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Martin Jansen - One of the best experts on this subject based on the ideXlab platform.
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exploring the route to 1 3 5 triazine 2 4 6 Triisocyanate c6n6o3 a hydrogen free molecular precursor for polymeric c n o materials
European Journal of Inorganic Chemistry, 2012Co-Authors: Carsten Schmidt, Martin JansenAbstract:We report on the synthesis of 1,3,5-triazine-2,4,6-Triisocyanate [C3N3(NCO)3]. The hydrogen-free compound, a new molecular precursor for the realisation of C–N–(O) networks (e.g., C2N2O, C3N4), has been obtained in a five-step reaction sequence with well-defined intermediates. Starting from cyanoformiate, triethyl 1,3,5-triazine-2,4,6-tricarboxylate (C12O6N3H15) was prepared and identified by means of spectroscopic and thermal methods. In addition, the crystal structures of two modifications were solved [high temperature (HT): P63/m (no. 176), a = 11.07(2) A, c = 6.83(4) A, γ = 120°, V = 725.80(2) A3, Z = 2; low temperature (LT): P21/n (no. 14), a = 21.75(2) A, b = 6.54(5) A, c = 21.81(0) A, β = 119.81(0)°, V = 2693.98(6) A3, Z = 8]. Hydrolysis of the ester under alkaline conditions (KOH) yielded the corresponding salt of 1,3,5-triazine-2,4,6-tricarboxylic acid, C3N3(COO)3K3·2H2O [P (no. 2), a = 6.95(0) A, b = 17.45(8) A, c = 17.54(1) A, α = 119.76(0)°, β = 92.04(0)°, γ = 93.92(0) °A; V = 1837.63(0) A3, Z = 6]. The dried salt was converted into 1,3,5-triazine-2,4,6-tricarbonyl trichloride [C3N3(COCl)3] by reaction with POCl3. The trichloride was also studied by means of single-crystal structure analysis [P21/c (no. 14), a = 9.73(6) A, b = 11.21(1) A, c = 17.03(1) A, β = 91.91(1)°, V = 1857.87(23) A3, Z = 8]. Further reaction of the molecular acid chloride with AgN3 gave the acyl azide, which was converted in situ into the product 1,3,5-triazine-2,4,6-Triisocyanate by means of a thermally induced Curtius rearrangement. The final product was studied by thermal and spectroscopic methods. Owing to the high chemical reactivity of the isocyanate groups, oligomerisation/polymerisation of the molecular compound occurred immediately at room temperature, thus forming amorphous uretdione-type coordination compounds. The uretdione-based network has been converted into the corresponding molecular carbamates (R–NH–CO–OR) by reaction with ethanol [P63/m (no. 176), a = 14.873(12) A, c = 6.605(7) A, γ = 120°, Z = 2, V = 1265(2) A3] and 2-propanol [P43 (no. 78), a = 13.526(8) A, c = 12.956(2) A, Z = 4, V = 2370.5(3) A3]. The potential of this new precursor in the field of carbon nitrides as well as carbon oxynitrides is discussed briefly.
