Partner: Leszek Stobiński

Warsaw University of Technology (PL)

Recent publications
1.Kaczmarek A., Hoffman J., Morgiel J., Mościcki T., Stobiński L., Szymański Z., Małolepszy A., Luminescent carbon dots synthesized by the laser ablation of graphite in polyethylenimine and ethylenediamine, Materials, ISSN: 1996-1944, DOI: 10.3390/ma14040729, Vol.14, No.4, pp.729-1-13, 2021
Abstract:

Fluorescent carbon dots (CDs) synthesized by pulsed laser ablation in liquid (PLAL) are still interesting materials due to their possible applications. However, unlike CDs produced by the hydrothermal method, CDs produced the synthesis products by the PLAL method were never separated by dialysis, which differentiates the synthesis products and allows the identification of the main source of fluorescence. In this work, the synthesis of fluorescent carbon dots (CDs) was performed by nanosecond laser ablation of a graphite target immersed in polyethyleneimine (PEI) and ethylenediamine (EDA), and the synthesis products were separated by dialysis. The results of optical measurements showed that the main source of luminescence of the obtained nanostructures are fluorescent particles or quasi-molecular fluorophores created in the ablation process. In the case of ablation in PEI, most of the produced molecular fluorophores are associated with carbogenic nanostructures, while in the case of EDA, free fluorescent molecules dominate.

Keywords:

carbon dots, photoluminescence, laser ablation

Affiliations:
Kaczmarek A.-IPPT PAN
Hoffman J.-IPPT PAN
Morgiel J.-Institute of Metallurgy and Materials Science, Polish Academy of Sciences (PL)
Mościcki T.-IPPT PAN
Stobiński L.-Warsaw University of Technology (PL)
Szymański Z.-IPPT PAN
Małolepszy A.-Warsaw University of Technology (PL)
2.Małolepszy A., Błoński S., Chrzanowska-Giżyńska J., Wojasiński M., Płociński T., Stobiński L., Szymański Z., Fluorescent carbon and graphene oxide nanoparticles synthesized by the laser ablation in liquid, APPLIED PHYSICS A-MATERIALS SCIENCE AND PROCESSING, ISSN: 0947-8396, DOI: 10.1007/s00339-018-1711-5, Vol.124, pp.282-1-7, 2018
Abstract:

The results of synthesis of the fluorescent carbon dots (CDots) from graphite target and reduced graphene oxide (rGO) nanoparticles performed by the nanosecond laser ablation in polyethylene glycol 200 (PEG200) are shown. Two-step laser irradiation (first graphite target, next achieved suspension) revealed a very effective production of CDots. However, the ablation in PEG appeared to be effective with 1064 nm laser pulse in contrast to the ablation with 355 nm laser pulse. In the case of rGO nanoparticles similar laser irradiation procedure was less efficient. In both cases, received nanoparticles exhibited strong, broadband photoluminescence with a maximum dependent on the excitation wavelength. The size distribution for obtained CDots was evaluated using the DLS technique and HRTEM images. The results from both methods show quite good agreement in nanoparticle size estimation although the DLS method slightly overestimates nanoparticle's diameter

Affiliations:
Małolepszy A.-Warsaw University of Technology (PL)
Błoński S.-IPPT PAN
Chrzanowska-Giżyńska J.-IPPT PAN
Wojasiński M.-Warsaw University of Technology (PL)
Płociński T.-Warsaw University of Technology (PL)
Stobiński L.-Warsaw University of Technology (PL)
Szymański Z.-IPPT PAN
3.Krajewski M., Lee P.H., Wu S.H., Brzózka K., Małolepszy A., Stobiński L., Tokarczyk M., Kowalski G., Wąsik D., Nanocomposite composed of multiwall carbon nanotubes covered by hematite nanoparticles as anode material for Li-ion batteries, Electrochimica Acta, ISSN: 0013-4686, DOI: 10.1016/j.electacta.2017.01.051, Vol.228, pp.82-90, 2017
Abstract:

This work describes the detailed studies performed on the nanocomposite composed of chemically-modified multiwall carbon nanotubes covered by hematite nanoparticles which diameters vary from 10 nm to 70 nm. This nanomaterial was fabricated in two-steps facile chemical synthesis and was characterized with the use of several experimental techniques, such as: thermogravimetric analysis, differential thermal analysis, Raman spectroscopy, X-ray diffraction, and transmission Mössbauer spectroscopy in order to determine its structure precisely. Moreover, the investigated nanocomposite was tested as an anode material of Li-ion batteries. Its cycling performance was stable during 40 cycles, while its capacity was retained at the level of 330 and 230 mAh/g at the discharge/charge rate of 25 and 200 mA/g, respectively.

