WILBERT

Wildauer Bücher+E-Medien Recherche-Tool

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Colloid & polymer science 267 (1989), S. 915-922 
    ISSN: 1435-1536
    Keywords: Carboxymethylcellulose ; cellulosederivatives ; equilibriumsorption ; cationicdye ; Langmuir-isotherm ; cooperativesorption ; structure ofboundwater
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Cellulose fabric samples were carboxymethylated for different duration. The degree of substitution was changing through a maximum value during the reaction time. The equilibrium sorption of a cationic dye by cellulosic fibers of different degrees of carboxymethylation was investigated in buffered and in unbuffered systems. The sorption isotherms were interpreted by two kinds of approximations based upon Langmuir isotherm. From the sorption data extrapolated to zero dye concentration affinities were calculated. The temperature dependence of affinities gave the values of heat and entropy of dyeing which were changing along the reaction time similarly to the degree of substitution.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Colloid & polymer science 266 (1988), S. 716-720 
    ISSN: 1435-1536
    Keywords: Carboxymethylation ; cellulose ; cellulose derivatives ; design of experiment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Cellulosic fabric composed of 84 % cotton and 16 % viscose rayon fiber was carboxymethylated. The influence of the reaction parameters (concentration of the reagents, time of reaction) on the degree of substitution was studied in the process, applying sodium hydroxide and monochloroacetic acid in one bath. Two kinds of regression equations were used to calculate approximately the degree of substitution. These polynomials can be used for the selection of reaction parameters to obtain a sample of a given degree of substitution.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Colloid & polymer science 268 (1990), S. 649-657 
    ISSN: 1435-1536
    Keywords: Carboxymethylcellulose ; cellulose derivatives ; acidhydrolysis ofcellulose ; accessibility ofcellulose
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Cotton cellulose was swollen in a sodium hydroxide solution and carboxymethylated by a two-bath method for different periods of time for each process. The kinetics of acid hydrolysis and the crystallinity of the swollen and carboxymethylated samples were measured. The proportion of broken bonds, rate constants for hydrolysis, and permeability of cellulose to hydrolyzing agents were calculated. The susceptibility of glycosidic linkages to acid hydrolysis was improved by carboxymethylation more than by swelling in alkali. The increased accessibility of carboxymethylcellulose to acid was regarded as a consequence of increased intra-and intercrystalline swelling and of the glycosidic bonds' weakness caused by the electron-attracting carboxymethyl group on the C-6 position.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Colloid & polymer science 263 (1985), S. 842-846 
    ISSN: 1435-1536
    Keywords: Equilibrium sorption ; carboxymethyl cellulose ; cooperative sorption ; dual sorption ; cationic dye
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The equilibrium sorption of a cationic dye, C.I.Basic Red 18, by a partially carboxymethylated cellulose membrane at pH 4.2 was investigated. The sorption isotherm was interpreted by considering a cooperative mode of binding of the dye by the polymer. The intrinsic binding constantK, the number of consecutive polymer residues occupied by a single dye moleculen, and the cooperativity parameterΩ were determined. In the case of the polymer with high content of carboxylate groups an additional mode of dye binding was presumed.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Colloid & polymer science 267 (1989), S. 349-352 
    ISSN: 1435-1536
    Keywords: Carboxymethylcellulose ; cellulosederivatives ; iodinesorption ; accessibility ; porosity ; wettability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Cellulosic fabric was carboxymethylated by single-bath method for different durations. $$\overline {DS} $$ arrived at a maximum when plotted against the time of reaction. This might be interpreted by the dissolution of the highly substituted fractions. The fibrous character of the carboxymethylated samples $$(\overline {DS} = 0.045 - 0.075)$$ remained unchanged, but the accessibility of the cellulose characterized by iodine sorption, porosity, and wettability changed significantly. The carboxymethylation had a complex effect on the investigated parameters: the values of accessibility were increasing initially, caused by opening the fibrillar structure, but decreasing later as the swollen structure was collapsing during air-drying. The studied properties were depending not only on the changes in $$\overline {DS} $$ but also on the reaction parameters.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 112 (1982), S. 10-18 
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Intermediate subviral particles (ISVP) derived from reovirus represent a simple model system for the switch-on of transcriptase function. In such particles the endogenous transcriptase is present in a switched-off form, one step removed from the switched-on state. Switch-on of transcriptase function is an active process in this system and can be triggered by K+ ions. A variety of agents which affect gene expression in cells were tested for an effect on switch-on in ISVP. Marked effects on switch-on in ISVP were observed with a diverse group of test agents, including DMSO and other solvents, BUdR, TdR, caffeine, theophylline, and temperature. The correlation in response between ISVP and cells suggests that the ISVP system may be useful as a model for studying the biochemical mechanisms underlying the perturbative effects of such agents on gene expression in cells.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 237 (1972), S. 402-403 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Sensitization studies were performed with asychronous Chinese hamster cells using cell culturing techniques and irradiation procedures as described previously4. Fig. 1 shows the effect of 500 µM 5-nitro-2-furaldehyde-semicarbazone (nitrofurazone, Norwich Pharmacal, Norwich, New York) on the ...
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Food Chemistry 38 (1990), S. 97-103 
    ISSN: 0308-8146
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    ISSN: 0304-4165
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology , Chemistry and Pharmacology , Medicine , Physics
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    ISSN: 0304-4165
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology , Chemistry and Pharmacology , Medicine , Physics
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...