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Exploring the Route to 1,3,5‐Triazine‐2,4,6‐Triisocyanate (C6N6O3), a Hydrogen‐Free Molecular Precursor for Polymeric C–N–(O) Materials
European Journal of Inorganic Chemistry, 2012Co-Authors: Carsten Schmidt, Martin JansenAbstract:We report on the synthesis of 1,3,5-triazine-2,4,6-Triisocyanate [C3N3(NCO)3]. The hydrogen-free compound, a new molecular precursor for the realisation of C–N–(O) networks (e.g., C2N2O, C3N4), has been obtained in a five-step reaction sequence with well-defined intermediates. Starting from cyanoformiate, triethyl 1,3,5-triazine-2,4,6-tricarboxylate (C12O6N3H15) was prepared and identified by means of spectroscopic and thermal methods. In addition, the crystal structures of two modifications were solved [high temperature (HT): P63/m (no. 176), a = 11.07(2) A, c = 6.83(4) A, γ = 120°, V = 725.80(2) A3, Z = 2; low temperature (LT): P21/n (no. 14), a = 21.75(2) A, b = 6.54(5) A, c = 21.81(0) A, β = 119.81(0)°, V = 2693.98(6) A3, Z = 8]. Hydrolysis of the ester under alkaline conditions (KOH) yielded the corresponding salt of 1,3,5-triazine-2,4,6-tricarboxylic acid, C3N3(COO)3K3·2H2O [P (no. 2), a = 6.95(0) A, b = 17.45(8) A, c = 17.54(1) A, α = 119.76(0)°, β = 92.04(0)°, γ = 93.92(0) °A; V = 1837.63(0) A3, Z = 6]. The dried salt was converted into 1,3,5-triazine-2,4,6-tricarbonyl trichloride [C3N3(COCl)3] by reaction with POCl3. The trichloride was also studied by means of single-crystal structure analysis [P21/c (no. 14), a = 9.73(6) A, b = 11.21(1) A, c = 17.03(1) A, β = 91.91(1)°, V = 1857.87(23) A3, Z = 8]. Further reaction of the molecular acid chloride with AgN3 gave the acyl azide, which was converted in situ into the product 1,3,5-triazine-2,4,6-Triisocyanate by means of a thermally induced Curtius rearrangement. The final product was studied by thermal and spectroscopic methods. Owing to the high chemical reactivity of the isocyanate groups, oligomerisation/polymerisation of the molecular compound occurred immediately at room temperature, thus forming amorphous uretdione-type coordination compounds. The uretdione-based network has been converted into the corresponding molecular carbamates (R–NH–CO–OR) by reaction with ethanol [P63/m (no. 176), a = 14.873(12) A, c = 6.605(7) A, γ = 120°, Z = 2, V = 1265(2) A3] and 2-propanol [P43 (no. 78), a = 13.526(8) A, c = 12.956(2) A, Z = 4, V = 2370.5(3) A3]. The potential of this new precursor in the field of carbon nitrides as well as carbon oxynitrides is discussed briefly.
Carsten Schmidt - One of the best experts on this subject based on the ideXlab platform.
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exploring the route to 1 3 5 triazine 2 4 6 Triisocyanate c6n6o3 a hydrogen free molecular precursor for polymeric c n o materials
European Journal of Inorganic Chemistry, 2012Co-Authors: Carsten Schmidt, Martin JansenAbstract:We report on the synthesis of 1,3,5-triazine-2,4,6-Triisocyanate [C3N3(NCO)3]. The hydrogen-free compound, a new molecular precursor for the realisation of C–N–(O) networks (e.g., C2N2O, C3N4), has been obtained in a five-step reaction sequence with well-defined intermediates. Starting from cyanoformiate, triethyl 1,3,5-triazine-2,4,6-tricarboxylate (C12O6N3H15) was prepared and identified by means of spectroscopic and thermal methods. In addition, the crystal structures of two modifications were solved [high temperature (HT): P63/m (no. 176), a = 11.07(2) A, c = 6.83(4) A, γ = 120°, V = 725.80(2) A3, Z = 2; low temperature (LT): P21/n (no. 14), a = 21.75(2) A, b = 6.54(5) A, c = 21.81(0) A, β = 119.81(0)°, V = 2693.98(6) A3, Z = 8]. Hydrolysis of the ester under alkaline conditions (KOH) yielded the corresponding salt of 1,3,5-triazine-2,4,6-tricarboxylic acid, C3N3(COO)3K3·2H2O [P (no. 2), a = 6.95(0) A, b = 17.45(8) A, c = 