dr hab. Bartłomiej Graczykowski
adiunkt
tel.: +48 61 829 5098
pokój: 212/D
Zainteresowania naukowe
Wykształcenie
Inne informacje
2021 |
Navarro-Urrios, Daniel; Kang, E; Xiao, P; Colombano, M F; Arregui, G; Graczykowski, Bartłomiej; Capuj, N E; Sledzinska, M; Sotomayor-Torres, C M; Fytas, G Optomechanical crystals for spatial sensing of submicron sized particles Scientific Reports, 11 (1), pp. 7829, 2021, ISSN: 2045-2322. Abstract - Links - BibTeX - Tagi: @article{Navarro-Urrios2020, title = {Optomechanical crystals for spatial sensing of submicron sized particles}, author = {Daniel Navarro-Urrios and E Kang and P Xiao and M F Colombano and G Arregui and Bartłomiej Graczykowski and N E Capuj and M Sledzinska and C M Sotomayor-Torres and G Fytas}, url = {https://doi.org/10.1038/s41598-021-87558-4 http://www.nature.com/articles/s41598-021-87558-4}, doi = {10.1038/s41598-021-87558-4}, issn = {2045-2322}, year = {2021}, date = {2021-12-01}, journal = {Scientific Reports}, volume = {11}, number = {1}, pages = {7829}, publisher = {Nature Publishing Group UK}, abstract = {Optomechanical crystal cavities (OMC) have rich perspectives for detecting and indirectly analysing biological particles, such as proteins, bacteria and viruses. In this work we demonstrate the working principle of OMCs operating under ambient conditions as a sensor of submicrometer particles by optically monitoring the frequency shift of thermally activated mechanical modes. The resonator has been specifically designed so that the cavity region supports a particular family of low modal-volume mechanical modes, commonly known as -pinch modes-. These involve the oscillation of only a couple of adjacent cavity cells that are relatively insensitive to perturbations in other parts of the resonator. The eigenfrequency of these modes decreases as the deformation is localized closer to the centre of the resonator. Thus, by identifying specific modes that undergo a frequency shift that amply exceeds the mechanical linewidth, it is possible to infer if there are particles deposited on the resonator, how many are there and their approximate position within the cavity region. OMCs have rich perspectives for detecting and indirectly analysing biological particles, such as proteins, viruses and bacteria.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Optomechanical crystal cavities (OMC) have rich perspectives for detecting and indirectly analysing biological particles, such as proteins, bacteria and viruses. In this work we demonstrate the working principle of OMCs operating under ambient conditions as a sensor of submicrometer particles by optically monitoring the frequency shift of thermally activated mechanical modes. The resonator has been specifically designed so that the cavity region supports a particular family of low modal-volume mechanical modes, commonly known as -pinch modes-. These involve the oscillation of only a couple of adjacent cavity cells that are relatively insensitive to perturbations in other parts of the resonator. The eigenfrequency of these modes decreases as the deformation is localized closer to the centre of the resonator. Thus, by identifying specific modes that undergo a frequency shift that amply exceeds the mechanical linewidth, it is possible to infer if there are particles deposited on the resonator, how many are there and their approximate position within the cavity region. OMCs have rich perspectives for detecting and indirectly analysing biological particles, such as proteins, viruses and bacteria. |
Vasileiadis, Thomas; Varghese, Jeena; Babacic, Visnja; Gomis-Bresco, Jordi; Urrios, Daniel Navarro; Graczykowski, Bartłomiej Progress and perspectives on phononic crystals Journal of Applied Physics, 129 (16), pp. 160901, 2021, ISSN: 0021-8979. @article{Vasileiadis2021, title = {Progress and perspectives on phononic crystals}, author = {Thomas Vasileiadis and Jeena Varghese and Visnja Babacic and Jordi Gomis-Bresco and Daniel Navarro Urrios and Bartłomiej Graczykowski}, url = {https://aip.scitation.org/doi/10.1063/5.0042337}, doi = {10.1063/5.0042337}, issn = {0021-8979}, year = {2021}, date = {2021-04-01}, journal = {Journal of Applied