1. |
Kaczmarek A., Denis P., Krajewski M., Mościcki T., Małolepszy A.♦, Hoffman J., Improved laser ablation method for the production of luminescent carbon particles in liquids,
Materials, ISSN: 1996-1944, DOI: 10.3390/ma14092365, Vol.14, No.9, pp.2365-1-17, 2021Abstract: An improved method for the production of luminescent carbon nanoparticles is proposed in this work. The new method overcomes the disadvantages of commonly used approaches. It involves two-stage laser ablation in water and in aqueous solutions, where the first stage is the laser ablation of a graphite target and the second is the shredding of particles produced in the first step. The two-stage method offers the optimization of the laser pulse fluence for the performance of each process. It was found that the two-stage process of laser ablation allows producing photoluminescent carbon structures in pure water. The additional reagent may be added either in the first or second stage. The first stage performed in pure water allows avoiding the contamination of the target. Moreover, it simplifies the identification of the origin of photoluminescence. Two synthesis routes for the preparation of carbon nanoparticles by the proposed method using pure water as well as urea aqueous solution are investigated. It was found that the use of urea as a reagent results in luminescence properties similar to those obtained with other more hazardous amine-based reagents. The influence of the synthesis approach and process parameters on the structural and luminescent properties of nanoparticles is also explored in this work. Keywords: pulsed laser ablation in liquid, carbon nanoparticles, photoluminescent particles Affiliations:
Kaczmarek A. | - | IPPT PAN | Denis P. | - | IPPT PAN | Krajewski M. | - | IPPT PAN | Mościcki T. | - | IPPT PAN | Małolepszy A. | - | Warsaw University of Technology (PL) | Hoffman J. | - | IPPT PAN |
| |
2. |
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, 2021Abstract: 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) |
| |
3. |
Krajewski M., Liou S.C.♦, Chiou W.A.♦, Tokarczyk M.♦, Małolepszy A.♦, Płocińska M.♦, Witecka A., Lewińska S.♦, Ślawska-Waniewska A.♦, Amorphous FexCo1–x wire-like nanostructures manufactured through surfactant-free magnetic-field-induced synthesis,
Crystal Growth and Design, ISSN: 1528-7483, DOI: 10.1021/acs.cgd.0c00070, Vol.20, No.5, pp.3208-3216, 2020Abstract: So far, it has been proven that the magnetic-field-induced (MFI) synthesis is a process which mainly leads to the formation of magnetic metallic one-dimensional nanostructures. Taking advantage of this method, the new procedures which allow manufacture of the magnetic bimetallic iron–cobalt wire-like nanochains with Fe0.75 Co0.25, Fe0.50 Co0.50, and Fe0.25 Co0.75 compositions are demonstrated in this work. They were produced through a simple one-step magnetic-field-induced (MFI) chemical co-reduction of three different mixtures containing a proper amount of Fe2+ and Co2+ ions with aqueous sodium borohydride solution as the reducing agent. The synthesis process was carried out at room temperature without the use of templates, surfactants, complexing agents, and organic solvents. The morphological and structural studies indicated that all as-prepared materials were amorphous, and they were composed of nanoparticles aligned in almost straight chains. Moreover, they revealed the core–shell structures with bimetallic alloy cores containing desired iron-to-cobalt ratios and very thin oxide shells. Furthermore, the obtained nanostructures behaved as ferromagnetic materials. Their magnetic properties were correlated with their structural properties and chemical compositions. It was observed that their saturation magnetization decreased significantly with increasing content of cobalt in the chains, whereas the variation of their coercivity was less pronounced. Affiliations:
Krajewski M. | - | IPPT PAN | Liou S.C. | - | University of Maryland (US) | Chiou W.A. | - | University of Maryland (US) | Tokarczyk M. | - | University of Warsaw (PL) | Małolepszy A. | - | Warsaw University of Technology (PL) | Płocińska M. | - | Warsaw University of Technology (PL) | Witecka A. | - | IPPT PAN | Lewińska S. | - | Institute of Physics, Polish Academy of Sciences (PL) | Ślawska-Waniewska A. | - | other affiliation |
| |
4. |
Krajewski M., Tokarczyk M.♦, Stefaniuk T.♦, Słomińska H., Małolepszy A.♦, Kowalski G.♦, Lewińska S.♦, Ślawska-Waniewska A.♦, Magnetic-field-induced synthesis of amorphous iron-nickel wire-like nanostructures,
MATERIALS CHEMISTRY AND PHYSICS, ISSN: 0254-0584, DOI: 10.1016/j.matchemphys.2020.122812, Vol.246, pp.122812-1-7, 2020Abstract: Manufacturing process of wire-like binary or ternary metal nanoalloys applying the magnetic-field-induced (MFI) synthesis is still a challenging task. Hence, this work demonstrates for the first time how to produce the iron-nickel wire-like nanostruc-tures with Fe0.75Ni0.25, Fe0.5Ni0.5 and Fe0.25Ni0.75 compositions. In a contrary to the previously reported synthesis of the Fe-Ni wire-like nanomaterials, this process has been carried out at room temperature without employment of templates, surfactants, organic solvents, and other chemical additives. The as-prepared samples exhibit specific structures with the amorphous bimetallic alloy cores covered by thin amorphous oxide shells. Moreover, they are composed of nanoparticles which are aligned in nearly linear chains. The Fe-Ni samples are ferromagnetic materials. Their coercivity values and saturation magnetizations depend on chemical compositions and dimensions of the investigated chains. The highest saturation magnetization and the lowest coercivity is found for the material with the lowest content of nickel and vice versa. Keywords: amorphous materials, Fe–Ni chains, magnetic-field-induced synthesis, magnetic materials, wire-like nanostructure Affiliations:
Krajewski M. | - | IPPT PAN | Tokarczyk M. | - | University of Warsaw (PL) | Stefaniuk T. | - | University of Warsaw (PL) | Słomińska H. | - | IPPT PAN | Małolepszy A. | - | Warsaw University of Technology (PL) | Kowalski G. | - | University of Warsaw (PL) | Lewińska S. | - | Institute of Physics, Polish Academy of Sciences (PL) | Ślawska-Waniewska A. | - | other affiliation |
| |
5. |
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, 2018Abstract: 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 |
| |
6. |
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, 2017Abstract: 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 |
| |
7. |
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, 2017Abstract: 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) |
| |
8. |
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, 2015Abstract: 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) |
| |
9. |
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, 2015Abstract: 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) |
| |