Front Cover: Electrically actuating and waveguiding amorphous polymer submicron fibers can be used to produce novel opto–electromechanical devices. The fibers are further functionalized by embedding other functional materials. This cover image represents dye-embedded light-emitting amorphous submicron fibers which actuate in response to the polarity of an applied voltage and guide the emitted light in the fibers. This is reported by Yuya Ishii, Taiki Nobeshima, Heisuke Sakai, Keisho Omori, Sei Uemura and Mitsuo Fukuda in article number 1700302.

Inside Front Cover: A highly sensitive stretchable strain sensor, which consists of elastic fibrous membrane coated with conducting polymer is introduced. The sensor can detect applied strain by measuring the conductance change caused by the change in the nanocracking structure on the coated conducting polymer. This is reported by Hyungkook Jeon, Seong Kyung Hong, Seong J. Cho and Geunbae Lim in article number 1700389.

This review discusses the extent to the scale of the electrospun fiber membrane. A projection is taken to be accomplished whether the nanofiber production can be consistently raised to commercial levels at the exceptional application routes so far produced by the conventional electrospinning means.

A highly sensitive stretchable strain sensor is introduced, which consists of elastic fibrous membrane coated with conducting polymer. The sensor can detect applied strain by measuring the conductance change caused by the change in the nanocracking structure on the coated conducting polymer. Furthermore, by aligning microfibers, the sensitivity of the sensor is dramatically enhanced (more than 40-fold higher).

By carefully understanding the phase separation and crystallization behavior of poly(ε-caprolactone) (PCL)-based blends, one can tune the spatial distribution of the PCL phase, the growth of PCL crystalline regions, and therefore the amount and the sensitivity of amorphous PCL chains in response to solvent vapor annealing treatment. This will allow the easy and reliable production of hierarchically structured polymer materials with high regularity.

The properties of novel electrically actuating and waveguiding amorphous polymer submicron fibers are investigated in detail. These fibers guide light at subwavelength diameters with a group velocity greater than 0.71c₀. The fiber mat also demonstrates electrical actuation with a high apparent piezoelectric constant of ≈29 000 × 10⁻¹² m V⁻¹. Extremely small and functional waveguides can be used to produce novel opto-electromechanical devices.

Tailoring of bioinspired bicomponent fiber structures in a simple way and unambiguous characterization of complex fiber structures by combination of Raman imaging with atomic force microscopy, giving access to promising applications as actuators or for water harvesting, is highlighted.

The manufacture of all-cellulose composites (ACCs) reinforced with high-strength rayon fibers is reported. Solutions of cellulose in the ionic liquid 1-ethyl-3-methyl imidazolium acetate are used as matrix precursors. Full recycling of these ACCs is successfully demonstrated in several cycles by using the recycled material for subsequent matrix preparation without any significant loss in mechanic performance.

This paper describes a means of creating an enzyme-degradable hydrogel with mechanical properties approximating those of soft connective tissues such as the articular cartilage and meniscus. These properties are achieved through Michael-type addition crosslinking of a bis-cysteine peptide with a terminally acrylated 4-arm-poly(ethylene glycol) (4a-PEG)-block-oligo(trimethylene carbonate).

Norbornene-anhydride-functionalized linear polyethylenes from catalytic insertion copolymerization under mild conditions provide a high impact resistance to nylon-6,6 that compares favorably to existing impact modifiers, at ambient and low temperatures. Morphologies of the blends underline a strong binding between the microphases.

A house-of-cards structure is proposed for two different 2D nanomaterials (graphene oxide and montmorillonite) interacting electrostatically. Such behavior is manifested by a dramatic change in viscosity leading to the formation of a hydrogel, which is later used as a precursor for the fabrication of aerogels. The materials are promising for oil–spill cleanup and oil–water separation.

Methacrylated vanillyl alcohol (MVA) monomer shows promising results as a bio-based comonomer to replace styrene for maleinated acrylated epoxidized soybean-oil (MAESO) resins and exhibits advantages in terms of low volatility, sustainability, environmental friendliness, good processability, and improved glass transition temperature. Moreover, both methacrylated vanillyl alcohol and MAESO resin are derived from bio-based renewable resource.

Blending polystyrene-b-poly(ethylene-r-butylene)-b-polystyrene (SEBS) elastomer with functionalized graphene (FG) dispersions in tetrahydrofuran prior to melt processing enables uniform dispersion of single- and few-layer FG, whereas nonfunctionalized graphite yields larger graphene stacks together with micrometer-sized graphite. SEBS/FG composites exhibit superior mechanical properties with higher Shore A hardness, electrical conductivity at a lower percolation threshold, and enhanced gas barrier resistance.

Primary nanoparticle architecture, size, and initial concentration have a high impact on the mechanical stability and morphology of polymeric materials produced from colloidal dispersion via reactive gelation. Appropriately tuning those parameters allows the reliable control on the pore size distribution and the production of highly porous materials.

The development of nanocarrier-based technology is hampered by the difficulty to scale-up the production of reproducible and size-controlled nanoparticles. Here a versatile and scalable approach is reported for the large-scale synthesis of polymer nanocarriers from water-in-oil miniemulsions.