Physics}, volume = {129}, number = {16}, pages = {160901}, publisher = {AIP Publishing LLC}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Coy, Emerson; Babacic, Visnja; Yate, Luis; Załęski, Karol; Kim, Yeonho; Reparaz, Juan Sebastián; Dörling, Bernhard; Graczykowski, Bartłomiej; Iatsunskyi, Igor; Siuzdak, Katarzyna Chemical Engineering Journal, 415 , pp. 128987, 2021, ISSN: 1385-8947. Abstract - Links - BibTeX - Tagi: Carbides, Electrochemical Window, Electrode: Nanocomposite, Hafnium, Tantalum, Thermoelectric, Thin films @article{COY2021128987, title = {Study of nanostructured ultra-refractory Tantalum-Hafnium-Carbide electrodes with wide electrochemical stability window}, author = {Emerson Coy and Visnja Babacic and Luis Yate and Karol Załęski and Yeonho Kim and Juan Sebastián Reparaz and Bernhard Dörling and Bartłomiej Graczykowski and Igor Iatsunskyi and Katarzyna Siuzdak}, url = {https://www.sciencedirect.com/science/article/pii/S1385894721005805}, doi = {https://doi.org/10.1016/j.cej.2021.128987}, issn = {1385-8947}, year = {2021}, date = {2021-01-01}, journal = {Chemical Engineering Journal}, volume = {415}, pages = {128987}, abstract = {Transition metal carbides have gathered increasing attention in energy and electrochemistry applications, mainly due to their high structural and physicochemical properties. Their high refractory properties have made them an ideal candidate coating technology and more recently their electronic similarity to the platinum group has expanded their use to energy and catalysis. Here, we demonstrate that the nanostructuring and stoichiometry control of the highest melting point material to this date (Ta-Hf-C) results in outstanding electrochemical stability. Our results show one of the largest windows of stability of a single component electrode in a broad range pH. These experiments provide a new perspective on the electrochemical, thermoelectric and mechanical behavior of Ta-Hf-C nanocomposites, towards a broad range of applications in energy production, catalysis and analytical chemistry.}, keywords = {Carbides, Electrochemical Window, Electrode: Nanocomposite, Hafnium, Tantalum, Thermoelectric, Thin films}, pubstate = {published}, tppubtype = {article} } Transition metal carbides have gathered increasing attention in energy and electrochemistry applications, mainly due to their high structural and physicochemical properties. Their high refractory properties have made them an ideal candidate coating technology and more recently their electronic similarity to the platinum group has expanded their use to energy and catalysis. Here, we demonstrate that the nanostructuring and stoichiometry control of the highest melting point material to this date (Ta-Hf-C) results in outstanding electrochemical stability. Our results show one of the largest windows of stability of a single component electrode in a broad range pH. These experiments provide a new perspective on the electrochemical, thermoelectric and mechanical behavior of Ta-Hf-C nanocomposites, towards a broad range of applications in energy production, catalysis and analytical chemistry. |
2020 |
Dalvise, Tommaso Marchesi; Harvey, Sean; Hueske, Lisa; Szelwicka, Jolanta; Veith, Lothar; Knowles, Tuomas P J; Kubiczek, Dennis; Flaig, Carolin; Port, Fabian; Gottschalk, Kay-E.; Rosenau, Frank; Graczykowski, Bartłomiej; Fytas, George; Ruggeri, Francesco S; Wunderlich, Katrin; Weil, Tanja Ultrathin Polydopamine Films with Phospholipid Nanodiscs Containing a Glycophorin A Domain Advanced Functional Materials, 30 (8), pp. 2000378, 2020, ISSN: 1616301X. @article{Sledzinska2020b, title = {Ultrathin Polydopamine Films with Phospholipid Nanodiscs Containing a Glycophorin A Domain}, author = {Tommaso Marchesi Dalvise and Sean Harvey and Lisa Hueske and Jolanta Szelwicka and Lothar Veith and Tuomas P J Knowles and Dennis Kubiczek and Carolin Flaig and Fabian Port and Kay-E. Gottschalk and Frank Rosenau and Bartłomiej Graczykowski and George Fytas and Francesco S Ruggeri and Katrin Wunderlich and Tanja Weil}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adfm.201904434 http://doi.wiley.com/10.1002/adfm.202000378}, doi = {10.1002/adfm.202000378}, issn = {1616301X}, year = {2020}, date = {2020-03-01}, journal = {Advanced Functional Materials}, volume = {30}, number = {8}, pages = {2000378}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Graczykowski, Bartłomiej; Vogel, Nicolas; Bley, Karina; Butt, Hans-Jürgen; Fytas, George Nano Letters, 20 (3), pp. 1883–1889, 2020, ISSN: 1530-6984. @article{Sledzinska2020c, title = {Multiband Hypersound Filtering in Two-Dimensional Colloidal Crystals: Adhesion, Resonances, and Periodicity}, author = {Bartłomiej Graczykowski and Nicolas Vogel and Karina Bley and Hans-Jürgen Butt and George Fytas}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adfm.201904434 http://doi.wiley.com/10.1002/adfm.202000378 https://pubs.acs.org/doi/10.1021/acs.nanolett.9b05101}, doi = {10.1021/acs.nanolett.9b05101}, issn = {1530-6984}, year = {2020}, date = {2020-03-01}, journal = {Nano Letters}, volume = {20}, number = {3}, pages = {1883--1889}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Śledzińska, Marianna; Graczykowski, Bartłomiej; Maire, Jeremie; Chavez‐Angel, Emigdio; Sotomayor‐Torres, Clivia M; Alzina, Francesc 2D Phononic Crystals: Progress and Prospects in Hypersound and Thermal Transport Engineering Advanced Functional Materials, 30 (8), pp. 1904434, 2020, ISSN: 1616-301X. @article{Sledzinska2020, title = {2D Phononic Crystals: Progress and Prospects in Hypersound and Thermal Transport Engineering}, author = {Marianna Śledzińska and Bartłomiej Graczykowski and Jeremie Maire and Emigdio Chavez‐Angel and Clivia M Sotomayor‐Torres and Francesc Alzina}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adfm.201904434}, doi = {10.1002/adfm.201904434}, issn = {1616-301X}, year = {2020}, date = {2020-02-01}, journal = {Advanced Functional Materials}, volume = {30}, number = {8}, pages = {1904434}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Babačić, Višnja; Varghese, Jeena; Coy, Emerson; Kang, Eunsoo; Pochylski, Mikołaj; Gapiński, Jacek; Fytas, George; Graczykowski, Bartłomiej Mechanical reinforcement of polymer colloidal crystals by supercritical fluids Journal of Colloid and Interface Science, 579 , pp. 786 - 793, 2020, ISSN: 0021-9797. Abstract - Links - BibTeX - Tagi: Brillouin light scattering, Colloidal crystals, Phononic crystals, Photonic crystals, Plasticization @article{BABACIC2020786, title = {Mechanical reinforcement of polymer colloidal crystals by supercritical fluids}, author = {Višnja Babačić and Jeena Varghese and Emerson Coy and Eunsoo Kang and Mikołaj Pochylski and Jacek Gapiński and George Fytas and Bartłomiej Graczykowski}, url = {http://www.sciencedirect.com/science/article/pii/S0021979720308493}, doi = {https://doi.org/10.1016/j.jcis.2020.06.104}, issn = {0021-9797}, year = {2020}, date = {2020-01-01}, journal = {Journal of Colloid and Interface Science}, volume = {579}, pages = {786 - 793}, abstract = {Colloidal crystals realized by self-assembled polymer nanoparticles have prominent attraction as a platform for various applications from assembling photonic and phononic crystals, acoustic metamaterials to coating applications. However, the fragility of these systems limits their application horizon. In this work the uniform mechanical reinforcement and tunability of 3D polystyrene colloidal crystals by means of cold soldering are reported. This structural strengthening is achieved by high pressure gas (N2 or Ar) plasticization at temperatures well below the glass transition. Brillouin light scattering is employed to monitor in-situ the mechanical vibrations of the crystal and thereby determine preferential pressure, temperature and time ranges for soldering, i.e. formation of physical bonding among the nanoparticles while maintaining the shape and translational order. This low-cost method is potentially useful for fabrication and tuning of durable devices including applications in photonics, phononics, acoustic metamaterials, optomechanics, surface coatings and nanolithography.