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Laurence Ramos

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University of Exeter

King's College London

University College Cork

María Cecilia Tomasini

Universidad de Buenos Aires

Prof. Dr. Hesham N Mustafa 🩺

King AbdulAziz University (KAU) Jeddah, Saudi Arabia

Università Cattolica del Sacro Cuore (Catholic University of the Sacred Heart)

North Carolina State University

Ege University

Edward Bormashenko

Ariel University

Ãsa Svenningsen

University of Southern Denmark

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Papers by Laurence Ramos

Impact of the protein composition on the structure and viscoelasticity of polymer-like gluten gels

Journal of Physics: Condensed Matter

Biaxial extensional viscous dissipation in sheets expansion formed by impact of drops of Newtonian and non-Newtonian fluids

Physical Review Fluids

We investigate freely expanding liquid sheets made of either simple Newtonian fluids or solutions... more We investigate freely expanding liquid sheets made of either simple Newtonian fluids or solutions of high molecular water-soluble polymer chains. A sheet is produced by the impact of a drop on a quartz plate covered with a thin layer of liquid nitrogen that suppresses shear viscous dissipation due to an inverse Leidenfrost effect. The sheet expands radially until reaching a maximum diameter and subsequently recedes. Experiments indicate the presence of two expansion regimes: the capillary regime, where the maximum expansion is controlled by surface tension forces and does not depend on the viscosity, and the viscous regime, where the expansion is reduced with increasing viscosity. In the viscous regime, the sheet expansion for polymeric samples is strongly enhanced as compared to that of Newtonian samples with comparable zero-shear viscosity. We show that data for Newtonian and non-Newtonian fluids collapse on a unique master curve where the maximum expansion factor is plotted against the relevant effective biaxial extensional Ohnesorge number that depends on fluid density, surface tension, and the biaxial extensional viscosity. For Newtonian fluids, this biaxial extensional viscosity is six times the shear viscosity. By contrast, for the non-Newtonian fluids, a characteristic Weissenberg number-dependent biaxial extensional viscosity is identified, which is in quantitative agreement with experimental and theoretical results reported in the literature for biaxial extensional flows of polymeric liquids.

Polypyrrole nanostructures modified with mono- and bimetallic nanoparticles for photocatalytic H2 generation

Journal of Materials Chemistry A

Conjugated polymer polypyrrole nanostructures modified with bimetallic (Pt–Ni) nanoparticles are ... more

Rearrangement Zone around a Crack Tip in a Double Self-Assembled Transient Network

ACS Macro Letters

Swollen hexagonal liquid crystals as smart nanoreactors: implementation in materials chemistry for energy applications

Nanoscale, Jan 29, 2018

Materials are the key roadblocks for the commercialization of energy conversion devices in fuel c... more Materials are the key roadblocks for the commercialization of energy conversion devices in fuel cells and solar cells. Significant research has focused on tuning the intrinsic properties of materials at the nanometer scale. The soft template mediated controlled fabrication of advanced nanostructured materials is attracting considerable interest due to the promising applications of these materials in catalysis and electrocatalysis. Swollen hexagonal lyotropic liquid crystals (SLCs) consist of oil-swollen surfactant-stabilized 1D, 2D or 3D nanometric assemblies regularly arranged in an aqueous solvent. Interestingly, the characteristic size of the SLCs can be controlled by adjusting the volume ratio of oil to water. The non-polar and/or polar compartments of the SLCs can be doped with guest molecules and used as nanoreactors for the synthesis of various metals (Pt, Pd, Au, etc.), conducting polymers and composite nanostructures with controlled size and shape. 1D, 2D and 3D mono- and b...

