrobial multifunctional nanocomposite membranes for emerging pollutants water treatment applications

Supplementary data to this article can be found online at https://doi.org/10.1016/j.chemosphere.2020.126299.Emerging pollutants represent a new global problem for water quality. As these compounds get into the environment, they cause severe threats to aquatic environments and human health and are typically resistant to conventional wastewater treatments. In this work, TiO2 nanoparticles surface was functionalized with silver (Ag) nanoparticles, and solvent cast and electrospun membranes of poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) were prepared with different concentrations of TiO2 and AgTiO2 to produce a multifunctional material. The photocatalytic activity of the nanocomposites was evaluated through the degradation of norfloxacin under ultraviolet (UV) and visible radiation. It is shown that nanocomposites with AgTiO2 show the highest degradation efficiencies: 64.2% under UV and 80.7% under visible radiation, for 90 and 300 min, respectively. Furthermore, the recyclability of the membranes has also been demonstrated. Finally, it is shown the antimicrobial activity of the nanocomposite membranes, demonstrating the suitability of the AgTiO2/PVDF-HFP nanocomposites as multifunctional photocatalytic and antimicrobial membranes for water remediation applications.This work was supported by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Projects PEST-C/FIS/UI607/2019 and PEST-C/QUI/UIO686/2019 and projects PTDC/BTM-MAT/28237/2017; PTDC/EMD-EMD/28159/2017 and PTDC/FIS-MAC/28157/2017. H. Salazar thanks the FCT for grants SFRH/BD/122373/2016. M. M. Fernandes thanks the FCT grant SFRH/BPD/121464/2016. Financial support from the Spanish Ministry of Economy and Competitiveness (MINECO) through project MAT 2016-76039-C4-3-R (AEI/FEDER, UE) (including FEDER financial support) and from the Basque Government Industry and Education Departments under the ELKARTEK, HAZITEK and PIBA (PIBA-2018-06) programs, respectively, are also acknowledged.info:eu-repo/semantics/publishedVersio

Metal organic framework based PVDF separators for high rate cycling lithium-ion batteries

Poly(vinylidene fluoride) (PVDF) and MOF-808-based separators for lithium-ion batteries (LIBs) have been prepared and fully characterized in terms of morphological and thermal properties, electrolyte uptake, and retention, and surface hydrophilic characteristics. The effect of PVDF/MOF-808 separators on the electrochemical performance of LIBs has been evaluated. The PVDF/MOF-808 membranes exhibit a well-defined porous structure with a uniform distribution of interconnected macro- to mesopores. The inclusion of the Zr-based MOF nanoparticles increases the porosity and surface area of the separator, enhancing the electrolyte uptake and the ionic conductivity. Finally, the presence of MOF-808 fillers improves the liquid electrolyte retention, which prevents the capacity fading at high C-rates cycling. Indeed, charge–discharge tests performed in Li/C-LiFePO4 half-cells reveal a discharge capacity of 68 mAh·.g–1 at 2C-rate for PVDF/MOF-808 membranes, in comparison with the 0 mAh·g–1 obtained for pure PVDF. The PVDF/10 wt % MOF-808 sample shows a long-term stable cycling behavior with a Coulombic efficiency close to 100%. Thus, it is shown that the composite membranes represent an improvement with respect to conventional separators for lithium ion battery applications, since they coupled the polymer meso- and macroporous structure with the well-ordered microporous system of the MOFs, which improve significantly the electrolyte affinityFCT (Fundação para a Ciência e Tecnologia) for financial support under the framework of Strategic Funding grants UID/FIS/04650/2019, and UID/QUI/0686/2019 and project PTDC/FIS-MAC/28157/2017. The author also thanks the FCT for financial support under grant SFRH/BPD/112547/2015 (C.M.C.) and Investigator FCT contract CEECIND/00833/2017 (R.G.). A.V. thanks to the Basque Government Education department for her pre-doctoral grant. The European Commission Research & Innovation H2020-MSCA-RISE-2017 (Ref.: 778412) INDESMOF project is also acknowledged. Financial support from the Basque Government Industry and Education Departments under the ELKARTEK (ACTIMAT and LION), HAZITEK (SIMAM) and PIBA (PIBA-2018-06- LIMOFILM)

Ionic liquid modified electroactive polymer-based microenvironments for tissue engineering

The combination of electroactive polymers and ionic liquids (ILs) has been gaining much attention for tissue engineering. Thus, this work reports on the development of oriented electrospun fibers and films based on poly(vinylidene fluoride) (PVDF) and polyhydroxybutyrate-co-hydroxyvalerate (PHBV) blended with the IL choline acetate ([Chol][Ac]). The inclusion of IL into the polymer matrix induces a decrease in the fiber orientation, particularly for PHBV + IL electrospun fibers. The effect of IL on the thermal properties of both electrospun fibers and films is more noticeable when it was incorporated in PHBV, resulting in a general decrease of the melting temperature. For both polymer matrixes, an increase in the surface roughness of the films is observed as well as a decrease of the thermal stability and surface wettability upon IL incorporation, regardless of IL content. Upon inclusion of the IL, the samples presented ionic conductivity values of 3.46 × 108 S cm1 for PHBV + IL 15% electrospun fibers, 1.53 × 1010 S cm1 for PVDF + IL 15% fibers, and 3.27 × 1010 S cm1 for PVDF + IL 15% films. Finally, the potential of the materials for tissue engineering is demonstrated by cytocompatibility assays.This work was supported by the Spanish State Research Agency (AEI) and the European Regional Development Fund (ERFD) through the project PID2019-106099RB-C43/AEI/10.13039/501100011033. Financial support from the Basque Government Industry departments under the ELKARTEK program is also acknowledged. The authors acknowledge funding by the Fundaçao ˜ para a Ciˆencia e Tecnologia (FCT) and by ERDF through COMPETE2020 - Programa Operacional Competitividade e Internacionalizaçao ˜ (POCI) in the framework of the Strategic Programs UID/FIS/04650/2020 and project PTDC/BTM-MAT/ 28237/2017. Also, the authors thank FCT for the research grants 2021.08158.BD (JPS), SFRH/BD/148655/2019 (RMM) and SFRH/ BPD/121526/2016 (DMC), and CR thanks the FCT for the contract under the Stimulus of Scientific Employment (2020.04163.CEECIND).info:eu-repo/semantics/publishedVersio

