Wyniki wyszukiwania - BazTech

1

Światłoczułe barwniki organiczne o właściwościach luminescencyjnych – teoria i zastosowanie

Duda Alicja, Kopyciński Bartosz

Ochrona przed Korozją

|

2022

|

nr 1

12--19

PL

Zjawisko fotoluminescencji obejmuje fluorescencję i fosforescencję, które od blisko 180 lat stanowią przedmiot licznych badań i obserwacji naukowych. Jedną z grup związków chemicznych wykazujących zdolność do emisji kwantów światła na drodze wzbudzenia promieniowaniem elektromagnetycznym są barwniki organiczne. Posiadające unikalne właściwości fizykochemiczne, znajdują one zastosowanie w wielu dziedzinach nauki i przemysłu, takich jak elektronika, włókiennictwo czy branża medyczna. Niniejszy przegląd obejmuje opis fizycznych podstaw zjawisk fotoluminescencji wraz z omówieniem budowy i zastosowania wybranych grup organicznych substancji barwiących zaliczanych do fotoluminoforów.

EN

Photoluminescence phenomenon can be divided into fluorescence and phosphorescence which are a subject of research for almost 180 years now. Organic dyes are one of the groups of chemicals which can show the ability to emission of a light quanta as a result of excitation with electromagnetic radiation. Having unique physicochemical properties they can be applied in many industry branches such as electronics, textiles or medicinal technologies. This review focuses on a description of the physical foundations of the photoluminescence phenomenon as well as the structure and applications of selected organic compounds classified as photoluminophores.

2

Försterowski rezonansowy transfer energii (FRET) — podstawy fizyczne i zastosowania

Kotulska Agata M.

Postępy Fizyki

|

2021

|

T. 72, z. 1

8--15

PL

Försterowski rezonansowy transfer energii (FRET) jest jednym ze zjawisk fizycznych, które znalazły szerokie zastosowanie w biologii i przyczyniły się do zrozumienia funkcjonowania żywych komórek na poziomie molekularnym. Zmiany efektywności transferu energii wraz ze zmianą wzajemnej odległości donora i akceptora są widoczne podczas pomiarów spektroskopowych czasów życia luminescencji lub widma emisji. Zjawisko to umożliwia badanie wielu procesów takich jak hybrydyzacja DNA, zmiany konformacji białek czy też reakcji wiązania się przeciwciała z antygenem. Tradycyjnie do tego celu stosuje się barwniki organiczne lub białka fluorescencyjne. Jednak ze względu na ich wady, takie jak słabo rozdzielone, szerokie pasma absorpcyjne i emisyjne, krótkie — nanosekundowe czasy życia fluorescencji poziomów energetycznych czy fotowybielanie, nadal poszukuje się alternatywnych fluoroforów wykazujących pożądane cechy spektroskopowe. Rozwiązaniem dla napotykanych niepożądanych właściwości spektroskopowych barwników organicznych jest zastosowanie nanokryształów domieszkowanych jonami lantanowców jako donorów energii. Takie nanomateriały wykazują wysoką fotostabilność luminescencji, wąskie spektralnie pasma absorpcji i emisji, emisję antystokesowską oraz długie czasy zaniku luminescencji. W artykule przedstawiono podstawy fizyczne zjawiska FRET oraz zaprezentowano nowe wyzwania dla nanoluminoforów domieszkowanych jonami lantanowców, jako nowych alternatywnych donorów energii do studiowania procesów FRET.

EN

Förster Resonance Energy Transfer (FRET) is the physical phenomena that has found wide application in biology and contributed to understanding the functioning of living cells at the molecular level. Changes in the energy transfer eõciency are associated with the change of distance between the donor and acceptor, are visible during spectroscopic measurements, such as luminescence lifetimes or emission spectra. his phenomenon enables the study of many processes such as DNA hybridization, changes in protein conformation or the binding reaction of an antibody to an antigen. Traditionally, organic dyes or uorescent proteins are used for this purpose. However, due to their disadvantages, such as poorly separated, wide absorption and emission bands, short nanosecond luminescence lifetimes, and photobleaching, alternative uorophores with the desired spectroscopic characteristics are still being sought. he solution to the encountered imperfections of organic dyes is the use of nanocrystals doped with lanthanide ions as energy donors. his kind of nanomaterials show high luminescence photostability, narrow spectral absorption and emission bands, anti-Stokes emission and long luminescence decay times. his article presents the physical basis of the FRET phenomenon and new challenges for lanthanide-doped nanoluminophores as new alternative energy donors for researches in FRET processes.