Compatibility between Solid Particles and a Lamellar Phase: A Crucial Role of the Membrane Interactions

The Journal of Physical Chemistry

... (2) Helfrich, W. Z. Naturforsch. 1978, 33A, 305. [CAS]. (3) Fabre, P.; Casagrande, C.; Veyssi... more

Reaction medium comprising a directly swollen liquid crystal

Elasticity of a swollen hexagonal phase

Rheology of Bridged Wormlike Micelles

物性研究, 2006

Visible-light active conducting polymer nanostructures with superior photocatalytic activity

Scientific Reports, 2015

The development of visible-light responsive photocatalysts would permit more efficient use of sol... more The development of visible-light responsive photocatalysts would permit more efficient use of solar energy, and thus would bring sustainable solutions to many environmental issues. Conductive polymers appear as a new class of very active photocatalysts under visible light. Among them poly(3,4ethylenedioxythiophene) (PEDOT) is one of the most promising conjugated polymer with a wide range of applications. PEDOT nanostructures synthesized in soft templates via chemical oxidative polymerization demonstrate unprecedented photocatalytic activities for water treatment without the assistance of sacrificial reagents or noble metal co-catalysts and turn out to be better than TiO 2 as benchmark catalyst. The PEDOT nanostructures exhibit a narrow band gap (E = 1.69 eV) and are characterized by excellent ability to absorb light in visible and near infrared region. The novel PEDOTbased photocatalysts are very stable with cycling and can be reused without appreciable loss of activity. Interestingly, hollow micrometric vesicular structures of PEDOT are not effective photocatalysts as compared to nanometric spindles suggesting size and shape dependent photocatalytic properties. The visible-light active photocatalytic properties of the polymer nanostructures present promising applications in solar light harvesting and broader fields.

Phases hexagonales dopees

Http Www Theses Fr, 1997

Real-Time Observation of Polyelectrolyte-lnduced Binding of Charged Bilayers

Journal of the American Chemical Society, 2007

Bursting of Dilute Emulsion-Based Liquid Sheets Driven by a Marangoni Effect

Physical Review Letters, 2015

We study the destabilization mechanism of thin liquid sheets expanding in air and show that dilut... more We study the destabilization mechanism of thin liquid sheets expanding in air and show that dilute oil-in-water emulsion-based sheets disintegrate through the nucleation and growth of holes that perforate the sheet. The velocity and thickness fields of the sheet outside the holes are not perturbed by holes and hole opening follows a Taylor-Culick law. We find that a pre-hole, which widens and thins out the sheet with time, systematically precedes the hole nucleation. The growth dynamics of the pre-hole follows the law theoretically predicted for a liquid spreading on another liquid of higher surface tension due to Marangoni stresses. Classical Marangoni spreading experiments quantitatively corroborate our findings.

Viscoelasticity of colloidal polycrystals doped with impurities

Physical Review E, 2015

We investigate how the microstructure of a colloidal polycrystal influences its linear visco-elas... more We investigate how the microstructure of a colloidal polycrystal influences its linear visco-elasticity. We use thermosensitive copolymer micelles that arrange in water in a cubic crystalline lattice, yielding a colloidal polycrystal. The polycrystal is doped with a small amount of nanoparticles, of size comparable to that of the micelles, which behave as impurities and thus partially segregate in the grain boundaries. We show that the shear elastic modulus only depends on the packing of the micelles and varies neither with the presence of nanoparticles nor with the crystal microstructure. By contrast, we find that the loss modulus is strongly affected by the presence of nanoparticles. A comparison between rheology data and small-angle neutron-scattering data suggests that the loss modulus is dictated by the total amount of nanoparticles in the grain boundaries, which in turn depends on the sample microstructure.

Free radially expanding liquid sheet in air: time- and space-resolved measurement of the thickness field

Journal of Fluid Mechanics, 2015

The collision of a liquid drop against a small target results in the formation of a thin liquid s... more The collision of a liquid drop against a small target results in the formation of a thin liquid sheet that extends radially until it reaches a maximum diameter. The subsequent retraction is due to the air–liquid surface tension. We have used a time- and space-resolved technique to measure the thickness field of this class of liquid sheet, based on the grey-level measurement of the image of a dyed liquid sheet recorded using a high-speed camera. This method enables a precise measurement of the thickness in the range $10{-}450~{\rm\mu}\text{m}$, with a temporal resolution equal to that of the camera. We have measured the evolution with time since impact, $t$, and radial position, $r$, of the thickness, $h(r,t)$, for various drop volumes and impact velocities. Two asymptotic regimes for the expansion of the sheet are evidenced. The scalings of the thickness with $t$ and $r$ measured in the two regimes are those that were predicted by Rozhkov et al. (Proc. R. Soc. Lond. A, vol. 460, 200...

