California Institute of Technology

City of Hope

Raymond Weitekamp

Robert H Grubbs

Garret M Miyake

Victoria Piunova

Harry A Atwater

Christopher Scot Daeffler

Yan Xia

Benjamin R Sveinbjornsson

Thomas P Russell

Jacob Berlin

Sung Woo Hong

Slobodan Mitrovic

Krishnan Thyagarajan

Desiree Van Haute

James Fakonas

Oana R Luca

Weiyin Gu

The present invention relates to methods of metathesizing olefins using catalysts previously considered to be practically inactive. The present invention further relates to novel photosensitive compositions, their use as photoresists, and methods related to patterning polymer layers on substrates. Further, modifications to the compositions and method provide for an unprecedented functionalization of the compositions, useful for example in the preparation of sensors, drug delivery systems, and tissue scaffolds. The novel compositions and associated methods also provide for the opportunity to prepare 3-dimensional objects which provide new access to critically dimensioned devices, including for example photonic devices.

Direct photopatterning of robust and diverse materials

The invention provides a class of block copolymers having a plurality of chemically different blocks, at least a portion of which incorporating polymer side chain groups having a helical secondary structure. The invention also provides structures generated by self-assembly of polymer blends including at least one block copolymer component, such as a brush block polymer or wedge-type block polymer. The invention provides, for example, periodic nanostructures and microstructures generated by self-assembly of block copolymers and polymer blends comprising a mixture of at least one block copolymer component, such as a brush block copolymer, and at least a second component.

Photonic structures from self assembly of brush block copolymers and polymer blends

The devices can be fabricated by a method that permits active polymer chains to be polymerized on the surface of an electrode such that the active polymer chains are aligned with one another. The active polymer chains can also be covalently linked to a second electrode so the active polymer chains are located in an active layer of the device. The polymerization method can be paused and resumed at any point in the polymerization so nanoparticles can be added into the active layer. Additionally, the polymerization method allows that active polymer chains to be polymerized so they include junctions such as p-n junctions and Schottky junctions.

Electronic devices employing aligned organic polymers

The invention provides a class of wedge-type block copolymers having a plurality of chemically different blocks, at least a portion of which incorporates a wedge group-containing block providing useful properties. For example, use of one or more wedge group-containing blocks in some block copolymers of the invention significantly inhibits chain entanglement and, thus, the present block copolymers materials provide a class of polymer materials capable of efficient molecular self-assembly to generate a range of structures, such as periodic nanostructures and microstructures. Materials of the present invention include copolymers having one or more wedge group-containing blocks, and optionally for some applications copolymers also incorporating one or more polymer side group-containing blocks. The present invention also provides useful methods of making and using wedge-type block copolymers.

Periodic nanostructures from self assembled wedge-type block-copolymers

The present disclosure is directed to processes comprising irradiating an aggregate of chemically bonded or otherwise associated nanoparticles with a light source capable of providing multiphoton excitation, the light source directed at a focal point volume including the aggregate and having sufficient energy to disrupt or fuse the aggregate within the focal point volume to form nanoscale deposits of the nanoparticles.

Multiphoton induced direct aggregate scribing

A COreduction electrode includes an active layer on an electrode base. The active layer includes a polymer that includes one or more reaction components selected from a group consisting of a COreduction catalyst and an activator that bonds COso as to form a COreduction intermediate.

Confinement of reaction components at electrode surface

Described herein are copolymers constructed from chiral, non-racemic monomers, which self-assemble to photonic crystals. The difficulty of incorporating chiral elements into photonic crystals has limited the ability to generate unique bandstructures for different circular polarizations of light. The materials and methods described herein relate to easily, predictably fabricating chiral photonic crystals having desirable optical properties.

Chiral polymers for the self-assembly of photonic crystals

An efficient method for the preparation of backbone-substituted imidazolinium salts for use as N-heterocyclic carbene ligands, e.g., for organometallic catalysts is provided. These functionalized N-heterocyclic carbene ligands are used to prepare solid-supported catalysts, e.g., for olefin metathesis.

Functional N-heterocycles for solid-supported catalysis

The invention provides a class of copolymers having useful properties, including brush block copolymers, wedge-type block copolymers and hybrid wedge and polymer block copolymers. In an embodiment, for example, block copolymers of the invention incorporate chemically different blocks comprising polymer size chain groups and/or wedge groups that significantly inhibit chain entanglement, thereby enhancing molecular self-assembly processes for generating a range of supramolecular structures, such as periodic nanostructures and microstructures. The present invention also provides useful methods of making and using copolymers, including block copolymers.

Rapid self-assembly of block copolymers to photonic crystals

The disclosure describes a polymer brush structure exhibiting birefringence, said polymer brush structure comprising a plurality of substantially parallel oriented polymers and characterized by a longitudinal z-direction having a first refractive index, n, and a lateral x,y-direction having a second refractive index, n, wherein the difference, &#x394;n, between the first refractive index and the second refractive index is in a range of about 0.1 to about 0.6, as measured by ellipsometry and fit to a Cauchy analytical model.

Birefringent polymer brush structures formed by surface initiated ring-opening metathesis polymerization

The present invention provides photosensitive compositions and methods of patterning a polymeric image on a substrate, said methods comprising; (a) depositing a layer of photosensitive composition of any one of claimstoon the substrate; and (b) irradiating a portion of the layer of photosensitive composition with a light comprising a wavelength in a range of from about 220 to about 440 nm. The invention also relates to methods of metathesizing an unsaturated organic precursor comprising irradiating Fischer-type carbene ruthenium catalysts with at least one wavelength of light in the presence of at least one unsaturated organic precursor so as to metathesize at least one alkene or one alkyne bond.

Photoinitiated olefin methathesis polymerization

The disclosure describes methods of metathesizing unsaturated organic compounds, each method comprising contacting at least one feedstock comprising at least one olefinic or acetylenic precursor with a solid transition metal-based metathesis catalyst in the absence of a liquid solvent or precursor to form a polymer product.

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Glendale, CA, United States of America

Raymond Weitekamp