3

Adsorpcja barwników organicznych na węglach aktywnych otrzymanych z porolniczych i poprodukcyjnych materiałów odpadowych

Kaźmierczak-Raźna J., Nowicki P., Franus W., Pietrzak R.

Przemysł Chemiczny

|

2016

|

T. 95, nr 7

1294--1299

PL

Przedstawiono wyniki badań nad otrzymywaniem węgli aktywnych za pomocą ogrzewania mikrofalowego oraz wykorzystaniem ich jako adsorbentów barwników organicznych z roztworów wodnych. Sorbenty otrzymywano przez aktywację bezpośrednią niskiej jakości siana oraz trocin drzew iglastych w piecu mikrofalowym o mocy 1400 W, przy częstotliwości 2,45 GHz. Zbadano wpływ rodzaju użytego prekursora na parametry teksturalne, właściwości kwasowo-zasadowe powierzchni oraz zdolności sorpcyjne otrzymanych materiałów. W celu porównania efektywności stosowanej metody badania obejmowały również wytworzenie węgli aktywnych z wykorzystaniem ogrzewania konwencjonalnego.

EN

Two activated C were produced by carbonization of low quality hay and sawdust from coniferous wood in a microwave oven under CO2 at 800°C, 1400 W, and 2.45 GHz studied for elementary compn., textural parameters and acidbase properties and then used for removal of methylene blue, methyl red and Kongo red dies from their aq. solns. (concns. 10–60 mg/L). The adsorption efficiency was described by Langmuir and Freundlich isotherms. The activated C produced by microwave heating were only in some cases more effective adsorbents than those produced under conventional heating.

4

Removal of Organic Dyes from Aqueous Solutions with Surfactant-Modified Magnetic Nanoparticles

Wybieralska K., Wajda A.

Polish Journal of Chemical Technology

|

2014

|

Vol. 16, nr 2

27--30

EN

The paper presents the results of studies on the possibility of using magnetic nanoparticles modified with selected hydrophobic surfactants for model post-production water purification. Colloidal solutions of iron hydroxide (III) and iron oxide (II and III) were obtained and their particles were subjected to surface modification using surfactants. Thus obtained magnetic fluids were used as active agents in the process of removing selected organic dyes from their aqueous solutions. The effectiveness of the modified compounds was analysed using spectrophotometric methods. It has been shown that the effectiveness of the process depends on the type of surfactant used to modify selected magnetic nanoparticles.

5

Photodegradation of organic dyes over nickel distributed CNT/TiO2 composite synthesized by a simple sol-gel method

Chen M. L., Oh W. C.

Materials Science Poland

|

2011

|

Vol. 29, No. 2

112--120

EN

In this study, the multi-walled carbon nanotubes were oxidized by m-chlorperbenzoic acid followed by the reaction with titanium n-butoxide and nickel nitrate to prepare Ni distributed CNT/TiO2 composite by a simple sol-gel method. The functional groups formed on the surface of MWCNTs were analyzed by Fourier transform infrared spectroscopy. The prepared Ni distributed CNT/TiO2 composite was characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and energy dispersive X-ray analysis. The photodegradation of methylene blue, methylene orange and rhodamine B solution under UV irradiation was employed to test the photocatalytic activity of the Ni distributed CNT/TiO2 composite. According to the results, Ni distributed CNT/TiO2 composite showed very excellent photocatalytic activity to decompose MB, MO and Rh.B solutions, due to the electron absorption effect of MWCNTs and electron trapping effect of nickel.

6

Influence of the decomposed substrates on the photocatalytic activity of the titanium dioxide modified by silver nanoparticles

Wodka D., Bielańska E., Socha R. P., Nowak P., Warszyński P.

Physicochemical Problems of Mineral Processing

|

2010

|

Vol. 45

99-112

EN

Photocatalytic activity of Ag/TiO2 composites obtained by photoreduction treatment (PRT) was investigated. The composite materials, containing 1.0 and 2.1 wt% of silver nanoparticles were obtained by depositing silver on the Evonic-Degussa P25 titania surface. Ag/TiO2 samples were examined by SEM, XPS and BET techniques. The XPS measurements revealed that silver particles were obtained mainly in metallic form. The photocatalytic activity of pure P25 and Ag/TiO2 composites was compared in photooxidation reaction of some model compound like: formic acid (FA), rhodamine B (RhB) and methylene blue (MB). Photodecomposition reaction was investigated in a batch reactor containing aqueous suspension of a photocatalyst illuminated by either UV or artificial sunlight (halogen lamp). The tests proved that small amount of silver nanoparticles deposited on titania surface triggers the increase in photocatalytic activity, this increase depends however on the type of substrate. The relation between the type of substrate and the activity of the composite was discussed.