Conducting Polymer Nanofibers of Controlled Diameter Synthesized in Hexagonal Mesophases

New J. Chem., 2015

Conducting poly(diphenylbutadiyne) (PDPB) nanofibers with controlled diameters (5 to 25 nm) and r... more

Spontaneous gelation of wheat gluten proteins in a food grade solvent

Food Hydrocolloids, 2015

Structuring wheat gluten proteins into gels with tunable mechanical properties would provide more... more Structuring wheat gluten proteins into gels with tunable mechanical properties would provide more versatility for the production of plant protein-rich food products. Gluten, a strongly elastic protein material insoluble in water, is hardly processable. We use a novel fractionation procedure allowing the isolation from gluten of a water/ethanol soluble protein blend, enriched in glutenin polymers at an unprecedented high ratio (50%). We investigate here the viscoelasticity of suspensions of the protein blend in a water/ethanol (50/50 v/v) solvent, and show that, over a wide range of concentrations, they undergo a spontaneous gelation driven by hydrogen bonding. We successfully rationalize our data using percolation models and relate the viscoelasticity of the gels to their fractal dimension measured by scattering techniques. The gluten gels display self-healing properties and their elastic plateaus cover several decades, from 0.01 to 10000 Pa. In particular very soft gels as compared to standard hydrated gluten can be produced.

Polymeric assembly of gluten proteins in an aqueous ethanol solvent

The journal of physical chemistry. B, Jan 25, 2014

The supramolecular organization of wheat gluten proteins is largely unknown due to the intrinsic ... more The supramolecular organization of wheat gluten proteins is largely unknown due to the intrinsic complexity of this family of proteins and their insolubility in water. We fractionate gluten in a water/ethanol mixture (50/50 v/v) and obtain a protein extract which is depleted in gliadin, the monomeric part of wheat gluten proteins, and enriched in glutenin, the polymeric part of wheat gluten proteins. We investigate the structure of the proteins in the solvent used for extraction over a wide range of concentration, by combining X-ray scattering and multiangle static and dynamic light scattering. Our data show that, in the ethanol/water mixture, the proteins display features characteristic of flexible polymer chains in a good solvent. In the dilute regime, the proteins form very loose structures of characteristic size 150 nm, with an internal dynamics which is quantitatively similar to that of branched polymer coils. In more concentrated regimes, data highlight a hierarchical structur...

Scaling with temperature and concentration of the nonlinear rheology of a soft hexagonal phase

Physical review. E, Statistical, nonlinear, and soft matter physics, 2001

The nonlinear rheology of a soft surfactant hexagonal phase is examined. The system exhibits a sh... more The nonlinear rheology of a soft surfactant hexagonal phase is examined. The system exhibits a shear-melting transition from a two-dimensional polycrystalline texture to a liquid of cylinders aligned along the flow [Ramos et al., Langmuir 16, 5846 (2000)]. This dynamic transition is associated with a discontinuity in the stress-strain curve (flow curve). A detailed study of the temperature and concentration dependence of the flow curves is presented. The nonlinear rheology is found to display a scaling behavior, when temperature or concentration are varied. We demonstrate that the whole behavior of the hexagonal phase under shear is essentially governed by the linear shear modulus of the sample, G0. When temperature is varied, we show that the two key parameters, which control G0 and in turn, the flow curve, are a transition temperature T(c) and an activation energy E(A). We propose E(A) to be related to the scission energy of one cylinder into two pieces.

