Marek Grzelczak - Academia.edu (original) (raw)
Uploads
Papers by Marek Grzelczak
IEEE Transactions on Consumer Electronics, 2012
We report the direct formation of multiwalled carbon nanotubes (MWNT) by ultrasonication of graph... more We report the direct formation of multiwalled carbon nanotubes (MWNT) by ultrasonication of graphite in dimethylformamide (DMF) upon addition of ferrocene aldehyde (Fc-CHO). The tubular structures appear exclusively at the edges of graphene layers and contain Fe clusters. Fc in conjunction with benzyl aldehyde, or other Fc derivatives, does not induce formation of NT. Higher amounts of Fc-CHO added to the dispersion do not increase significantly MWNT formation. Increasing the temperature reduces the amount of formation of MWNTs and shows the key role of ultrasound-induced cavitation energy. It is concluded that Fc-CHO first reduces the concentration of radical reactive species that slice graphene into small moieties, localizes itself at the edges of graphene, templates the rolling up of a sheet to form a nanoscroll, where it remains trapped, and finally accepts and donates unpaired electron to the graphene edges and converts the less stable scroll into a MWNT. This new methodology matches the long held notion that CNTs are rolled up graphene layers. The proposed mechanism is general and will lead to control the production of carbon nanostructures by simple ultrasonication treatments.
Journal of Materials Chemistry, 2006
... Influence of silver ions on the growth mode of platinum on gold nanorods. Marek Grzelczak, Jo... more ... Influence of silver ions on the growth mode of platinum on gold nanorods. Marek Grzelczak, Jorge Pérez-Juste, Benito Rodríguez-González and Luis M. Liz-Marzán J. Mater. Chem., 2006, 16, 3946-3951. DOI: 10.1039/B606887A ...
methylpyrrolidone were successfully functionalized using the 1,3-dipolar cycloaddition of azometh... more methylpyrrolidone were successfully functionalized using the 1,3-dipolar cycloaddition of azomethine ylides. The amino functional groups attached to graphene sheets were quantified by the Kaiser test. These amino groups selectively bind to gold nanorods, which were introduced as contrast markers for the identification of the graphene reactive sites. The interaction between gold nanorods and functionalized graphene was followed by UV؊vis spectroscopy. The presence of the organic groups was confirmed by X-ray photoelectron spectroscopy and thermogravimetric analysis. The sheets were characterized by transmission electron microscopy, demonstrating the presence of gold nanorods distributed uniformly all over the graphene surface. This observation indicates that reaction has taken place not just at the edges but also at the internal CAC bonds of graphene. Our results identify exfoliated graphene as a considerably more reactive structure than graphite and hence open the possibility to control the functionalization for use as a scaffold in the construction of organized composite nanomaterials.
Anisotropic, magnetic nickel shells were grown on gold nanorods [1] and on carbon nanotubes (CNT)... more Anisotropic, magnetic nickel shells were grown on gold nanorods [1] and on carbon nanotubes (CNT) [2] using Pt nanocrystals as catalysts. We used high resolution transmission electron microscopy (HRTEM) to characterize these well-defined metallic nickel shells.
Langmuir, 2009
We report the formation of porous gold nanoparticles with unusual, angled shapes (such as nanoche... more We report the formation of porous gold nanoparticles with unusual, angled shapes (such as nanocheckmarks) through spontaneous transformation of tellurium sacrificial templates by gradual galvanic replacement. High-resolution electron microscopy studies of intermediate stages reveal interesting information regarding the replacement mechanism, which involves initial "gold island growth" at the edges, and gradual branching to engulf the entire particle templates, resulting in a highly porous structure. Additionally, the high porosity of these novel nanostructures with unusual shapes is demonstrated to provide very high enhancement of the Raman scattering signal from adsorbed molecules.