Poly(lactic-co-glycolide) based biodegradable electrically and magnetically active microenvironments for tissue regeneration applications

Polymer scaffolds are playing an increasing role in tissue engineering (TE), although there is still a need to improve their biomimicry of cellular microenvironments, by having smart scaffolds with an active response, which can improve tissue regeneration. This work reports on the novel combination of poly(lactic-co-glycolide) (PLGA) with the ionic liquid (IL) choline bis(trifluoromethylsulfonyl)imide ([Chol][TFSI]) or with iron oxide nanoparticles (Fe3O4, NP) in order to achieve biodegradable scaffolds with electroactive and magnetoactive response, respectively. The composites were processed into fiber and film morphologies. PLGA + IL fibers present diameters between 1.92 and 3.26 µm, decreased mechanical stiffness and elongation at yield with respect to the pristine polymer, and some fiber concentrations are not biocompatible. PLGA + IL films present a mean roughness 6.58 nm, increased mechanical stiffness with respect to the pristine polymer and decreased elongation at yield. The inclusion of IL increased the electrical conductivity of the polymer by 4 orders or magnitude.The diameter of PLGA + Fe3O4 fibers ranged from 0.62 to 1.36 µm, show an effective magnetic NP content yield between 52 and 78%, decreased stiffness and increased elongation at yield. PLGA + Fe3O4 films show a mean roughness of 5.07 nm, effective NP content yield between 77 and 97%, increased stiffness and elongation at yield. Cytotoxicity assays indicate that the PLGA + Fe3O4 materials are suitable for biomedical applications, independently of the filler content and morphology, whereas the IL containing samples are non-cytotoxic only in film morphology up to 5% wt. IL content. Finally, it is demonstrated that dynamic magneto mechanical stimulation of the PLGA + Fe3O4 samples allows the acceleration of the degradation rate of the samples.This work was supported by the Spanish State Research Agency (AEI) and the European Regional Development Fund (ERFD) through the project PID2019-106099RB-C43/AEI/10.13039/501100011033. Financial support from the Basque Government Industry departments under the ELKARTEK program is also acknowledged. The authors acknowledge funding by the Fundação para a Ciência e Tecnologia (FCT) and by ERDF through COMPETE2020 - Programa Operacional Competitividade e Internacionalização (POCI) in the framework of the Strategic Programs UID/FIS/04650/2020 and project PTDC/BTM MAT/28237/2017. Also, the authors thank FCT for the research grant SFRH/BPD/121526/2016 (DMC), SFRH/BD/148655/2019 (RMM) and 2021.08158.BD (JPS), and CR thanks the FCT for the contract under the Stimulus of Scientific Employment (2020.04163.CEECIND)

Environmentally friendly carrageenan-based ionic-liquid driven soft actuators

Naturally derived polymer based on iota carrageenan and different ammonium and imidazolium based ionic liquids (ILs) are used for the development of environmentally friendly soft actuators. The influence of IL content and type and solvent evaporation temperature on the morphological and physico-chemical properties of the materials was evaluated, together with the effect on actuator functional response. Independently of the IL content, type, and solvent evaporation temperature a non-porous structure is obtained. The incorporation of the IL within the polymer matrix does not affect the thermal stability but leads to a decrease in the Young Modulus for the different IL/carrageenan samples. The highest influence was observed by using the [Ch][DHP] IL at a filler content of 40 w/w % with a decrease in the Young Modulus from 748 MPa for the neat polymer to 145 MPa for the [Ch][DHP]/carrageenan sample. Further, the ionic conductivity of the samples increases with increasing IL content, with the highest values being 2.9×10-6 S/cm and 1.2 ×10-6 S/cm for the samples with 40 w/w % of [Bmim][FeCl4] and [Ch][DHP], respectively. Regarding the soft actuator performance, the maximum displacement was obtained for the [Ch][DHP]/carrageenan sample with an IL content of 40 w/w %, showing a maximum displacement of 5.8 mm at a DC applied voltage of 9 V.Work supported by the Portuguese Foundation for Science and Technology (FCT) under strategic funding UID/FIS/04650/2020, UID/QUI/0686/2020, UIDB/50006/2020 and UIDP/50006/2020, project PTDC/FIS-MAC/28157/2017, and grants SFRH/BD/145345/2019 (LCF), SFRH/BPD/121526/2016 (D.M.C), and Investigator FCT Contract 2020.04028.CEECIND (C.M.C.). The authors thank funding by the Spanish State Research Agency (AEI) and the European Regional Development Fund (ERFD) through the project PID2019-106099RB-C43 / AEI / 10.13039/501100011033. The authors also acknowledge funding from the Basque Government Industry and Education Departments under the ELKARTEK, HAZITEK and PIBA (PIBA-2018-06) programs, respectively. Technical and human support provided by SGIker (UPV/EHU, MICINN, GV/EJ, EGEF and ESF) is gratefully acknowledge