Contractive Force and Transformation of Microfibril with Aqueous Sodium Hydroxide Solution for Wood

Holzforschung ◽  
2000 ◽  
Vol 54 (3) ◽  
pp. 315-320 ◽  
Author(s):  
Takato Nakano ◽  
Junji Sugiyama ◽  
Misato Norimoto
Keyword(s):  
Sodium Hydroxide Solution ◽  
Heating Temperature ◽  
Alkali Treatment ◽  
Twist Angle ◽  
Aqueous Sodium Hydroxide ◽  
Picea Jezoensis ◽  
Longitudinal Contraction ◽  
Aqueous Sodium Hydroxide Solution ◽  
Naoh Solution ◽  
Tangential Directions

Summary The mechanism of longitudinal contraction of Yezo spruce (Picea jezoensis Carr.) during treatment with aqueous NaOH solution is discussed. The contraction of wood samples increased with an increase in the concentration of NaOH solution and in heating temperature. Measurements of the stress relaxation and the twist angle during the alkali treatment showed that the alkali treatment caused the contractive and twist forces of a tracheid cell wall in longitudinal and tangential directions, depending on the components of contractive force. The temperature dependence of the contraction and the thermodynamics led to the conclusion that the longitudinal contraction of samples is due to that of microfibrils via an entropy-elastic force.

Instant Microwave Synthesis of Titania Nanoflowers for Application in DSSCs

2015 ◽  
Vol 1119 ◽  
pp. 14-18
Author(s):  
Sofia Javed ◽  
Muhammad Aftab Akram ◽  
Mohammad Mujahid
Keyword(s):  
Titanium Dioxide ◽  
Hydrofluoric Acid ◽  
Sodium Hydroxide Solution ◽  
Dye Sensitized Solar Cells ◽  
Aqueous Sodium Hydroxide ◽  
Environment Friendly ◽  
Aqueous Sodium Hydroxide Solution ◽  
Dye Sensitized ◽  
Aqueous Conditions ◽  
Sensitized Solar Cells

Nanoflowers are desirable in light driven applications like Dye Sensitized Solar Cells (DSSCs) due to their large surface area and greater light absorption capabilities. An instant, simple, cheap and environment friendly method of preparing titanium dioxide nanoflowers is presented. The nanoflowers are produced in a time as short as 5 minutes in aqueous conditions without the use of hazardous hydrofluoric acid or organic surfactants at 1 atm. pressure and low temperature of 100°C. Titanium dioxide commercial nanopowders are treated with microwaves in an aqueous sodium hydroxide solution for small durations. The resulting powders are annealed at 450°C in air and characterization is performed using XRD, SEM and Raman spectroscopy.

Cleavage Reactions of 5-Arylazo Derivatives of 1-Methyl-2-benzyl-2-imidazolin-4-ones

1975 ◽  
Vol 30 (7-8) ◽  
pp. 603-605 ◽  
Author(s):  
Nazmi Abdel Latif Kassab ◽  
Abdel Hamid Harhash ◽  
Sanna Osman Abd Allah
Keyword(s):  
Sodium Hydroxide Solution ◽  
Aqueous Sodium Hydroxide ◽  
The Other ◽  
Ring Cleavage ◽  
Prolonged Heating ◽  
Aqueous Sodium Hydroxide Solution ◽  
Aqueous Sodium ◽  
Triazine Derivatives ◽  
Cleavage Reactions ◽  
Derivatives Of

The 5-arylazo-1-methyl-2-benzyl-2-imidazolin-4-ones (1 a-c) undergo ring cleavage with 1% aqueous sodium hydroxide solution affording α-arylhydrazono-phenacetyl-sarcosine amide (2). Prolonged heating of 1 and 2 with the same reagent yields the cyanamide (3). On the other hand, when 1 a-c were refluxed with acetic acid the triazinones (4) were obtained. The latter adds one mole of Grignards reagent to yield the 5-hydroxy-1,2,4-triazine derivatives (5).

Equilibrium and Kinetics of the Extraction of Gallium(III) from Sodium Hydroxide Solutions with 7-Dodecenyl-8-quinolinol (Kelex 100)

1993 ◽  
Vol 58 (5) ◽  
pp. 1093-1102 ◽  
Author(s):  
Aleksandra A. Mitrovic ◽  
Slobodan K. Milonjic ◽  
Zoja E. Ilic ◽  
Radomir V. Stevanovic
Keyword(s):  
Sodium Hydroxide ◽  
Sodium Hydroxide Solution ◽  
Aqueous Sodium Hydroxide ◽  
Sodium Concentration ◽  
Extraction Kinetics ◽  
Aqueous Sodium Hydroxide Solution ◽  
Ph Values ◽  
Constant Ph ◽  
Equilibrium And Kinetics ◽  
Kinetics Of

The influence of hydroxide ions concentration of the aqueous sodium hydroxide solution, at constant sodium concentrations, on the gallium extraction with Kelex 100 was examined in the hydroxide concentration range from 0.02 to 0.5 mol dm-3. The percentage of extracted gallium increases from 51% to 98% within the investigated hydroxide concentration range. The influence of sodium concentrations (from 1 to 6 mol dm-3) on the gallium extraction was also studied at constant pH values. The decrease of extracted gallium is slight for the sodium concentration up to 3 mol dm-3, while for the higher ones it is pronounced. The extraction kinetics was studied using a mixer-type apparatus. The rate expression of the extraction reaction of gallium with Kellex 100, for both lower and higher hydroxide concentrations are ascertained.

scholarly journals A new protocol for the synthesis of 4,7,12,15-tetrachloro[2.2]paracyclophane

2016 ◽  
Vol 12 ◽  
pp. 2443-2449 ◽  
Author(s):  
Donghui Pan ◽  
Yanbin Wang ◽  
Guomin Xiao
Keyword(s):  
Organic Solvent ◽  
Sodium Hydroxide ◽  
Anion Exchange ◽  
Organic Waste ◽  
Silver Oxide ◽  
Sodium Hydroxide Solution ◽  
Aqueous Sodium Hydroxide ◽  
Product Yield ◽  
Aqueous Sodium Hydroxide Solution ◽  
Aqueous Sodium

We report a green and convenient protocol to prepare 4,7,12,15-tetrachloro[2.2]paracyclophane, the precursor of parylene D, from 2,5-dichloro-p-xylene. In the first bromination step, with H2O2–HBr as a bromide source, this procedure becomes organic-waste-free and organic-solvent-free and can appropriately replace the existing bromination methods. The Winberg elimination–dimerization step, using aqueous sodium hydroxide solution instead of silver oxide for anion exchange, results in a significant improvement in product yield. Furthermore, four substituted [2.2]paracyclophanes were also prepared in this convenient way.

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