17.54(1) A, α = 119.76(0)°, β = 92.04(0)°, γ = 93.92(0) °A; V = 1837.63(0) A3, Z = 6]. The dried salt was converted into 1,3,5-triazine-2,4,6-tricarbonyl trichloride [C3N3(COCl)3] by reaction with POCl3. The trichloride was also studied by means of single-crystal structure analysis [P21/c (no. 14), a = 9.73(6) A, b = 11.21(1) A, c = 17.03(1) A, β = 91.91(1)°, V = 1857.87(23) A3, Z = 8]. Further reaction of the molecular acid chloride with AgN3 gave the acyl azide, which was converted in situ into the product 1,3,5-triazine-2,4,6-Triisocyanate by means of a thermally induced Curtius rearrangement. The final product was studied by thermal and spectroscopic methods. Owing to the high chemical reactivity of the isocyanate groups, oligomerisation/polymerisation of the molecular compound occurred immediately at room temperature, thus forming amorphous uretdione-type coordination compounds. The uretdione-based network has been converted into the corresponding molecular carbamates (R–NH–CO–OR) by reaction with ethanol [P63/m (no. 176), a = 14.873(12) A, c = 6.605(7) A, γ = 120°, Z = 2, V = 1265(2) A3] and 2-propanol [P43 (no. 78), a = 13.526(8) A, c = 12.956(2) A, Z = 4, V = 2370.5(3) A3]. The potential of this new precursor in the field of carbon nitrides as well as carbon oxynitrides is discussed briefly.
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Exploring the Route to 1,3,5‐Triazine‐2,4,6‐Triisocyanate (C6N6O3), a Hydrogen‐Free Molecular Precursor for Polymeric C–N–(O) Materials
European Journal of Inorganic Chemistry, 2012Co-Authors: Carsten Schmidt, Martin JansenAbstract:We report on the synthesis of 1,3,5-triazine-2,4,6-Triisocyanate [C3N3(NCO)3]. The hydrogen-free compound, a new molecular precursor for the realisation of C–N–(O) networks (e.g., C2N2O, C3N4), has been obtained in a five-step reaction sequence with well-defined intermediates. Starting from cyanoformiate, triethyl 1,3,5-triazine-2,4,6-tricarboxylate (C12O6N3H15) was prepared and identified by means of spectroscopic and thermal methods. In addition, the crystal structures of two modifications were solved [high temperature (HT): P63/m (no. 176), a = 11.07(2) A, c = 6.83(4) A, γ = 120°, V = 725.80(2) A3, Z = 2; low temperature (LT): P21/n (no. 14), a = 21.75(2) A, b = 6.54(5) A, c = 21.81(0) A, β = 119.81(0)°, V = 2693.98(6) A3, Z = 8]. Hydrolysis of the ester under alkaline conditions (KOH) yielded the corresponding salt of 1,3,5-triazine-2,4,6-tricarboxylic acid, C3N3(COO)3K3·2H2O [P (no. 2), a = 6.95(0) A, b = 17.45(8) A, c = 17.54(1) A, α = 119.76(0)°, β = 92.04(0)°, γ = 93.92(0) °A; V = 1837.63(0) A3, Z = 6]. The dried salt was converted into 1,3,5-triazine-2,4,6-tricarbonyl trichloride [C3N3(COCl)3] by reaction with POCl3. The trichloride was also studied by means of single-crystal structure analysis [P21/c (no. 14), a = 9.73(6) A, b = 11.21(1) A, c = 17.03(1) A, β = 91.91(1)°, V = 1857.87(23) A3, Z = 8]. Further reaction of the molecular acid chloride with AgN3 gave the acyl azide, which was converted in situ into the product 1,3,5-triazine-2,4,6-Triisocyanate by means of a thermally induced Curtius rearrangement. The final product was studied by thermal and spectroscopic methods. Owing to the high chemical reactivity of the isocyanate groups, oligomerisation/polymerisation of the molecular compound occurred immediately at room temperature, thus forming amorphous uretdione-type coordination compounds. The uretdione-based network has been converted into the corresponding molecular carbamates (R–NH–CO–OR) by reaction with ethanol [P63/m (no. 176), a = 14.873(12) A, c = 6.605(7) A, γ = 120°, Z = 2, V = 1265(2) A3] and 2-propanol [P43 (no. 78), a = 13.526(8) A, c = 12.956(2) A, Z = 4, V = 2370.5(3) A3]. The potential of this new precursor in the field of carbon nitrides as well as carbon oxynitrides is discussed briefly.
