Highly Enhanced Vapor Sensing of Multiwalled Carbon Nanotube Network Sensors by n-Butylamine Functionalization

The sensing of volatile organic compounds by multiwall carbon nanotube networks of randomly entangled pristine nanotubes or the nanotubes functionalized by n-butylamine, which were deposited on polyurethane supporting electrospinned nonwoven membrane, has been investigated. The results show that the sensing of volatile organic compounds by functionalized nanotubes considerably increases with respect to pristine nanotubes. The increase is highly dependent on used vapor polarity. For the case of highly polar methanol, the functionalized MWCNT network exhibits even more than eightfold higher sensitivity in comparison to the network prepared from pristine nanotubes

Super-Adhesive Polymer–Silica Nanocomposite Layers

Atomized spray plasma deposition (ASPD) using a precursor mixture of 2-hydroxyethyl methacrylate and methacryloyl-functionalized 15 nm silica nanoparticles leads to the formation of poly(2-hydroxyethyl methacrylate)–silica nanocomposite layers. The direct application of these coatings to overlapping glass–glass joints gives rise to excellent in situ adhesion reaching 84 MPa shear bond strength and 6 GPa shear modulus prior to the onset of adherent (bulk glass) failure. This significant enhancement in interfacial adhesion arises due to the silica nanoparticle surface methacryloyl groups enhancing cross-linking throughout the nanocomposite layer

Melt grafting of sepiolite nanoclay onto poly(3-hydroxybutyrate-co-4-hydroxybutyrate) by reactive extrusion with multi-functional epoxy-based styrene-acrylic oligomer

[EN] This paper deals with grafting of sepiolite nanoclay onto poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P(3HB-co-4HB)) biopolymer by melt compounding. Reactive extrusion was performed in a twin-screw extruder in the presence of an epoxy-based styrene-acrylic oligomer (ESAO). The chemical interaction of sepiolite with P(3HB-co-4HB) were investigated using Fourier transform infrared (FTIR) spectroscopy. A novel grafting mechanism was proposed based on the multiple epoxy groups present in the reactive coupling agent. Epoxy ring-opening generated, on the one hand, the formation of alkoxy silanes bonds with the silanol groups exposed on the external surface of pristine sepiolite. On the other hand, ester bonds were produced with the terminal acid groups of the biopolymer chains. The newly formed sepiolite-grafted P(3HB-co-4HB) (sepiolite-g-P(3HB-co-4HB)) nanocomposite showed higher thermal, thermomechanical, and mechanical performance than the equivalent ungrafted nanocomposite. Melt grafting of sepiolite at different weight contents (1, 3, and 5 wt.-%) interestingly increased the thermal stability and stiffness of P(3HB-co-4HB) without impairing its ductility and toughness.The Spanish Ministry of Economy and Competitiveness is acknowledged for funding support through the research project MAT2014-59242-C2-1-R and the Torres Quevedo program of Dr. Torres-Giner (PTQ-11-04733). Quiles-Carrillo also thanks "Generalitat Valenciana" for his FPI grant (ACIF/2016/182). The authors thank Pr. Chris Sammon from Sheffield Hallam University for his support during FTIR characterization.Torres Giner, S.; Montañés Muñoz, N.; Boronat Vitoria, T.; Quiles Carrillo, LJ.; Balart Gimeno, RA. (2016). Melt grafting of sepiolite nanoclay onto poly(3-hydroxybutyrate-co-4-hydroxybutyrate) by reactive extrusion with multi-functional epoxy-based styrene-acrylic oligomer. European Polymer Journal. 84:693-707. https://doi.org/10.1016/j.eurpolymj.2016.09.057S6937078