}, keywords = {Brillouin light scattering, Colloidal crystals, Phononic crystals, Photonic crystals, Plasticization}, pubstate = {published}, tppubtype = {article} } Colloidal crystals realized by self-assembled polymer nanoparticles have prominent attraction as a platform for various applications from assembling photonic and phononic crystals, acoustic metamaterials to coating applications. However, the fragility of these systems limits their application horizon. In this work the uniform mechanical reinforcement and tunability of 3D polystyrene colloidal crystals by means of cold soldering are reported. This structural strengthening is achieved by high pressure gas (N2 or Ar) plasticization at temperatures well below the glass transition. Brillouin light scattering is employed to monitor in-situ the mechanical vibrations of the crystal and thereby determine preferential pressure, temperature and time ranges for soldering, i.e. formation of physical bonding among the nanoparticles while maintaining the shape and translational order. This low-cost method is potentially useful for fabrication and tuning of durable devices including applications in photonics, phononics, acoustic metamaterials, optomechanics, surface coatings and nanolithography. |
Vasileiadis, Thomas; Zhang, Heng; Wang, Hai; Bonn, Mischa; Fytas, George; Graczykowski, Bartłomiej Frequency-domain study of nonthermal gigahertz phonons reveals Fano coupling to charge carriers Science Advances, 6 (51), 2020, ISSN: 23752548. Abstract - Links - BibTeX - Tagi: @article{Vasileiadis2020, title = {Frequency-domain study of nonthermal gigahertz phonons reveals Fano coupling to charge carriers}, author = {Thomas Vasileiadis and Heng Zhang and Hai Wang and Mischa Bonn and George Fytas and Bartłomiej Graczykowski}, doi = {10.1126/SCIADV.ABD4540}, issn = {23752548}, year = {2020}, date = {2020-01-01}, journal = {Science Advances}, volume = {6}, number = {51}, abstract = {Telecommunication devices exploit hypersonic gigahertz acoustic phonons to mediate signal processing with microwave radiation, and charge carriers to operate various microelectronic components. Potential interactions of hypersound with charge carriers can be revealed through frequency- and momentum-resolved studies of acoustic phonons in photoexcited semiconductors. Here, we present an all-optical method for excitation and frequency-, momentum-, and space-resolved detection of gigahertz acoustic waves in a spatially confined model semiconductor. Lamb waves are excited in a bare silicon membrane using femtosecond optical pulses and detected with frequency-domain micro-Brillouin light spectroscopy. The population of photoexcited gigahertz phonons displays a hundredfold enhancement as compared with thermal equilibrium. The phonon spectra reveal Stokes–anti-Stokes asymmetry due to propagation, and strongly asymmetric Fano resonances due to coupling between the electron-hole plasma and the photoexcited phonons. This work lays the foundation for studying hypersonic signals in nonequilibrium conditions and, more generally, phonon-dependent phenomena in photoexcited nanostructures.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Telecommunication devices exploit hypersonic gigahertz acoustic phonons to mediate signal processing with microwave radiation, and charge carriers to operate various microelectronic components. Potential interactions of hypersound with charge carriers can be revealed through frequency- and momentum-resolved studies of acoustic phonons in photoexcited semiconductors. Here, we present an all-optical method for excitation and frequency-, momentum-, and space-resolved detection of gigahertz acoustic waves in a spatially confined model semiconductor. Lamb waves are excited in a bare silicon membrane using femtosecond optical pulses and detected with frequency-domain micro-Brillouin light spectroscopy. The population of photoexcited gigahertz phonons displays a hundredfold enhancement as compared with thermal equilibrium. The phonon spectra reveal Stokes–anti-Stokes asymmetry due to propagation, and strongly asymmetric Fano resonances due to coupling between the electron-hole plasma and the photoexcited phonons. This work lays the foundation for studying hypersonic signals in nonequilibrium conditions and, more generally, phonon-dependent phenomena in photoexcited nanostructures. |
