There is provided a polyolefin resin foam sheet formed by foaming a polyolefin resin, wherein the expansion ratio of the foam sheet is 1.5 to 20 cm.sup.3/g, the average cell sizes in the MD direction and the TD direction of the foam sheet are 130 μm or less, and the following formulas (1) and (2) are satisfied:
T.sub.M/D≥6  (1); and
T.sub.T/D≥5  (2), where T.sub.M denotes the tensile strength at 90° C. in the MD direction, T.sub.T denotes the tensile strength at 90° C. in the TD direction, and D denotes the density (g/cm.sup.3) of the foam sheet.

A foam containing a nitrile group-containing conjugated diene copolymer and a urethane polymer, wherein relative to 100 wt % of the sum of the nitrile group-containing conjugated diene copolymer and the urethane polymer, the nitrile group-containing conjugated diene copolymer is present in an amount of less than 90 wt % and the urethane polymer is present in an amount of more than 10 wt %, the nitrile group-containing conjugated diene copolymer contains ethylenically unsaturated nitrile monomer units in an amount of more than 31 wt %, the foam has a density of 0.08 to 0.30 g/cm.sup.3, and in observation of an arbitrary cross section of the foam, air bubble cross sections present in the cross section have an average diameter of 350 μm or less, and the number of air bubble cross sections with a diameter of 0.6 mm or more present in the cross section is 0.062 per mm.sup.2 or less.

Example methods include depositing a precursor layer onto a substrate where the precursor layer includes droplets comprising a polymerizable material, inducing a phase inversion in the precursor layer to obtain a modified precursor layer including droplets of a non-polymerizable liquid within a polymerizable liquid mixture, and polymerizing the polymerizable liquid mixture to obtain a nanovoided polymer element. Examples include devices fabricated using nanovoided polymer elements fabricated using such methods, including electroactive devices such as actuators and sensors.

An optical element includes a nanovoided polymer layer having a first refractive index in an unactuated state and a second refractive index different than the first refractive index in an actuated state. Compression or expansion of the nanovoided polymer layer, for instance, can be used to reversibly control the size and shape of the nanovoids within the polymer layer and hence tune its refractive index over a range of values, e.g., during operation of the optical element. Various other apparatuses, systems, materials, and methods are also disclosed.

The present invention relates to a complex and a material containing the same for oil-water separation. The preparation process of the complex is simple. The complex shows lipophilicity, superhydrophobicity, and super water-repellency since a zinc oxide particle layer, in which zinc oxide particles are agglomerated in a micro-nano structure, and a super-hydrophobic coating layer having low surface energy are sequentially formed on a surface of a polymer matrix having a cavernous porous structure, and thus the complex has high oil-water separation efficiency and high durability. When a magnetic particle layer exhibiting magnetism is provided between the zinc oxide particle layer and the super-hydrophobic coating layer, the positional control and collection of the complex is easy, and thus the complex can be helpfully used as a material for oil absorption type oil-water separation, which is used in large-scale oil-water separation, such as the removal of oil spilled into the ocean.

The present invention includes a hydrogel and a method of making a porous hydrogel by preparing an aqueous mixture of an uncrosslinked polymer and a crystallizable molecule; casting the mixture into a vessel; allowing the cast mixture to dry to form an amorphous hydrogel film; seeding the cast mixture with a seed crystal of the crystallizable molecule; growing the crystallizable molecule into a crystal structure within the uncrosslinked polymer; crosslinking the polymer around the crystal structure under conditions in which the crystal structure within the crosslinked polymer is maintained; and dissolving the crystals within the crosslinked polymer to form the porous hydrogel.

A display device includes a scanned projector for projecting a beam of light, and a diffraction grating for dispersing the light at a plurality of angles into a waveguide, wherein at least a portion of the diffraction grating includes a nanovoided polymer. Manipulation of the nanovoid topology, such as through capacitive actuation, can be used to reversibly control the effective refractive index of the nanovoided polymer and hence the grating efficiency. The switchable grating can be used to control the amount of diffraction of an incident beam of light through the grating thereby decreasing optical loss. Various other methods, systems, apparatuses, and materials are also disclosed.

In some examples, a device includes a nanovoided polymer element, a planarization layer disposed on a surface of the nanovoided polymer element, a first electrode disposed on the planarization layer, and a second electrode. The nanovoided polymer element may be located at least in part between the first electrode and the second electrode. The planarization layer may be located between the nanovoided polymer element and the first electrode.

When a polymer gel has excellent mechanical strength and an ability to maintain surface wetness for a longer time, the polymer gel may be very widely applied to a variety of fields. The present disclosure provides example embodiments of a polymer gel having excellent mechanical strength and an ability to maintain surface wetness for a longer time. Further, the present disclosure provides example embodiments of a method of preparing the polymer gel.

Expanded particles of a polycarbonate-based resin containing a polycarbonate-based resin containing a component derived from bisphenol A as abase resin, the expanded particles being expanded particles of a polycarbonate-based resin satisfying any one of the following conditions (a) to (c) in a GC/MS chart: (a) a peak derived from a molecular weight of from 145 to 230 and a peak derived from a molecular weight of from 320 to 350 are shown; (b) a peak derived from a molecular weight of from 210 to 230 is shown; and (c) a peak derived from a molecular weight of from 290 to 320 is shown.