Zhi-yuan Wang - One of the best experts on this subject based on the ideXlab platform.
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Ultrafast nonresonant third-order optical nonlinearity of fullerene-containing polyurethane films at telecommunication wavelengths
Applied Physics Letters, 2003Co-Authors: Qiying Chen, Li Kuang, Edward H Sargent, Zhi-yuan WangAbstract:High-optical-quality polyurethane films containing a high load of (60)fullerene (C60) were prepared by reaction of the hydroxy-containing C60 and Triisocyanate with the goal of obtaining enhanced nonresonant third-order optical nonlinearity. Optical nonlinearity was measured using the Z-scan technique in the wavelength range 1150–1600 nm. This revealed a positive Kerr coefficient with nonresonant n2 equal to 2.0(±0.6)×10−3 cm2/GW and excellent linear-absorption and nonlinear-absorption figures of merit at 1550 nm. The technique reported herein is a new approach to obtain fullerene films with the capacity to realize a high number density of C60 moieties. These resulted in more than 2 orders of enhancement in the third-order susceptibility over recently reported C60 sol and gel, and an enlarged second-order hyperpolarizability resulting from further enhanced charge transfer processes.High-optical-quality polyurethane films containing a high load of (60)fullerene (C60) were prepared by reaction of the hydroxy-containing C60 and Triisocyanate with the goal of obtaining enhanced nonresonant third-order optical nonlinearity. Optical nonlinearity was measured using the Z-scan technique in the wavelength range 1150–1600 nm. This revealed a positive Kerr coefficient with nonresonant n2 equal to 2.0(±0.6)×10−3 cm2/GW and excellent linear-absorption and nonlinear-absorption figures of merit at 1550 nm. The technique reported herein is a new approach to obtain fullerene films with the capacity to realize a high number density of C60 moieties. These resulted in more than 2 orders of enhancement in the third-order susceptibility over recently reported C60 sol and gel, and an enlarged second-order hyperpolarizability resulting from further enhanced charge transfer processes.
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Ultrafast nonresonant third-order optical nonlinearity of fullerene-containing polyurethane films at telecommunication wavelengths
Applied Physics Letters, 2003Co-Authors: Qiying Chen, Li Kuang, Edward H Sargent, Zhi-yuan WangAbstract:High-optical-quality polyurethane films containing a high load of (60)fullerene (C-60) were prepared by reaction of the hydroxy-containing C-60 and Triisocyanate with the goal of obtaining enhanced nonresonant third-order optical nonlinearity. Optical nonlinearity was measured using the Z-scan technique in the wavelength range 1150-1600 nm. This revealed a positive Kerr coefficient with nonresonant n(2) equal to 2.0(+/-0.6)x10(-3) cm(2)/GW and excellent linear-absorption and nonlinear-absorption figures of merit at 1550 nm. The technique reported herein is a new approach to obtain fullerene films with the capacity to realize a high number density of C-60 moieties. These resulted in more than 2 orders of enhancement in the third-order susceptibility over recently reported C-60 sol and gel, and an enlarged second-order hyperpolarizability resulting from further enhanced charge transfer processes. (C) 2003 American Institute of Physics.