Kasprzak, Maciej; Sledzinska, Marianna; Zaleski, Karol; Iatsunskyi, Igor; Alzina, Francesc; Volz, Sebastian; Torres, Clivia Sotomayor M; Graczykowski, Bartłomiej High-temperature silicon thermal diode and switch Nano Energy, 78 (July), 2020, ISSN: 22112855. Abstract - Links - BibTeX - Tagi: High temperatures, Raman thermometry, Thermal diode, Thermal rectification, Thermal switch, Thermoelectrics @article{Kasprzak2020, title = {High-temperature silicon thermal diode and switch}, author = {Maciej Kasprzak and Marianna Sledzinska and Karol Zaleski and Igor Iatsunskyi and Francesc Alzina and Sebastian Volz and Clivia M Sotomayor Torres and Bartłomiej Graczykowski}, doi = {10.1016/j.nanoen.2020.105261}, issn = {22112855}, year = {2020}, date = {2020-01-01}, journal = {Nano Energy}, volume = {78}, number = {July}, publisher = {Elsevier Ltd}, abstract = {A thermal rectifier/diode is a nonreciprocal element or system that enables preferential heat transport in one direction. In this work we demonstrate a single-material thermal diode operating at high temperatures. The diode is made of nanostructured silicon membranes exhibiting spatially and temperature-dependent thermal conductivity and, therefore, falling into the category of spatially asymmetric, nonlinear nonreciprocal systems. We used an all-optical state-of-the-art experimental technique to prove rectification along rigorous criteria of the phenomenon. Using sub-milliwatt power we achieve rectification of about 14%. In addition, we demonstrate air-triggered thermal switching and passive cooling. Our findings provide a CMOS-compatible platform for heat rectification and applications in energy harvesting, thermal insulation and cooling, as well as sensing and potentially thermal logic.}, keywords = {High temperatures, Raman thermometry, Thermal diode, Thermal rectification, Thermal switch, Thermoelectrics}, pubstate = {published}, tppubtype = {article} } A thermal rectifier/diode is a nonreciprocal element or system that enables preferential heat transport in one direction. In this work we demonstrate a single-material thermal diode operating at high temperatures. The diode is made of nanostructured silicon membranes exhibiting spatially and temperature-dependent thermal conductivity and, therefore, falling into the category of spatially asymmetric, nonlinear nonreciprocal systems. We used an all-optical state-of-the-art experimental technique to prove rectification along rigorous criteria of the phenomenon. Using sub-milliwatt power we achieve rectification of about 14%. In addition, we demonstrate air-triggered thermal switching and passive cooling. Our findings provide a CMOS-compatible platform for heat rectification and applications in energy harvesting, thermal insulation and cooling, as well as sensing and potentially thermal logic. |
2019 |
Śledzińska, Marianna; Graczykowski, Bartłomiej; Marie, Jeremie; Chavez-Angel, Emigdio; Sotomayor-Torres, Clivia M; Alzina, Francesc 2D Phononic Crystals: Progress and Prospects in Hypersound and Thermal Transport Engineering Advanced Functional Materials, pp. 1904434, 2019. Abstract - Links - BibTeX - Tagi: brillouin @article{Śledzińska2019, title = {2D Phononic Crystals: Progress and Prospects in Hypersound and Thermal Transport Engineering}, author = {Marianna Śledzińska and Bartłomiej Graczykowski and Jeremie Marie and Emigdio Chavez-Angel and Clivia M. Sotomayor-Torres and Francesc Alzina}, doi = {10.1002/adfm.201904434}, year = {2019}, date = {2019-09-11}, journal = {Advanced Functional Materials}, pages = {1904434}, abstract = {The central concept in phononics is the tuning of the phonon dispersion relation, or phonon engineering, which provides a means of controlling related properties such as group velocity or phonon interactions and, therefore, phonon propagation, in a wide range of frequencies depending on the geometries and sizes of the materials. Phononics exploits the present state of the art in nanofabrication to tailor dispersion relations in the range of GHz for the control of elastic waves/phonons propagation with applications toward new information technology concepts with phonons as state variable. Moreover, phonons provide an adaptable approach for supporting a coherent coupling