Conducting polymer nanostructures for photocatalysis under visible light

Nature Materials, 2015

Visible-light-responsive photocatalysts can directly harvest energy from solar light, o ering a d... more Visible-light-responsive photocatalysts can directly harvest energy from solar light, o ering a desirable way to solve energy and environment issues 1. Here, we show that one-dimensional poly(diphenylbutadiyne) nanostructures synthesized by photopolymerization using a soft templating approach have high photocatalytic activity under visible light without the assistance of sacrificial reagents or precious metal co-catalysts. These polymer nanostructures are very stable even after repeated cycling. Transmission electron microscopy and nanoscale infrared characterizations reveal that the morphology and structure of the polymer nanostructures remain unchanged after many photocatalytic cycles. These stable and cheap polymer nanofibres are easy to process and can be reused without appreciable loss of activity. Our findings may help the development of semiconducting-based polymers for applications in self-cleaning surfaces, hydrogen generation and photovoltaics. Increasing attention is being drawn towards nanomaterials for photocatalytic solar-energy conversion to identify robust new methods for water purification and environmental protection at lower cost and energy consumption 1. For an optimized use of solar energy, efficient and stable photocatalysts that are capable of harvesting visible light are required. Over the past decades, oxide-based semiconductors, in particular TiO 2 , have been recognized as efficient photocatalysts for the degradation of organic pollutants in wastewater 2,3. The limitation of TiO 2 (like most other photocatalysts) 4 for applications is essentially due to the low quantum yield that results from charge-carrier (e − /h +) recombination and the necessity to use ultraviolet irradiation because of the large value of its bandgap 5. To overcome this limitation and produce photocatalysts responsive to visible light, surface-tuning strategies and modification of oxides on the nanometre scale have been developed through doping or surface modification 6. Indeed, TiO 2 doping with N, C or S, or its modification with metal nanoparticles (Ag, Au, Pt), has extended its activity towards the visible region 6,7. However, the photocatalytic activity of the modified materials in visible light is still not sufficient for commercial applications. Alternative materials have been proposed for photocatalysis and solar-energy conversion. For example, polymeric carbon nitride was found to be an efficient photocatalyst that produces hydrogen from water under visible light irradiation, but a sacrificial donor is required 8. Hence, large-scale production of stable visible-light-active photocatalysts remains a challenge for

Impact of the protein composition on the structure and viscoelasticity of polymer-like gluten gels

Journal of Physics: Condensed Matter

Biaxial extensional viscous dissipation in sheets expansion formed by impact of drops of Newtonian and non-Newtonian fluids

Physical Review Fluids

We investigate freely expanding liquid sheets made of either simple Newtonian fluids or solutions... more We investigate freely expanding liquid sheets made of either simple Newtonian fluids or solutions of high molecular water-soluble polymer chains. A sheet is produced by the impact of a drop on a quartz plate covered with a thin layer of liquid nitrogen that suppresses shear viscous dissipation due to an inverse Leidenfrost effect. The sheet expands radially until reaching a maximum diameter and subsequently recedes. Experiments indicate the presence of two expansion regimes: the capillary regime, where the maximum expansion is controlled by surface tension forces and does not depend on the viscosity, and the viscous regime, where the expansion is reduced with increasing viscosity. In the viscous regime, the sheet expansion for polymeric samples is strongly enhanced as compared to that of Newtonian samples with comparable zero-shear viscosity. We show that data for Newtonian and non-Newtonian fluids collapse on a unique master curve where the maximum expansion factor is plotted against the relevant effective biaxial extensional Ohnesorge number that depends on fluid density, surface tension, and the biaxial extensional viscosity. For Newtonian fluids, this biaxial extensional viscosity is six times the shear viscosity. By contrast, for the non-Newtonian fluids, a characteristic Weissenberg number-dependent biaxial extensional viscosity is identified, which is in quantitative agreement with experimental and theoretical results reported in the literature for biaxial extensional flows of polymeric liquids.