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[60]Fullerene-Containing Polyurethane Films with Large Ultrafast Nonresonant Third-Order Nonlinearity at Telecommunication Wavelengths
Journal of the American Chemical Society, 2003Co-Authors: Li Kuang, Qiying Chen, Edward H Sargent, Zhi-yuan WangAbstract:A significantly enhanced, ultrafast third-order optical nonlinearity at the wavelengths of 1150-1600 nm was demonstrated with cross-linked C60-containing polyurethane films using the Z-scan technique. Good-quality polymer films with a high loading of C60 derivative were obtained by cross-linking of the hydroxyl-containing C60 derivative and a Triisocyanate. The positive Kerr coefficient with nonresonant nonlinear refractive index n2 falls in the range of (3.7 +/- 0.80) x 10-4 to (2.0 +/- 0.6) x 10-3 cm2/GW, and the calculated chi(3) and gamma values are up to 9.7 x 10-11 and 9.6 x 10-32 esu at 1550 nm, which are several orders of enhancement in third-order optical nonlinearity over pristine C60 in solution and 1-2 orders of enhancement over recently reported C60 derivatives and conjugated polymers.
Nicholas Leventis - One of the best experts on this subject based on the ideXlab platform.
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Nanostructure-Dependent Marcus-Type Correlation of the Shape Recovery Rate and the Young’s Modulus in Shape Memory Polymer Aerogels
ACS Applied Materials & Interfaces, 2018Co-Authors: Suraj Donthula, Mary Ann B Meador, Chandana Mandal, James Schisler, Theodora Leventis, Lia Sotiriou-leventis, Nicholas LeventisAbstract:Thermodynamic–kinetic relationships are not uncommon, but rigorous correlations are rare. On the basis of the parabolic free-energy profiles of elastic deformation, a generalized Marcus-type thermodynamic–kinetic relationship was identified between the shape recovery rate, Rt(N), and the elastic modulus, E, in poly(isocyanurate-urethane) shape memory aerogels. The latter were prepared with mixtures of diethylene, triethylene, and tetraethylene glycol and an aliphatic Triisocyanate. Synthetic conditions were selected using a statistical design of experiments method. Microstructures obtained in each formulation could be put into two groups, one consisting of micron-size particles connected with large necks and a second one classified as bicontinuous. The two types of microstructures could be explained consistently by spinodal decomposition involving early versus late phase separation relative to the gel point. Irrespective of microstructure, all samples showed a shape memory effect with shape fixity and sha...
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Sturdy, Monolithic SiC and Si3N4 Aerogels from Compressed Polymer-Cross-Linked Silica Xerogel Powders
Chemistry of Materials, 2018Co-Authors: Parwani M Rewatkar, Adnan Malik Saeed, Suraj Donthula, Tahereh Taghvaee, Chandana Mandal, Chariklia Sotiriou-leventis, Theodora Leventis, Naveen Chandrasekaran, T. K. Shruthi, Nicholas LeventisAbstract:We report the carbothermal synthesis of sturdy, highly porous (>85%) SiC and Si3N4 monolithic aerogels from compressed polyurea-cross-linked silica xerogel powders. The high porosity in those articles was created via reaction of core silica nanoparticles with their carbonized polymer coating toward the new ceramic framework and CO that escaped. Sol–gel silica powder was obtained by disrupting gelation of a silica sol with vigorous agitation. The grains of the powder were about 50 μm in size and irregular in shape and consisted of 3D assemblies of silica nanoparticles as in any typical silica gel. The individual elementary silica nanoparticles within the grains of the powder were coated conformally with a nanothin layer of carbonizable polyurea derived from the reaction of an aromatic Triisocyanate (TIPM: triisocyanatophenyl methane) with the innate −OH, deliberately added −NH2 groups, and adsorbed water on the surface of silica nanoparticles. The wet-gel powder was dried at ambient temperature under vacuu...
