Publications by authors named "Kamil Krawczyk"

Article Synopsis
  • The study focuses on how isomerisation in photochromic spirocompounds affects their functionality, particularly in crystalline forms.
  • Advanced femtosecond spectroscopy shows that when crystalline spiropyran is excited with a 266 nm pulse, rapid bond breaking and isomerisation occur, forming merocyanine in less than 2 picoseconds.
  • These findings indicate that the process is highly reversible and could lead to new ultrafast technologies using spiropyran-based materials.
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Water could be considered one of the essential natural resources on our planet. However, water contamination has become virtually ubiquitous during the past decades due to several factors, e.g.

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Rising concern about emerging and already persisting pollutants in water has urged the scientific community to develop novel remedial techniques. A new group of remediation methods is based on the modification of nanoscale zero-valent iron particles (nZVI), which are well known for treating volatile organic compounds and heavy metals. The properties of nZVI may be further enhanced by modifying their structure or surface using "green" polymers.

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The effect of the zeta potential of nano zero-valent iron (nZVI) and carbocatalyst on the activation of persulfate was investigated. The oxidation experiments were performed on three different compounds, with variously modified nZVI and three distinct carbocatalysts. From the obtained results, an evident linear correlation between nanoparticles' zeta potential and reaction rate constants of these three compounds oxidation may be observed.

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Environmental pollution causes irreversible damage to ecosystems and their structure. Therefore, the development of novel remedial techniques is a must for an effective response to emerging contaminants and those already persisting in the environment. The nanosized zero-valent iron (nZVI) is considered as an important nanostructure for the degradation of toxic compounds.

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Over the years, polyaniline (PANI) has received enormous attention due to its unique properties. Herein, it was chosen to develop a new polymeric composite material: reduced graphene oxide/polyaniline (rGO/PANI). The composite was prepared by a simple and cost-effective fabrication method of formation by mixing and sonication in various conditions.

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One of the most basic molecular photophysical processes is that of spin transitions and intersystem crossing between excited states surfaces. The change in spin states affects the spatial distribution of electron density through the spin orbit coupling interaction. The subsequent nuclear reorganization reports on the full extent of the spin induced change in electron distribution, which can be treated similarly to intramolecular charge transfer with effective reaction coordinates depicting the spin transition.

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This work describes an eco-friendly and sustainable technique for the synthesis of silver nanoparticles (nAg), where chitosan-poly(3-hydroxybutyrate) polymer conjugate (Chit-PHB) acts as a reducing and stabilizing material. The ensuing nanoparticles show an exceptional catalytic activity in the reduction of 4-nitrophenol to 4-aminophenol. nAg were characterized by several techniques, i.

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Raising health and environmental concerns over the nanoparticles synthesized from hazardous chemicals have urged researchers to focus on safer, environmentally friendlier and cheaper alternatives as well as prompted the development of green synthesis. Apart from many advantages, green synthesis is often not selective enough (among other issues) to create shape-specific nanoparticle structures. Herein, we have used a biopolymer conjugate and Pd and Pt precursors to prepare sustainable bimetallic nanoparticles with various morphology types.

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