Polypyrrole nanostructures modified with mono- and bimetallic nanoparticles for photocatalytic H2 generation

Journal of Materials Chemistry A

Conjugated polymer polypyrrole nanostructures modified with bimetallic (Pt–Ni) nanoparticles are ... more

Rearrangement Zone around a Crack Tip in a Double Self-Assembled Transient Network

ACS Macro Letters

Swollen hexagonal liquid crystals as smart nanoreactors: implementation in materials chemistry for energy applications

Nanoscale, Jan 29, 2018

Materials are the key roadblocks for the commercialization of energy conversion devices in fuel c... more Materials are the key roadblocks for the commercialization of energy conversion devices in fuel cells and solar cells. Significant research has focused on tuning the intrinsic properties of materials at the nanometer scale. The soft template mediated controlled fabrication of advanced nanostructured materials is attracting considerable interest due to the promising applications of these materials in catalysis and electrocatalysis. Swollen hexagonal lyotropic liquid crystals (SLCs) consist of oil-swollen surfactant-stabilized 1D, 2D or 3D nanometric assemblies regularly arranged in an aqueous solvent. Interestingly, the characteristic size of the SLCs can be controlled by adjusting the volume ratio of oil to water. The non-polar and/or polar compartments of the SLCs can be doped with guest molecules and used as nanoreactors for the synthesis of various metals (Pt, Pd, Au, etc.), conducting polymers and composite nanostructures with controlled size and shape. 1D, 2D and 3D mono- and b...

Compatibility between Solid Particles and a Lamellar Phase: A Crucial Role of the Membrane Interactions

The Journal of Physical Chemistry

... (2) Helfrich, W. Z. Naturforsch. 1978, 33A, 305. [CAS]. (3) Fabre, P.; Casagrande, C.; Veyssi... more

Reaction medium comprising a directly swollen liquid crystal

Elasticity of a swollen hexagonal phase

Rheology of Bridged Wormlike Micelles

物性研究, 2006

Visible-light active conducting polymer nanostructures with superior photocatalytic activity

Scientific Reports, 2015

The development of visible-light responsive photocatalysts would permit more efficient use of sol... more The development of visible-light responsive photocatalysts would permit more efficient use of solar energy, and thus would bring sustainable solutions to many environmental issues. Conductive polymers appear as a new class of very active photocatalysts under visible light. Among them poly(3,4ethylenedioxythiophene) (PEDOT) is one of the most promising conjugated polymer with a wide range of applications. PEDOT nanostructures synthesized in soft templates via chemical oxidative polymerization demonstrate unprecedented photocatalytic activities for water treatment without the assistance of sacrificial reagents or noble metal co-catalysts and turn out to be better than TiO 2 as benchmark catalyst. The PEDOT nanostructures exhibit a narrow band gap (E = 1.69 eV) and are characterized by excellent ability to absorb light in visible and near infrared region. The novel PEDOTbased photocatalysts are very stable with cycling and can be reused without appreciable loss of activity. Interestingly, hollow micrometric vesicular structures of PEDOT are not effective photocatalysts as compared to nanometric spindles suggesting size and shape dependent photocatalytic properties. The visible-light active photocatalytic properties of the polymer nanostructures present promising applications in solar light harvesting and broader fields.

Phases hexagonales dopees

Http Www Theses Fr, 1997

Real-Time Observation of Polyelectrolyte-lnduced Binding of Charged Bilayers

Journal of the American Chemical Society, 2007

Bursting of Dilute Emulsion-Based Liquid Sheets Driven by a Marangoni Effect

Physical Review Letters, 2015

We study the destabilization mechanism of thin liquid sheets expanding in air and show that dilut... more We study the destabilization mechanism of thin liquid sheets expanding in air and show that dilute oil-in-water emulsion-based sheets disintegrate through the nucleation and growth of holes that perforate the sheet. The velocity and thickness fields of the sheet outside the holes are not perturbed by holes and hole opening follows a Taylor-Culick law. We find that a pre-hole, which widens and thins out the sheet with time, systematically precedes the hole nucleation. The growth dynamics of the pre-hole follows the law theoretically predicted for a liquid spreading on another liquid of higher surface tension due to Marangoni stresses. Classical Marangoni spreading experiments quantitatively corroborate our findings.

