摘要:
Composite polymer films or layers have graphene-based nanosheets dispersed in the polymer for the reduction of gas permeability and light transmittance.
摘要:
A macroscale sheet laminate includes individual graphene oxide sheets layered one on another in a manner to form a self-supporting paper-like laminated product. The product can be fabricated by making a suspension of individual graphene oxide sheets and assembling the graphene oxide sheets as a laminate on a fluid-permeable support by flow-directed assembly. The laminate is dried and released from the membrane filter as a self-supporting sheet laminate.
摘要:
Ruthenium and osmium carbene compounds that are stable in the presence of a variety of functional groups and can be used to catalyze olefin metathesis reactions on unstrained cyclic and acyclic olefins are disclosed. Also disclosed are methods of making the carbene compounds. The carbene compounds are of the formula where M is Os or Ru; R1 is hydrogen; R is selected from the group consisting of hydrogen, substituted or unsubstituted alkyl, and substituted or unsubstituted aryl; X and X1 are independently selected from any anionic ligand; and L and L1 are independently selected from any neutral electron donor. The ruthenium and osmium carbene compounds of the present invention may be synthesized using diazo compounds, by neutral electron donor ligand exchange, by cross metathesis, using acetylene, using cumulated olefins, and in a one-pot method using diazo compounds and neutral electron donors. The ruthenium and osmium carbene compounds of the present invention may be used to catalyze olefin metathesis reactions including, but not limited to, ROMP, RCM, depolymerization of unsaturated polymers, synthesis of telechelic polymers, and olefin synthesis.
摘要:
A method of making a dispersion of reduced graphite oxide nanoplatelets involves providing a dispersion of graphite oxide nanoplatelets and reducing the graphite oxide nanoplatelets in the dispersion in the presence of a reducing agent and a polymer. The reduced graphite oxide nanoplatelets are reduced to an extent to provide a higher C/O ratio than graphite oxide. A stable dispersion having polymer-treated reduced graphite oxide nanoplatelets dispersed in a dispersing medium, such as water or organic liquid is provided. The polymer-treated, reduced graphite oxide nanoplatelets can be distributed in a polymer matrix to provide a composite material.
摘要:
A ceramic composite thin film or layer includes individual graphene oxide and/or electrically conductive graphene sheets dispersed in a ceramic (e.g. silica) matrix. The thin film or layer can be electrically conductive film or layer depending the amount of graphene sheets present. The composite films or layers are transparent, chemically inert and compatible with both glass and hydrophilic SiOx/silicon substrates. The composite film or layer can be produced by making a suspension of graphene oxide sheet fragments, introducing a silica-precursor or silica to the suspension to form a sol, depositing the sol on a substrate as thin film or layer, at least partially reducing the graphene oxide sheets to conductive graphene sheets, and thermally consolidating the thin film or layer to form a silica matrix in which the graphene oxide and/or graphene sheets are dispersed.
摘要翻译:陶瓷复合薄膜或层包括分散在陶瓷(例如二氧化硅)基体中的单独的石墨烯氧化物和/或导电石墨烯薄片。 根据存在的石墨烯片的量,薄膜或层可以是导电膜或层。 复合膜或层是透明的,化学惰性的并且与玻璃和亲水性SiO x /硅衬底兼容。 可以通过制备氧化石墨烯片片段的悬浮液,将二氧化硅前体或二氧化硅引入悬浮液以形成溶胶,将溶胶沉积在基材上作为薄膜或层,来制备复合膜或层,至少部分地减少 氧化石墨烯片与导电石墨烯片,并且热固化该薄膜或层以形成其中分散有氧化石墨烯和/或石墨烯片的二氧化硅基质。
摘要:
Ruthenium and osmium carbene compounds that are stable in the presence of a variety of functional groups and can be used to catalyze olefin metathesis reactions on unstrained cyclic and acyclic olefins are disclosed. Also disclosed are methods of making the carbene compounds. The carbene compounds are of the formula where M is Os or Ru; R is hydrogen; R is selected from the group consisting of hydrogen, substituted or unsubstituted alkyl, and substituted or unsubstituted aryl; X and X are independently selected from any anionic ligand; and L and L are independently selected from any neutral electron donor. The ruthenium and osmium carbene compounds of the present invention may be synthesized using diazo compounds, by neutral electron donor ligand exchange, by cross metathesis, using acetylene, using cumulated olefins, and in a one-pot method using diazo compounds and neutral electron donors. The ruthenium and osmium carbene compounds of the present invention may be used to catalyze olefin metathesis reactions including, but not limited to, ROMP, RCM, depolymerization of unsaturated polymers, synthesis of telechelic polymers, and olefin synthesis.