In this tutorial review, we summarise recent research into the controlled growth of gold nanopart... more In this tutorial review, we summarise recent research into the controlled growth of gold nanoparticles of different morphologies and discuss the various chemical mechanisms that have been proposed to explain anisotropic growth. With the overview and discussion, we intended to select those published procedures that we consider more reliable and promising for synthesis of morphologies of interest. We expect this
Cheminform, 2008
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
methylpyrrolidone were successfully functionalized using the 1,3-dipolar cycloaddition of azometh... more methylpyrrolidone were successfully functionalized using the 1,3-dipolar cycloaddition of azomethine ylides. The amino functional groups attached to graphene sheets were quantified by the Kaiser test. These amino groups selectively bind to gold nanorods, which were introduced as contrast markers for the identification of the graphene reactive sites. The interaction between gold nanorods and functionalized graphene was followed by UV؊vis spectroscopy. The presence of the organic groups was confirmed by X-ray photoelectron spectroscopy and thermogravimetric analysis. The sheets were characterized by transmission electron microscopy, demonstrating the presence of gold nanorods distributed uniformly all over the graphene surface. This observation indicates that reaction has taken place not just at the edges but also at the internal CAC bonds of graphene. Our results identify exfoliated graphene as a considerably more reactive structure than graphite and hence open the possibility to control the functionalization for use as a scaffold in the construction of organized composite nanomaterials.
Journal of Physical Chemistry B, 2005
The alignment of multiwalled carbon nanotubes (MWNTs) has been accomplished through deposition of... more The alignment of multiwalled carbon nanotubes (MWNTs) has been accomplished through deposition of uniform layers of magnetite/maghemite nanoparticles (diameter ) 6-10 nm) and use of an external magnetic field. The coating of CNTs with magnetic nanoparticles was performed by combining the polymer wrapping and layer-by-layer (LbL) assembly techniques. The particle-coated MWNTs are superparamagnetic and can be aligned at room temperature on any substrate by deposition from an aqueous solution in an external field B ) 0.2 T. The volume magnetization of the particle coated MWNTs is found to be enhanced by 17% compared to the pure particles in a powder indicating that either the adsorption process onto the CNTs changes the particle magnetization, or the MWNTs carry an intrinsic magnetization due to remaining Ni used as a catalyst for the growth process.
Advanced Materials, 2006
... Article first published online: 25 JAN 2006. DOI: 10.1002/adma.200501523. ... Publication His... more ... Article first published online: 25 JAN 2006. DOI: 10.1002/adma.200501523. ... Publication History. Issue published online: 10 FEB 2006; Article first published online: 25 JAN 2006; Manuscript Accepted: 10 OCT 2005; Manuscript Received: 23 JUL 2005. SEARCH. ...
Acs Nano, 2009
Novel colloidal composites have been designed to incorporate multiple functionalities that allow ... more Novel colloidal composites have been designed to incorporate multiple functionalities that allow optical detection, magnetic manipulation, molecular trapping, and thermal response. Such particles are made of gold nanoparticle cores covered by a thin layer of metallic nickel and a poly(N-isopropylacrylamide) (pNIPAM) shell. While the gold cores provide efficient optical response through localized surface plasmon resonances, nickel allows external magnetic manipulation and the pNIPAM shell can be swollen or collapsed as a function of temperature, thus allowing capture and release of various types of molecules.
Advanced Functional Materials, 2008
Journal of Physical Chemistry C, 2007
Advanced Functional Materials, 2008
Chemical Society Reviews, 2008
In this tutorial review, we summarise recent research into the controlled growth of gold nanopart... more In this tutorial review, we summarise recent research into the controlled growth of gold nanoparticles of different morphologies and discuss the various chemical mechanisms that have been proposed to explain anisotropic growth. With the overview and discussion, we intended to select those published procedures that we consider more reliable and promising for synthesis of morphologies of interest. We expect this to be interesting to researchers in the wide variety of fields that can make use of metal nanoparticles.