Viscoelasticity of colloidal polycrystals doped with impurities

Physical Review E, 2015

We investigate how the microstructure of a colloidal polycrystal influences its linear visco-elas... more We investigate how the microstructure of a colloidal polycrystal influences its linear visco-elasticity. We use thermosensitive copolymer micelles that arrange in water in a cubic crystalline lattice, yielding a colloidal polycrystal. The polycrystal is doped with a small amount of nanoparticles, of size comparable to that of the micelles, which behave as impurities and thus partially segregate in the grain boundaries. We show that the shear elastic modulus only depends on the packing of the micelles and varies neither with the presence of nanoparticles nor with the crystal microstructure. By contrast, we find that the loss modulus is strongly affected by the presence of nanoparticles. A comparison between rheology data and small-angle neutron-scattering data suggests that the loss modulus is dictated by the total amount of nanoparticles in the grain boundaries, which in turn depends on the sample microstructure.

Free radially expanding liquid sheet in air: time- and space-resolved measurement of the thickness field

Journal of Fluid Mechanics, 2015

The collision of a liquid drop against a small target results in the formation of a thin liquid s... more The collision of a liquid drop against a small target results in the formation of a thin liquid sheet that extends radially until it reaches a maximum diameter. The subsequent retraction is due to the air–liquid surface tension. We have used a time- and space-resolved technique to measure the thickness field of this class of liquid sheet, based on the grey-level measurement of the image of a dyed liquid sheet recorded using a high-speed camera. This method enables a precise measurement of the thickness in the range $10{-}450~{\rm\mu}\text{m}$, with a temporal resolution equal to that of the camera. We have measured the evolution with time since impact, $t$, and radial position, $r$, of the thickness, $h(r,t)$, for various drop volumes and impact velocities. Two asymptotic regimes for the expansion of the sheet are evidenced. The scalings of the thickness with $t$ and $r$ measured in the two regimes are those that were predicted by Rozhkov et al. (Proc. R. Soc. Lond. A, vol. 460, 200...

Conducting Polymer Nanofibers of Controlled Diameter Synthesized in Hexagonal Mesophases

New J. Chem., 2015

Conducting poly(diphenylbutadiyne) (PDPB) nanofibers with controlled diameters (5 to 25 nm) and r... more

Spontaneous gelation of wheat gluten proteins in a food grade solvent

Food Hydrocolloids, 2015

Structuring wheat gluten proteins into gels with tunable mechanical properties would provide more... more Structuring wheat gluten proteins into gels with tunable mechanical properties would provide more versatility for the production of plant protein-rich food products. Gluten, a strongly elastic protein material insoluble in water, is hardly processable. We use a novel fractionation procedure allowing the isolation from gluten of a water/ethanol soluble protein blend, enriched in glutenin polymers at an unprecedented high ratio (50%). We investigate here the viscoelasticity of suspensions of the protein blend in a water/ethanol (50/50 v/v) solvent, and show that, over a wide range of concentrations, they undergo a spontaneous gelation driven by hydrogen bonding. We successfully rationalize our data using percolation models and relate the viscoelasticity of the gels to their fractal dimension measured by scattering techniques. The gluten gels display self-healing properties and their elastic plateaus cover several decades, from 0.01 to 10000 Pa. In particular very soft gels as compared to standard hydrated gluten can be produced.