摘要:
Ruthenium and osmium carbene compounds that are stable in the presence of a variety of functional groups and can be used to catalyze olefin metathesis reactions on unstrained cyclic and acyclic olefins are disclosed. Also disclosed are methods of making the carbene compounds. The carbene compounds are of the formula where M is Os or Ru; R1 is hydrogen; R is selected from the group consisting of hydrogen, substituted or unsubstituted alkyl, and substituted or unsubstituted aryl; X and X1 are independently selected from any anionic ligand; and L and L1 are independently selected from any neutral electron donor. The ruthenium and osmium carbene compounds of the present invention may be synthesized using diazo compounds, by neutral electron donor ligand exchange, by cross metathesis, using acetylene, using cumulated olefins, and in a one-pot method using diazo compounds and neutral electron donors. The ruthenium and osmium carbene compounds of the present invention may be used to catalyze olefin metathesis reactions including, but not limited to, ROMP, RCM, depolymerization of unsaturated polymers, synthesis of telechelic polymers, and olefin synthesis.
摘要:
Ruthenium and osmium carbene compounds that are stable in the presence of a variety of functional groups and can be used to catalyze olefin metathesis reactions on unstrained cyclic and acyclic olefins are disclosed. Also disclosed are methods of making the carbene compounds. The carbene compounds are of the formula ##STR1## where M is Os or Ru; R.sup.1 is hydrogen; R is selected from the group consisting of hydrogen, substituted or unsubstituted alkyl, and substituted or unsubstituted aryl; X and X.sup.1 are independently selected from any anionic ligand; and L and L.sup.1 are independently selected from any neutral electron donor. The ruthenium and osmium carbene compounds of the present invention may be synthesized using diazo compounds, by neutral electron donor ligand exchange, by cross metathesis, using acetylene, using cumulated olefins, and in a one-pot method using diazo compounds and neutral electron donors. The ruthenium and osmium carbene compounds of the present invention may be used to catalyze olefin metathesis reactions including, but not limited to, ROMP, RCM, depolymerization of unsaturated polymers, synthesis of telechelic polymers, and olefin synthesis.
摘要:
Disclosed are ruthenium and osmium carbene compounds which are stable in the presence of a variety of functional groups and which can be used to catalyze olefin metathesis reactions on strained and unstrained cyclic and acyclic olefins. Specifically, the present invention relates to carbene compounds of the formula ##STR1## wherein: M is Os or Ru; R and R.sup.1 are independently selected from hydrogen and substituent groups C.sub.2 -C.sub.20 alkenyl, C.sub.2 -C.sub.20 alkynyl, C.sub.1 -C.sub.20 alkyl, aryl, C.sub.1 -C.sub.20 carboxylate, C.sub.2 -C.sub.20 alkoxy, C.sub.2 -C.sub.20 alkenyloxy, C.sub.2 -C.sub.20 alkynyloxy, aryloxy, C.sub.2 -C.sub.20 alkoxycarbonyl, C.sub.1 -C.sub.20 alkylthio, C.sub.1 -C.sub.20 alkylsulfonyl or C.sub.1 -C.sub.20 alkylsulfinyl; each substituent group optionally substituted with C.sub.1 -C.sub.5 alkyl, a halogen, C.sub.1 -C.sub.5 alkoxy or with a phenyl group optionally substituted with a halogen, C.sub.1 -C.sub.5 alkyl or C.sub.1 -C.sub.5 alkoxy; X and X.sup.1 are independently selected from any anionic ligand; and L and L.sup.1 are each trialkyl phosphine ligands where at least one of the alkyl groups on the phosphine is a secondary alkyl or a cycloalkyl. A broad array of metathesis reactions are enabled including ring-opening metathesis polymerization of cyclic olefins, ring closing metathesis of acyclic dienes, cross metathesis involving at least one acyclic or unstrained cyclic olefin, depolymerization of unsaturated polymers and synthesis of telechelic polymers.
摘要:
A macroscale, self-supporting, composite laminate sheet includes individual, layered graphene oxide sheets and a polymer in spaces between the sheets. This composite product can be fabricated by combining a suspension of individual graphene oxide sheets and a solution of polymer, passing the resulting fluid through a fluid-permeable support, and assembling the graphene oxide sheets and polymer as a laminate sheet by flow-directed assembly. The laminate is dried and released from the membrane filter as a self-supporting thin films.