Angewandte Chemie-international Edition, 2007
Acs Nano, 2010
Within the field of nanotechnology, nanoparticles are one of the most prominent and promising can... more Within the field of nanotechnology, nanoparticles are one of the most prominent and promising candidates for technological applications. Self-assembly of nanoparticles has been identified as an important process where the building blocks spontaneously organize into ordered structures by thermodynamic and other constraints. However, in order to successfully exploit nanoparticle self-assembly in technological applications and to ensure efficient scale-up, a high level of direction and control is required. The present review critically
IEEE Transactions on Consumer Electronics, 2012
We report the direct formation of multiwalled carbon nanotubes (MWNT) by ultrasonication of graph... more We report the direct formation of multiwalled carbon nanotubes (MWNT) by ultrasonication of graphite in dimethylformamide (DMF) upon addition of ferrocene aldehyde (Fc-CHO). The tubular structures appear exclusively at the edges of graphene layers and contain Fe clusters. Fc in conjunction with benzyl aldehyde, or other Fc derivatives, does not induce formation of NT. Higher amounts of Fc-CHO added to the dispersion do not increase significantly MWNT formation. Increasing the temperature reduces the amount of formation of MWNTs and shows the key role of ultrasound-induced cavitation energy. It is concluded that Fc-CHO first reduces the concentration of radical reactive species that slice graphene into small moieties, localizes itself at the edges of graphene, templates the rolling up of a sheet to form a nanoscroll, where it remains trapped, and finally accepts and donates unpaired electron to the graphene edges and converts the less stable scroll into a MWNT. This new methodology matches the long held notion that CNTs are rolled up graphene layers. The proposed mechanism is general and will lead to control the production of carbon nanostructures by simple ultrasonication treatments.
Journal of Materials Chemistry, 2006
... Influence of silver ions on the growth mode of platinum on gold nanorods. Marek Grzelczak, Jo... more ... Influence of silver ions on the growth mode of platinum on gold nanorods. Marek Grzelczak, Jorge Pérez-Juste, Benito Rodríguez-González and Luis M. Liz-Marzán J. Mater. Chem., 2006, 16, 3946-3951. DOI: 10.1039/B606887A ...
methylpyrrolidone were successfully functionalized using the 1,3-dipolar cycloaddition of azometh... more methylpyrrolidone were successfully functionalized using the 1,3-dipolar cycloaddition of azomethine ylides. The amino functional groups attached to graphene sheets were quantified by the Kaiser test. These amino groups selectively bind to gold nanorods, which were introduced as contrast markers for the identification of the graphene reactive sites. The interaction between gold nanorods and functionalized graphene was followed by UV؊vis spectroscopy. The presence of the organic groups was confirmed by X-ray photoelectron spectroscopy and thermogravimetric analysis. The sheets were characterized by transmission electron microscopy, demonstrating the presence of gold nanorods distributed uniformly all over the graphene surface. This observation indicates that reaction has taken place not just at the edges but also at the internal CAC bonds of graphene. Our results identify exfoliated graphene as a considerably more reactive structure than graphite and hence open the possibility to control the functionalization for use as a scaffold in the construction of organized composite nanomaterials.
Anisotropic, magnetic nickel shells were grown on gold nanorods [1] and on carbon nanotubes (CNT)... more Anisotropic, magnetic nickel shells were grown on gold nanorods [1] and on carbon nanotubes (CNT) [2] using Pt nanocrystals as catalysts. We used high resolution transmission electron microscopy (HRTEM) to characterize these well-defined metallic nickel shells.
Langmuir, 2009
We report the formation of porous gold nanoparticles with unusual, angled shapes (such as nanoche... more We report the formation of porous gold nanoparticles with unusual, angled shapes (such as nanocheckmarks) through spontaneous transformation of tellurium sacrificial templates by gradual galvanic replacement. High-resolution electron microscopy studies of intermediate stages reveal interesting information regarding the replacement mechanism, which involves initial "gold island growth" at the edges, and gradual branching to engulf the entire particle templates, resulting in a highly porous structure. Additionally, the high porosity of these novel nanostructures with unusual shapes is demonstrated to provide very high enhancement of the Raman scattering signal from adsorbed molecules.
