Aggregation of Methylene Blue in Frozen Aqueous Solutions Studied by Absorption Spectroscopy

HEGER, Dominik, Jaromír JIRKOVSKÝ a Petr KLÁN. Aggregation of Methylene Blue in Frozen Aqueous Solutions Studied by Absorption Spectroscopy. Journal of Physical Chemistry A. USA: The American Chemical Society, 2005, roč. 109, č. 30, s. 6702-6709. ISSN 1089-5639.

Základní údaje

• Originální název: Aggregation of Methylene Blue in Frozen Aqueous Solutions Studied by Absorption Spectroscopy
• Název česky: Aggregation of Methylene Blue in Frozen Aqueous Solutions Studied by Absorption Spectroscopy
• Autoři: HEGER, Dominik (203 Česká republika), Jaromír JIRKOVSKÝ (203 Česká republika) a Petr KLÁN (203 Česká republika, garant).
• Vydání: Journal of Physical Chemistry A, USA, The American Chemical Society, 2005, 1089-5639.

Další údaje

• Originální jazyk: angličtina
• Typ výsledku: Článek v odborném periodiku
• Obor: 10403 Physical chemistry
• Stát vydavatele: Spojené státy
• Utajení: není předmětem státního či obchodního tajemství
• Impakt faktor: Impact factor: 2.898
• Kód RIV: RIV/00216224:14310/05:00012597
• Organizační jednotka: Přírodovědecká fakulta
• UT WoS: 000230897000012
• Klíčová slova anglicky: photochemistry; aggregation; methylene blue
• Štítky: aggregation, methylene blue, Photochemistry
• Příznaky: Mezinárodní význam

Anotace

The paper presents a qualitative as well as quantitative spectroscopic study of methylene blue (MB) aggregation that occurs upon freezing the aqueous solutions over a wide concentration range. The Gaussian curve analysis and the multivariate curve resolution-alternating least squares method were used to determine the number and concentration of chemical species responsible for the overlaying absorption visible spectra measured. The results show the extent of aggregation for the concentrations above 10(-7) mol L(-1), being dependent on the freezing rate and the initial concentration. While the local concentration of MB at the grain boundaries of polycrystalline ice increased by approximately 3 orders of magnitude upon fast freezing at 77 K compared to the liquid phase, the concentration raised at least by 6 orders of magnitude upon slow freezing at 243 K. Since enhancement of the local concentration of solutes plays an important role in (photo)chemical transformations in solid aqueous media, this work helps to understand how the initial conditions control the course of the process. The results are relevant in other interdisciplinary fields, such as environmental chemistry, cosmochemistry, or geochemistry.

Anotace česky

The paper presents a qualitative as well as quantitative spectroscopic study of methylene blue (MB) aggregation that occurs upon freezing the aqueous solutions over a wide concentration range. The Gaussian curve analysis and the multivariate curve resolution-alternating least squares method were used to determine the number and concentration of chemical species responsible for the overlaying absorption visible spectra measured. The results show the extent of aggregation for the concentrations above 10(-7) mol L(-1), being dependent on the freezing rate and the initial concentration. While the local concentration of MB at the grain boundaries of polycrystalline ice increased by approximately 3 orders of magnitude upon fast freezing at 77 K compared to the liquid phase, the concentration raised at least by 6 orders of magnitude upon slow freezing at 243 K. Since enhancement of the local concentration of solutes plays an important role in (photo)chemical transformations in solid aqueous media, this work helps to understand how the initial conditions control the course of the process. The results are relevant in other interdisciplinary fields, such as environmental chemistry, cosmochemistry, or geochemistry.

Návaznosti

• GA205/05/0819, projekt VaV: Název: Environmentální důsledky fotochemických transformací v ledu a sněhu

Investor: Grantová agentura ČR, Environmentální důsledky fotochemických transformací v ledu a sněhu

• MSM0021622412, záměr: Název: Interakce mezi chemickými látkami, prostředím a biologickými systémy a jejich důsledky na globální, regionální a lokální úrovni (INCHEMBIOL) (Akronym: INCHEMBIOL)

Investor: Ministerstvo školství, mládeže a tělovýchovy ČR, Interakce mezi chemickými látkami, prostředím a biologickými systémy a jejich důsledky na globální , regionální a lokální úrovni