between different state variables, and the development of nanoscale optomechanical systems during the last decade attests this prospect. The most extended approach to manipulate the phonon dispersion relation is introducing an artificial periodic modulation of the elastic properties, which is referred to as phononic crystal (PnC). Herein, the focus is on the recent experimental achievements in the fabrication and application of 2D PnCs enabling the modification of the dispersion relation of surface and membrane modes, and presenting phononic bandgaps, waveguiding, and confinement in the hypersonic regime. Furthermore, these artificial materials offer the potential of modifying and controlling the heat flow to enable new schemes in thermal management.}, keywords = {brillouin}, pubstate = {published}, tppubtype = {article} } The central concept in phononics is the tuning of the phonon dispersion relation, or phonon engineering, which provides a means of controlling related properties such as group velocity or phonon interactions and, therefore, phonon propagation, in a wide range of frequencies depending on the geometries and sizes of the materials. Phononics exploits the present state of the art in nanofabrication to tailor dispersion relations in the range of GHz for the control of elastic waves/phonons propagation with applications toward new information technology concepts with phonons as state variable. Moreover, phonons provide an adaptable approach for supporting a coherent coupling between different state variables, and the development of nanoscale optomechanical systems during the last decade attests this prospect. The most extended approach to manipulate the phonon dispersion relation is introducing an artificial periodic modulation of the elastic properties, which is referred to as phononic crystal (PnC). Herein, the focus is on the recent experimental achievements in the fabrication and application of 2D PnCs enabling the modification of the dispersion relation of surface and membrane modes, and presenting phononic bandgaps, waveguiding, and confinement in the hypersonic regime. Furthermore, these artificial materials offer the potential of modifying and controlling the heat flow to enable new schemes in thermal management. |
Graczykowski, Bartłomiej; Gueddida, A; Djafari-Rouhani, B; Butt, H -J; Fytas, Georg Physical Review B, 99 (16), 2019. Abstract - Links - BibTeX - Tagi: @article{Graczykowski2019, title = {Brillouin light scattering under one-dimensional confinement: Symmetry and interference self-canceling}, author = {Bartłomiej Graczykowski and A Gueddida and B Djafari-Rouhani and H -J Butt and Georg Fytas}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85065496617&doi=10.1103%2fPhysRevB.99.165431&partnerID=40&md5=fc7596c288a1a9ecba8176296c150eac}, doi = {10.1103/PhysRevB.99.165431}, year = {2019}, date = {2019-01-01}, journal = {Physical Review B}, volume = {99}, number = {16}, abstract = {We present the spontaneous Brillouin light scattering (BLS) under simultaneous one-dimensional confinement of sound and light and show that the photon-phonon coupling results from nontrivial interplay of the photoelastic and moving-interface effects. We reveal two types of BLS self-canceling: governed by mode symmetry and driven by destructive interference of the two effects. We show that the latter can be adjusted by the light polarization and phonon wave number. Furthermore, we present a measurement of the shear-horizontal waves in thin membranes. © 2019 American Physical Society.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We present the spontaneous Brillouin light scattering (BLS) under simultaneous one-dimensional confinement of sound and light and show that the photon-phonon coupling results from nontrivial interplay of the photoelastic and moving-interface effects. We reveal two types of BLS self-canceling: governed by mode symmetry and driven by destructive interference of the two effects. We show that the latter can be adjusted by the light polarization and phonon wave number. Furthermore, we present a measurement of the shear-horizontal waves in thin membranes. © 2019 American Physical Society. |