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Selective CO2 Sequestration with Monolithic Bimodal Micro/Macroporous Carbon Aerogels Derived from Stepwise Pyrolytic Decomposition of Polyamide-Polyimide-Polyurea Random Copolymers
ACS Applied Materials & Interfaces, 2017Co-Authors: Adnan Malik Saeed, Suraj Donthula, Parwani M Rewatkar, Tahereh Taghvaee, Chandana Mandal, Chariklia Sotiriou-leventis, Nicholas LeventisAbstract:Polymeric aerogels (PA-xx) were synthesized via room-temperature reaction of an aromatic Triisocyanate (tris(4-isocyanatophenyl) methane) with pyromellitic acid. Using solid-state CPMAS 13C and 15N NMR, it was found that the skeletal framework of PA-xx was a statistical copolymer of polyamide, polyurea, polyimide, and of the primary condensation product of the two reactants, a carbamic–anhydride adduct. Stepwise pyrolytic decomposition of those components yielded carbon aerogels with both open and closed microporosity. The open micropore surface area increased from
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nanoporous polyurea from a Triisocyanate and boric acid a paradigm of a general reaction pathway for isocyanates and mineral acids
Chemistry of Materials, 2016Co-Authors: Nicholas Leventis, Chariklia Sotiriouleventis, Adnan Malik Saeed, Suraj Donthula, Parwani M Rewatkar, H Kaiser, David J Robertson, Hongbing Lu, Gitogo ChuruAbstract:Isocyanates react with carboxylic acids and yield amides. As reported herewith, however, transferring that reaction to a range of mineral acids (anhydrous H3BO3, H3PO4, H3PO3, H2SeO3, H6TeO6, H5IO6, and H3AuO3) yields urea. The model system for this study was a Triisocyanate, tris(4-isocyanatophenyl)methane (TIPM), reacting with boric acid in DMF at room temperature, yielding nanoporous polyurea networks that were dried with supercritical fluid CO2 to robust aerogels (referred to as BPUA-xx). BPUA-xx were structurally (CHN, solid-state 13C NMR) and nanoscopically (SEM, SAXS, N2-sorption) identical to the reaction product of the same Triisocyanate (TIPM) and water (referred to as PUA-yy). Minute differences were detected in the primary particle radius (6.2–7.5 nm for BPUA-xx versus 7.0–9.0 nm for PUA-yy), the micropore size within primary particles (6.0–8.5 A for BPUA-xx versus 8.0–10 A for PUA-yy), and the solid-state 15N NMR whereas PUA-yy showed some dangling −NH2. All data together were consistent with...
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Flexible Aerogels From Hyperbranched Polyurethanes: Probing the Role of Molecular Rigidity with Poly(Urethane Acrylates) vs. . Poly(Urethane Norbornenes)
Chemistry of Materials, 2014Co-Authors: Abhishek Bang, Lia Sotiriou-leventis, Clayton Buback, Nicholas LeventisAbstract:Flexible and foldable aerogels have commercial value for applications in thermal insulation. This study investigates the molecular connection of macroscopic flexibility using polymeric aerogels based on star-shaped polyurethane-acrylate versus urethane-norbornene monomers. The core of those monomers is based either on a rigid/aromatic, or a flexible/aliphatic Triisocyanate. Terminal acrylates or norbornenes at the tips of the star branches were polymerized with free radical chemistry, or with ROMP, respectively. At the molecular level, aerogels were characterized with FTIR and solid-state 13C NMR. The porous network was probed with N2-sorption and Hg-intrusion porosimetry, SEM and SAXS. The interparticle connectivity was assessed in a top-down fashion with thermal conductivity measurements and compression testing. All aerogels of this study consist of aggregates of nanoparticles, whose size depends on the aliphatic/aromatic content of the monomer, the rigidity/flexibility of the polymeric backbone, and ge...
Qiying Chen - One of the best experts on this subject based on the ideXlab platform.