Polymeric assembly of gluten proteins in an aqueous ethanol solvent

The journal of physical chemistry. B, Jan 25, 2014

The supramolecular organization of wheat gluten proteins is largely unknown due to the intrinsic ... more The supramolecular organization of wheat gluten proteins is largely unknown due to the intrinsic complexity of this family of proteins and their insolubility in water. We fractionate gluten in a water/ethanol mixture (50/50 v/v) and obtain a protein extract which is depleted in gliadin, the monomeric part of wheat gluten proteins, and enriched in glutenin, the polymeric part of wheat gluten proteins. We investigate the structure of the proteins in the solvent used for extraction over a wide range of concentration, by combining X-ray scattering and multiangle static and dynamic light scattering. Our data show that, in the ethanol/water mixture, the proteins display features characteristic of flexible polymer chains in a good solvent. In the dilute regime, the proteins form very loose structures of characteristic size 150 nm, with an internal dynamics which is quantitatively similar to that of branched polymer coils. In more concentrated regimes, data highlight a hierarchical structur...

Scaling with temperature and concentration of the nonlinear rheology of a soft hexagonal phase

Physical review. E, Statistical, nonlinear, and soft matter physics, 2001

The nonlinear rheology of a soft surfactant hexagonal phase is examined. The system exhibits a sh... more The nonlinear rheology of a soft surfactant hexagonal phase is examined. The system exhibits a shear-melting transition from a two-dimensional polycrystalline texture to a liquid of cylinders aligned along the flow [Ramos et al., Langmuir 16, 5846 (2000)]. This dynamic transition is associated with a discontinuity in the stress-strain curve (flow curve). A detailed study of the temperature and concentration dependence of the flow curves is presented. The nonlinear rheology is found to display a scaling behavior, when temperature or concentration are varied. We demonstrate that the whole behavior of the hexagonal phase under shear is essentially governed by the linear shear modulus of the sample, G0. When temperature is varied, we show that the two key parameters, which control G0 and in turn, the flow curve, are a transition temperature T(c) and an activation energy E(A). We propose E(A) to be related to the scission energy of one cylinder into two pieces.

Conducting polymer nanostructures for photocatalysis under visible light

Nature Materials, 2015

Visible-light-responsive photocatalysts can directly harvest energy from solar light, o ering a d... more Visible-light-responsive photocatalysts can directly harvest energy from solar light, o ering a desirable way to solve energy and environment issues 1. Here, we show that one-dimensional poly(diphenylbutadiyne) nanostructures synthesized by photopolymerization using a soft templating approach have high photocatalytic activity under visible light without the assistance of sacrificial reagents or precious metal co-catalysts. These polymer nanostructures are very stable even after repeated cycling. Transmission electron microscopy and nanoscale infrared characterizations reveal that the morphology and structure of the polymer nanostructures remain unchanged after many photocatalytic cycles. These stable and cheap polymer nanofibres are easy to process and can be reused without appreciable loss of activity. Our findings may help the development of semiconducting-based polymers for applications in self-cleaning surfaces, hydrogen generation and photovoltaics. Increasing attention is being drawn towards nanomaterials for photocatalytic solar-energy conversion to identify robust new methods for water purification and environmental protection at lower cost and energy consumption 1. For an optimized use of solar energy, efficient and stable photocatalysts that are capable of harvesting visible light are required. Over the past decades, oxide-based semiconductors, in particular TiO 2 , have been recognized as efficient photocatalysts for the degradation of organic pollutants in wastewater 2,3. The limitation of TiO 2 (like most other photocatalysts) 4 for applications is essentially due to the low quantum yield that results from charge-carrier (e − /h +) recombination and the necessity to use ultraviolet irradiation because of the large value of its bandgap 5. To overcome this limitation and produce photocatalysts responsive to visible light, surface-tuning strategies and modification of oxides on the nanometre scale have been developed through doping or surface modification 6. Indeed, TiO 2 doping with N, C or S, or its modification with metal nanoparticles (Ag, Au, Pt), has extended its activity towards the visible region 6,7. However, the photocatalytic activity of the modified materials in visible light is still not sufficient for commercial applications. Alternative materials have been proposed for photocatalysis and solar-energy conversion. For example, polymeric carbon nitride was found to be an efficient photocatalyst that produces hydrogen from water under visible light irradiation, but a sacrificial donor is required 8. Hence, large-scale production of stable visible-light-active photocatalysts remains a challenge for