Kang, E; Graczykowski, Bartłomiej; Jonas, U; Christie, D; Gray, L A G; Cangialosi, D; Priestley, R D; Fytas, Georg Macromolecules, 52 (14), pp. 5399-5406, 2019. Abstract - Links - BibTeX - Tagi: @article{Kang20195399, title = {Shell Architecture Strongly Influences the Glass Transition, Surface Mobility, and Elasticity of Polymer Core-Shell Nanoparticles}, author = {E Kang and Bartłomiej Graczykowski and U Jonas and D Christie and L A G Gray and D Cangialosi and R D Priestley and Georg Fytas}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85070272667&doi=10.1021%2facs.macromol.9b00766&partnerID=40&md5=2dcd70191d0df0d80f2a608e2ce143cc}, doi = {10.1021/acs.macromol.9b00766}, year = {2019}, date = {2019-01-01}, journal = {Macromolecules}, volume = {52}, number = {14}, pages = {5399-5406}, abstract = {Despite the growing application of nanostructured polymeric materials, there still remains a large gap in our understanding of polymer mechanics and thermal stability under confinement and near polymer-polymer interfaces. In particular, the knowledge of polymer nanoparticle thermal stability and mechanics is of great importance for their application in drug delivery, phononics, and photonics. Here, we quantified the effects of a polymer shell layer on the modulus and glass-transition temperature (Tg) of polymer core-shell nanoparticles via Brillouin light spectroscopy and modulated differential scanning calorimetry, respectively. Nanoparticles consisting of a polystyrene (PS) core and shell layers of poly(n-butyl methacrylate) (PBMA) were characterized as model systems. We found that the high Tg of the PS core was largely unaffected by the presence of an outer polymer shell, whereas the lower Tg of the PBMA shell layer decreased with increasing PBMA thickness. The surface mobility was revealed at a temperature about 15 K lower than the Tg of the PBMA shell layer. Overall, the modulus of the core-shell nanoparticles decreased with increasing PBMA shell layer thickness. These results suggest that the nanoparticle modulus and Tg can be tuned independently through the control of nanoparticle composition and architecture. © 2019 American Chemical Society.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Despite the growing application of nanostructured polymeric materials, there still remains a large gap in our understanding of polymer mechanics and thermal stability under confinement and near polymer-polymer interfaces. In particular, the knowledge of polymer nanoparticle thermal stability and mechanics is of great importance for their application in drug delivery, phononics, and photonics. Here, we quantified the effects of a polymer shell layer on the modulus and glass-transition temperature (Tg) of polymer core-shell nanoparticles via Brillouin light spectroscopy and modulated differential scanning calorimetry, respectively. Nanoparticles consisting of a polystyrene (PS) core and shell layers of poly(n-butyl methacrylate) (PBMA) were characterized as model systems. We found that the high Tg of the PS core was largely unaffected by the presence of an outer polymer shell, whereas the lower Tg of the PBMA shell layer decreased with increasing PBMA thickness. The surface mobility was revealed at a temperature about 15 K lower than the Tg of the PBMA shell layer. Overall, the modulus of the core-shell nanoparticles decreased with increasing PBMA shell layer thickness. These results suggest that the nanoparticle modulus and Tg can be tuned independently through the control of nanoparticle composition and architecture. © 2019 American Chemical Society. |
2011 |
Graczykowski, Bartłomiej; Dobek, Andrzej Iron--dextran complex: Geometrical structure and magneto-optical features Journal of colloid and interface science, 363 (2), pp. 551–556, 2011. BibTeX - Tagi: @article{graczykowski2011iron, title = {Iron--dextran complex: Geometrical structure and magneto-optical features}, author = {Bartłomiej Graczykowski and Andrzej Dobek}, year = {2011}, date = {2011-01-01}, journal = {Journal of colloid and interface science}, volume = {363}, number = {2}, pages = {551--556}, publisher = {Elsevier}, keywords = {}, pubstate = {published}, tppubtype = {article} } |