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Ultrafast nonresonant third-order optical nonlinearity of fullerene-containing polyurethane films at telecommunication wavelengths
Applied Physics Letters, 2003Co-Authors: Qiying Chen, Li Kuang, Edward H Sargent, Zhi-yuan WangAbstract:High-optical-quality polyurethane films containing a high load of (60)fullerene (C60) were prepared by reaction of the hydroxy-containing C60 and Triisocyanate with the goal of obtaining enhanced nonresonant third-order optical nonlinearity. Optical nonlinearity was measured using the Z-scan technique in the wavelength range 1150–1600 nm. This revealed a positive Kerr coefficient with nonresonant n2 equal to 2.0(±0.6)×10−3 cm2/GW and excellent linear-absorption and nonlinear-absorption figures of merit at 1550 nm. The technique reported herein is a new approach to obtain fullerene films with the capacity to realize a high number density of C60 moieties. These resulted in more than 2 orders of enhancement in the third-order susceptibility over recently reported C60 sol and gel, and an enlarged second-order hyperpolarizability resulting from further enhanced charge transfer processes.High-optical-quality polyurethane films containing a high load of (60)fullerene (C60) were prepared by reaction of the hydroxy-containing C60 and Triisocyanate with the goal of obtaining enhanced nonresonant third-order optical nonlinearity. Optical nonlinearity was measured using the Z-scan technique in the wavelength range 1150–1600 nm. This revealed a positive Kerr coefficient with nonresonant n2 equal to 2.0(±0.6)×10−3 cm2/GW and excellent linear-absorption and nonlinear-absorption figures of merit at 1550 nm. The technique reported herein is a new approach to obtain fullerene films with the capacity to realize a high number density of C60 moieties. These resulted in more than 2 orders of enhancement in the third-order susceptibility over recently reported C60 sol and gel, and an enlarged second-order hyperpolarizability resulting from further enhanced charge transfer processes.
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Ultrafast nonresonant third-order optical nonlinearity of fullerene-containing polyurethane films at telecommunication wavelengths
Applied Physics Letters, 2003Co-Authors: Qiying Chen, Li Kuang, Edward H Sargent, Zhi-yuan WangAbstract:High-optical-quality polyurethane films containing a high load of (60)fullerene (C-60) were prepared by reaction of the hydroxy-containing C-60 and Triisocyanate with the goal of obtaining enhanced nonresonant third-order optical nonlinearity. Optical nonlinearity was measured using the Z-scan technique in the wavelength range 1150-1600 nm. This revealed a positive Kerr coefficient with nonresonant n(2) equal to 2.0(+/-0.6)x10(-3) cm(2)/GW and excellent linear-absorption and nonlinear-absorption figures of merit at 1550 nm. The technique reported herein is a new approach to obtain fullerene films with the capacity to realize a high number density of C-60 moieties. These resulted in more than 2 orders of enhancement in the third-order susceptibility over recently reported C-60 sol and gel, and an enlarged second-order hyperpolarizability resulting from further enhanced charge transfer processes. (C) 2003 American Institute of Physics.
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[60]Fullerene-Containing Polyurethane Films with Large Ultrafast Nonresonant Third-Order Nonlinearity at Telecommunication Wavelengths
Journal of the American Chemical Society, 2003Co-Authors: Li Kuang, Qiying Chen, Edward H Sargent, Zhi-yuan WangAbstract:A significantly enhanced, ultrafast third-order optical nonlinearity at the wavelengths of 1150-1600 nm was demonstrated with cross-linked C60-containing polyurethane films using the Z-scan technique. Good-quality polymer films with a high loading of C60 derivative were obtained by cross-linking of the hydroxyl-containing C60 derivative and a Triisocyanate. The positive Kerr coefficient with nonresonant nonlinear refractive index n2 falls in the range of (3.7 +/- 0.80) x 10-4 to (2.0 +/- 0.6) x 10-3 cm2/GW, and the calculated chi(3) and gamma values are up to 9.7 x 10-11 and 9.6 x 10-32 esu at 1550 nm, which are several orders of enhancement in third-order optical nonlinearity over pristine C60 in solution and 1-2 orders of enhancement over recently reported C60 derivatives and conjugated polymers.