Keywords:

anode material, hematite, Li-ion battery, multiwall carbon nanotube, nanocomposite

Affiliations:
Krajewski M.-IPPT PAN
Lee P.H.-Tatung University (TW)
Wu S.H.-Tatung University (TW)
Brzózka K.-University of Technology and Humanities in Radom (PL)
Małolepszy A.-Warsaw University of Technology (PL)
Stobiński L.-Warsaw University of Technology (PL)
Tokarczyk M.-University of Warsaw (PL)
Kowalski G.-University of Warsaw (PL)
Wąsik D.-other affiliation
4.Hoffman J., Chrzanowska J., Mościcki T., Radziejewska J., Stobiński L., Szymański Z., Plasma generated during underwater pulsed laser processing, APPLIED SURFACE SCIENCE, ISSN: 0169-4332, DOI: 10.1016/j.apsusc.2017.01.185, Vol.417, pp.130-135, 2017
Abstract:

The plasma induced during underwater pulsed laser ablation of graphite is studied both experimentally and theoretically. The results of the experiment show that the maximum plasma temperature of 25000 K is reached 20 ns from the beginning of the laser pulse and decreases to 6500 K after 1000 ns. The observed OH absorption band shows that the plasma plume is surrounded by the thin layer of dissociated water vapour at a temperature around 5500 K. The hydrodynamic model applied shows similar maximum plasma temperature at delay times between 14 ns and 30 ns. The calculations show also that already at 14th ns, the plasma electron density reaches 0.97·1027 m−3, which is the critical density for 1064 nm radiation. At the same time the plasma pressure is 2 GPa, which is consisted with earlier measurements of the peak pressure exerted on a target in similar conditions.

Keywords:

underwater laser processing, pulsed laser ablation in liquid, laser induced plasma, numerical modelling

Affiliations:
Hoffman J.-IPPT PAN
Chrzanowska J.-IPPT PAN
Mościcki T.-IPPT PAN
Radziejewska J.-IPPT PAN
Stobiński L.-Warsaw University of Technology (PL)
Szymański Z.-IPPT PAN
5.Brzózka K., Krajewski M., Małolepszy A., Stobiński L., Szumiata T., Górka B., Gawroński M., Wasik D., Phase Analysis of Magnetic Inclusions in Nanomaterials Based on Multiwall Carbon Nanotubes, ACTA PHYSICA POLONICA A, ISSN: 0587-4246, DOI: 10.12693/APhysPolA.131.863, Vol.131, No.4, pp.863-865, 2017
Abstract:

Functionalized multiwall carbon nanotubes as well as nanocomposite based on that material covered by nanoparticles composed of iron oxides were the subject of investigations. In order to identify all iron-bearing phases including those reported on the base of previous X-ray diffraction measurements, the transmission Mössbauer spectroscopy was utilized. The experiments were carried out both at room temperature and also at low temperatures. It was stated that in the investigated nanotubes some impurities were present, originating from the catalyst remains, in form of Fe–C and -Fe nanoparticles. The Mössbauer spectra collected for the nanocomposite showed a complex shape characteristic of temperature relaxations. The following subspectra related to iron-based phases were identified: sextet attributed to hematite, with hyperfine magnetic field reduced due to the temperature relaxations, sextet corresponding to iron carbide as well as two doublets linked to superparamagnetic hematite and ferrihydrites.

Keywords:

Mossbauer spectroscopy, multiwall carbon nanotubes, phase transition

Affiliations:
Brzózka K.-University of Technology and Humanities in Radom (PL)
Krajewski M.-IPPT PAN
Małolepszy A.-Warsaw University of Technology (PL)
Stobiński L.-Warsaw University of Technology (PL)
Szumiata T.-other affiliation
Górka B.-other affiliation
Gawroński M.-other affiliation
Wasik D.-University of Warsaw (PL)
6.Chrzanowska J., Hoffman J., Małolepszy A., Mazurkiewicz M., Kowalewski T.A., Szymański Z., Stobiński L., Synthesis of carbon nanotubes by the laser ablation method: Effect of laser wavelength, PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS, ISSN: 0370-1972, DOI: 10.1002/pssb.201451614, Vol.252, No.8, pp.1860-1867, 2015
Abstract:

The effect of laser wavelength on single-wall carbon nanotubes synthesis yield and their properties was studied. A double-pulse Nd:YAG laser, working at a wavelength of 355 or 1064 nm, was used for carbon nanotubes production. The synthesized carbon nanotubes (CNTs) were investigated using the SEM/STEM microscopy and Raman spectroscopy. The results show that the useful range of UV laser radiation fluence is narrower and the properties of synthesized CNTs depend much more on the laser fluence than in the case of infrared laser radiation.

