Polycations and Their Complexes

Free-energy changes have been determined for the binding of the anionic dyes Orange II and Methyl Orange to diethylaminoethyl cellulose and triethylaminoethyl cellulose. These polycations resemble wool and other natural polycations in some respects. It is shown, however, that the Gilbert-Rideal theory is not satisfactory for cellulosic polycations, and alternative treatments are given. It was found that the order of binding of some simple anions was I- > Br- > Cl-. The sulphate ion behaved anomalously and appeared to be sensitive to changes in the intersite distance. Diffuse reflectance spectra showed evidence of a metachromatic color change in the spectrum of the bound dyes.

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Artificial weathering of tropical woods. Part 2: Color change

Holzforschung ◽

10.1515/hf.2004.085 ◽

2004 ◽

Vol 58 (5) ◽

pp. 558-565 ◽

Cited By ~ 24

Author(s):

Masanori Kishino ◽

Takato Nakano

Keyword(s):

Diffuse Reflectance ◽

Color Change ◽

Reflectance Spectra ◽

Acacia Auriculiformis ◽

Eucalyptus Marginata ◽

Artificial Weathering ◽

Diffuse Reflectance Spectra ◽

Before And After ◽

The Difference ◽

Tropical Woods

Abstract This paper describes the change in diffuse reflectance Fourier transform infrared (DRIFT) and ultraviolet-visible (UV-Vis) diffuse reflectance spectra of the following eight tropical woods during artificial weathering up to 600 h in relation to their color changes, especially to yellowing: Amnurana acreana, Acacia auriculiformis, Dipterocarpus spp., Eucalyptus marginata, Eucalyptus robusta, Shorea spp. and Tabebuia spp. with relatively high and low specific gravity. For A. acreana, A. auriculiformis, Dipterocarpus spp. and both Tabebuia spp., Δb* (yellowing) increased with exposure up to 50 h, and decreased above 50 h. For E. marginata, E. robusta and Shorea spp., on the other hand, both Δa* (shift to red) and Δb* decreased with increased exposure time. For woods in which Δb* increased, the Δb* showed a positive dependence on the difference in relative intensity ratio of a band at 1740 cm–1 to that at 2900 cm–1 (ΔD1740/D2900) in DRIFT spectra of specimens before and after exposure. This result indicated that the increased band at 1740 cm–1 played a significant role in the increased Δb*. Then again, also for woods in which Δb* decreased, the ΔD1740/D2900 increased, but was not related to the Db*. The ΔD1740/D2900 for woods in which Δb* decreased had a positive relationship to the difference in remission function at 410 nm (ΔF(R∞)410) in UV-Vis diffuse reflectance spectra for specimens before and after exposure, while woods in which Δb* increased were independent of the ΔF(R∞)410. Therefore, it is suggested that woods in which Δb* increased and decreased differ from one another in the contribution to the increase in the band at 1740 cm–1, resulting in either an increase or decrease of Δb*.

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Effect of differently sized nanoparticles’ accumulation on the optical properties ofex vivonormal and adenomatous human colon tissue with OCT imaging and diffuse reflectance spectra

Laser Physics Letters ◽

10.1088/1612-2011/11/8/085901 ◽

2014 ◽

Vol 11 (8) ◽

pp. 085901 ◽

Cited By ~ 2

Author(s):

Y Q Zhang ◽

G Y Wu ◽

H J Wei ◽

Z Y Guo ◽

H Q Yang ◽

...

Keyword(s):

Optical Properties ◽

Diffuse Reflectance ◽

Human Colon ◽

Reflectance Spectra ◽

Colon Tissue ◽

Diffuse Reflectance Spectra ◽

Oct Imaging

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Studies on the structures of cobalt pyridinaldoximates. I. The preparation and structural investigation of those complexes containing chlorine

Australian Journal of Chemistry ◽

10.1071/ch9670429 ◽

1967 ◽

Vol 20 (3) ◽

pp. 429 ◽

Cited By ~ 6

Author(s):

MW Blackmore ◽

RJ Magee

Keyword(s):

Diffuse Reflectance ◽

Structural Investigation ◽

Reflectance Spectra ◽

Diffuse Reflectance Spectra

The preparation of some new complexes of cobalt and 2-pyridinaldoxime are described. Magnetic and conductometric measurements are reported along with their infrared, ultraviolet and visible, and diffuse reflectance spectra. The possible structure of one of the complexes is postulated.

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