7

Water purification using a novel reactor with the photoactive refill

Grzechulska-Damszel J., Morawski A. W.

Polish Journal of Chemical Technology

|

2009

|

Vol. 11, nr 1

61-63

EN

The aim of the presented work was the removal of organic dye, Acid Red 18, from water using a novel reactor with the photoactive refill. Titanium dioxide was immobilized on the base material as a thin layer from the alcoholic suspension followed by thermal stabilization. The prepared coating exhibits high stability in repeated cycles of water treatment. The complete removal of colour was achieved in a relatively short time of 14 hours. The proposed reactor with the photoactive refill solves the problem of the necessity of the replacement of the reactor or parts of the reactor when the photocatalysts activity decreases. In the case of activity drop of the photocatalyst, only the photoactivve refill can be easily replaced.

8

Removal of organic dye in the hybrid photocatalysis/membrane processes system

Grzechulska-Damszel J., Morawski A. W.

Polish Journal of Chemical Technology

|

2007

|

Vol. 9, nr 2

94-98

EN

The removal of azo dye Acid Red 18 in hybrid photocatalysis/membrane processes systems was investigated. The photocatalytic reactions were conducted in the reactor with photocatalyst suspended in the solution. The reaction solution was recirculated through the ultrafiltration system. A commercially available titanium dioxide (AeroxideŽ P25, Degussa, Germany) was used as a photocatalyst. The solution after the photocatalytic/UF reaction was applied as the feed for the membrane distillation process. The changes of various parameters, including the concentration of the dye, pH and the conductivity of the solution, TOC and TDS content were analyzed during the process. It was found that azo dye Acid Red 18 could be successfully decolourised in the hybrid photocatalysis/UF system. The catalyst particles were retained in the feed solution by means of the ultrafiltration membrane so the obtained permeate was free of TiO2. The application of ultrafiltration together with the photocatalytic process results in the separation of photocatalyst from the treated solution but does not give the complete removal of organic matter from the reaction mixture. Membrane distillation applied with the permeate after the photocatalysis/UF process as a feed gives a complete separation of TOC from the treated solution and the obtained product is practically pure water.

9

Spektroskopia pojedynczych fluoroforów

Molski A.

Wiadomości Chemiczne

|

2006

|

[Z] 60, 7-8

449-465

EN

This article is an introduction to single-fluorophore spectroscopy (SFS). The basic phenomenon seen in SFS is the fluctuations of fluorescence intensity of single nano-objects (dyes, biopolymers, nano-crystals, aggregates). These fluctuations are called fluorescence blinking and carry information on the dynamics of a fluorophore and its surroundings. In the simplest case the fluorescence trajectory jumps between two levels, a bright one (on) and a dark one (off). In this article on-off fluorescence blinking associated with triplet states of organic dyes, excitation of quantum dots, and enzymatic reactions at room temperatures are reviewed. The cited literature indicates current problems and may serve as an introduction to modelling and simulations of SFS.

10

Fizykochemiczne właściwości ekologicznych pigmentów nieorganicznych

Binkowski S., Krysztafkiewicz A., Jesionowski T., Żurawska J.

Chemia i Inżynieria Ekologiczna

|

2001

|

Vol. 8, nr 10

1025-1030

PL

Pigmenty nieorganiczne otrzymywano przez adsorpcję barwników organicznych, takich jak C.I. Direct Red 81 oraz C.I. Reactive Blue 19 na modyfikowanej powierzchni krzemionki strącanej. Powierzchnię krzemionki modyfikowano N-2-(aminoetylo)-3-aminopropylotrimetoksysilanem. Zastosowano różne ilości modyfikatora w celu określenia jego wpływu na proces adsorpcji. Zbadano właściwości fizykochemiczne i strukturalne modyfikowanych krzemionek oraz uzyskanych pigmentów.

EN

Inorganic pigments were obtained by attaching C.I. Direct Red 81 and C.I. Reactive Blue 19 dyes to modified silica surface. The silica surface was modified with N-2-(aminoethyl)-3-aminopropyltrimethoxysilane. Various amounts of modifiers were applied in order to determine their effect on the dye adsorption process. Physicochemical and structural properties of the modified silicas and of the obtained pigments were examined.