In this tutorial review, we summarise recent research into the controlled growth of gold nanopart... more In this tutorial review, we summarise recent research into the controlled growth of gold nanoparticles of different morphologies and discuss the various chemical mechanisms that have been proposed to explain anisotropic growth. With the overview and discussion, we intended to select those published procedures that we consider more reliable and promising for synthesis of morphologies of interest. We expect this
Cheminform, 2008
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
methylpyrrolidone were successfully functionalized using the 1,3-dipolar cycloaddition of azometh... more methylpyrrolidone were successfully functionalized using the 1,3-dipolar cycloaddition of azomethine ylides. The amino functional groups attached to graphene sheets were quantified by the Kaiser test. These amino groups selectively bind to gold nanorods, which were introduced as contrast markers for the identification of the graphene reactive sites. The interaction between gold nanorods and functionalized graphene was followed by UV؊vis spectroscopy. The presence of the organic groups was confirmed by X-ray photoelectron spectroscopy and thermogravimetric analysis. The sheets were characterized by transmission electron microscopy, demonstrating the presence of gold nanorods distributed uniformly all over the graphene surface. This observation indicates that reaction has taken place not just at the edges but also at the internal CAC bonds of graphene. Our results identify exfoliated graphene as a considerably more reactive structure than graphite and hence open the possibility to control the functionalization for use as a scaffold in the construction of organized composite nanomaterials.
Journal of Physical Chemistry B, 2005
The alignment of multiwalled carbon nanotubes (MWNTs) has been accomplished through deposition of... more The alignment of multiwalled carbon nanotubes (MWNTs) has been accomplished through deposition of uniform layers of magnetite/maghemite nanoparticles (diameter ) 6-10 nm) and use of an external magnetic field. The coating of CNTs with magnetic nanoparticles was performed by combining the polymer wrapping and layer-by-layer (LbL) assembly techniques. The particle-coated MWNTs are superparamagnetic and can be aligned at room temperature on any substrate by deposition from an aqueous solution in an external field B ) 0.2 T. The volume magnetization of the particle coated MWNTs is found to be enhanced by 17% compared to the pure particles in a powder indicating that either the adsorption process onto the CNTs changes the particle magnetization, or the MWNTs carry an intrinsic magnetization due to remaining Ni used as a catalyst for the growth process.
Advanced Materials, 2006
... Article first published online: 25 JAN 2006. DOI: 10.1002/adma.200501523. ... Publication His... more ... Article first published online: 25 JAN 2006. DOI: 10.1002/adma.200501523. ... Publication History. Issue published online: 10 FEB 2006; Article first published online: 25 JAN 2006; Manuscript Accepted: 10 OCT 2005; Manuscript Received: 23 JUL 2005. SEARCH. ...
Acs Nano, 2009
Novel colloidal composites have been designed to incorporate multiple functionalities that allow ... more Novel colloidal composites have been designed to incorporate multiple functionalities that allow optical detection, magnetic manipulation, molecular trapping, and thermal response. Such particles are made of gold nanoparticle cores covered by a thin layer of metallic nickel and a poly(N-isopropylacrylamide) (pNIPAM) shell. While the gold cores provide efficient optical response through localized surface plasmon resonances, nickel allows external magnetic manipulation and the pNIPAM shell can be swollen or collapsed as a function of temperature, thus allowing capture and release of various types of molecules.
Advanced Functional Materials, 2008
Journal of Physical Chemistry C, 2007
Advanced Functional Materials, 2008
Chemical Society Reviews, 2008
In this tutorial review, we summarise recent research into the controlled growth of gold nanopart... more In this tutorial review, we summarise recent research into the controlled growth of gold nanoparticles of different morphologies and discuss the various chemical mechanisms that have been proposed to explain anisotropic growth. With the overview and discussion, we intended to select those published procedures that we consider more reliable and promising for synthesis of morphologies of interest. We expect this to be interesting to researchers in the wide variety of fields that can make use of metal nanoparticles.
Angewandte Chemie-international Edition, 2007
Acs Nano, 2010
Within the field of nanotechnology, nanoparticles are one of the most prominent and promising can... more Within the field of nanotechnology, nanoparticles are one of the most prominent and promising candidates for technological applications. Self-assembly of nanoparticles has been identified as an important process where the building blocks spontaneously organize into ordered structures by thermodynamic and other constraints. However, in order to successfully exploit nanoparticle self-assembly in technological applications and to ensure efficient scale-up, a high level of direction and control is required. The present review critically