Keywords:

carbon nanotubes, laser radiation fluence, pulsed laser vaporization, Raman spectra

Affiliations:
Chrzanowska J.-IPPT PAN
Hoffman J.-IPPT PAN
Małolepszy A.-Warsaw University of Technology (PL)
Mazurkiewicz M.-other affiliation
Kowalewski T.A.-IPPT PAN
Szymański Z.-IPPT PAN
Stobiński L.-Warsaw University of Technology (PL)
7.Krajewski M., Małolepszy A., Stobiński L., Lewińska S., Ślawska-Waniewska A., Tokarczyk M., Kowalski G., Borysiuk J., Wasik D., Preparation and Characterization of Hematite-Multiwall Carbon Nanotubes Nanocomposite, Journal of Superconductivity and Novel Magnetism, ISSN: 1557-1939, DOI: 10.1007/s10948-014-2794-7, Vol.28, No.3, pp.901-904, 2015
Abstract:

The aim of this work is to study the preparation and characterization of a new nanocomposite which consists of chemically-modified multiwall carbon nanotubes covered by randomly-deposited nanoparticles of hematite. The morphology, structural and physical properties of the investigated nanomaterial were determined by means of transmission electron microscopy, X-ray diffraction and vibrating sample magnetometry at ambient conditions. The presence of residual catalyst nanospheres inside multiwall carbon nanotubes was confirmed by transmission electron microscopy. The signal coming from this contamination was under the detection limit of X-ray diffractometer, therefore it was not registered.

Keywords:

Hematite, Multiwall carbon nanotubes, CVD, TEM, XRD, VSM

Affiliations:
Krajewski M.-other affiliation
Małolepszy A.-Warsaw University of Technology (PL)
Stobiński L.-Warsaw University of Technology (PL)
Lewińska S.-Institute of Physics, Polish Academy of Sciences (PL)
Ślawska-Waniewska A.-other affiliation
Tokarczyk M.-University of Warsaw (PL)
Kowalski G.-University of Warsaw (PL)
Borysiuk J.-University of Warsaw (PL)
Wasik D.-University of Warsaw (PL)

Conference abstracts
1.Chrzanowska J., Błoński S., Hoffman J., Małolepszy A.G., Stobiński L.A., Trykowski G., Szymański Z., Carbon nanoparticles synthesized by the laser ablation in liquid, COLA 2017, International Conference on Laser Ablation, 2017-09-03/09-08, Marseille (FR), pp.286-286, 2017
2.Krajewski M., Lee P.H., Wu S.H., Brzózka K., Małolepszy A., Stobiński L., Wasik D., Wielościenne nanorurki węglowe pokryte hematytem jako materiał anodowy w bateriach litowojonowych, V Ogólnopolska Konferencja Pomiędzy Naukami Zjazd Fizyków i Chemików, 2016-09-16/09-16, Chorzów (PL), No.C8, pp.38, 2016
3.Chrzanowska J., Hoffman J., Kowalewski T.A., Małolepszy A., Mazurkiewicz M., Stobiński L., Szymański Z., Synthesis of Carbon Nanotubes by Laser Ablation Method, KKNM, 4th National Conference on Nano- and Micromechanics, 2014-07-08/07-10, Wrocław (PL), pp.117-118, 2014
Keywords:

laser ablation, graphite, carbon nanotubes

Affiliations:
Chrzanowska J.-IPPT PAN
Hoffman J.-IPPT PAN
Kowalewski T.A.-IPPT PAN
Małolepszy A.-Warsaw University of Technology (PL)
Mazurkiewicz M.-other affiliation
Stobiński L.-Warsaw University of Technology (PL)
Szymański Z.-IPPT PAN
4.Hoffman J., Małolepszy A., Mazurkiewicz M., Stobiński L., Szymański Z., Carbon nanotubes synthesis by the Nd: YAG laser ablation process, III National Conference of Nano and Micromechanics, 2012-07-04/07-06, Warszawa (PL), pp.121-122, 2012