Surface activity and colloidal properties of drugs and naturally occurring substances

1983 ◽  
pp. 124-228 ◽  
Author(s):  
D. Attwood ◽  
A. T. Florence
Science ◽  
1952 ◽  
Vol 116 (3024) ◽  
pp. 660-663 ◽  
Author(s):  
G. F. Dasher

2008 ◽  
Vol 327 (2) ◽  
pp. 446-450 ◽  
Author(s):  
N. Duerr-Auster ◽  
T. Eisele ◽  
R. Wepf ◽  
R. Gunde ◽  
E.J. Windhab

Author(s):  
Elena A. Lominoga ◽  
Konstantin S. Burmistrov ◽  
Victor S. Gevod

Mono- and di- esters of adipinic acid with long chain ethoxylated aliphatic alcohols (mixture of C10 – C12 and C16 – C18 alkohols) were obtained by the reaction of Synthanol DS-10 and adipinic acid and its dichloroanhydride. If adipinic acid with p-toluenesulfonic acid as catalyst were used as acylating agent and the mole ratio of Synthanol DS-10 to adipinic acid is 1:1 the yield of monoacylated product was 76 %. (temperature 120-125 °C, 3 h). If the mole ratio of Synthanol DS-10 to adipinic acid is 2:1 the yield of diacylated product was 80 % (temperature 120-125 °C, 6 h). Using dichloroanhydride of adipinic acid as acylating agent gives the 90 % (temperature 90-100 °C, 7.5 h) yield of diacylated product. The structure of all compounds was established by IR and NMR spectroscopy. Surface tension dependence on concentration in aqueous and alkaline medium was investigated for the obtained compounds. It was determined that the colloidal properties of the synthesized products differ significantly from the original Synthanol DS-10. The minimal surface tension of synthesized compounds is 25-33 mN/m. The surface activity of monoester in 5 % sodium hydroxide is 5.74 N·m2·mol-1 (for Synthanol DS-10 3.06 N·m2·mol-1). But in water their surface activity is 4.00 and 4.17, respectively. Opacity temperature in different mediums was established for the new compounds. Cloud point at the concentration of 0.25 g/dm3 of diester of adipinic acid in water (>100 °C) is significantly higher than for Synthanol DS-10 (81 °C) and for monoester (46 °C). In 5 % solution of sodium hydroxide the cloud points of all these compounds are the same (difference is 2-3 °C). The new products are stable in water and alkaline medium, but not stable in 0.1N solution of hydrochloric acid. The new synthesized surfactants from Synthanol DS-10 and adipinic acid (by the complex of colloidal and physical-chemical properties) are interesting as the ingredients of technical and household compositions. Forcitation:Lominoga E.A., Burmistrov K.S., Gevod V.S. Syntesis of dimeric surfactants based on synthanol DS-10 and adipinic acid. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N2. P. 91-96


Author(s):  
A. A. Livinskiy ◽  
M. E. Saitova ◽  
S. A. Livinskaya

The scientific and industrial community of specialists is developing indirect methods for predicting the technological properties of flour, which would reduce economic costs in a production environment. The results of comparing the colloidal properties of 4 samples of different producers of buckwheat flour from steamed cereals and 1 from green are presented. As methods for predicting the technological properties of flour used surface properties. The graphs of the dependence “surface tension at the air-liquid interface - concentration of dissolved substance” were constructed using experimental data obtained by the De Nui method. The surface activity of the compared samples was established by solving equations obtained by mathematical processing of experimental data. The adsorption properties of buckwheat flour samples were studied by the tensimetric method. Based on the study of surface properties, flour samples were arranged in a row according to the manifested colloidal properties. Studies of the surface properties of flour samples from steamed and non-steamed cereals showed that buckwheat flour produced by different enterprises is characterized by various adsorption properties, which should be taken into account during its storage and use in flour products. A sample of unpaired cereal has the highest surface activity, which allows us to recognize it as the best sample. The main influence on the technological advantages of flour is exerted by the fraction of flour with a particle size of up to 50 microns, the amount of which should be 58.69 ± 2%. At a higher content of particles of this fraction, the flour is characterized by reduced surface activity and has a higher hygroscopicity, which negatively affects its technological properties.


Author(s):  
A. W. Fetter ◽  
C. C. Capen

Atrophic rhinitis in swine is a disease of uncertain etiology in which infectious agents, hereditary predisposition, and metabolic disturbances have been reported to be of primary etiologic importance. It shares many similarities, both clinically and pathologically, with ozena in man. The disease is characterized by deformity and reduction in volume of the nasal turbinates. The fundamental cause for the localized lesion of bone in the nasal turbinates has not been established. Reduced osteogenesis, increased resorption related to inflammation of the nasal mucous membrane, and excessive resorption due to osteocytic osteolysis stimulated by hyperparathyroidism have been suggested as possible pathogenetic mechanisms.The objectives of this investigation were to evaluate ultrastructurally bone cells in the nasal turbinates of pigs with experimentally induced atrophic rhinitis, and to compare these findings to those in control pigs of the same age and pigs with the naturally occurring disease, in order to define the fundamental lesion responsible for the progressive reduction in volume of the osseous core.


Author(s):  
W. W. Barker ◽  
W. E. Rigsby ◽  
V. J. Hurst ◽  
W. J. Humphreys

Experimental clay mineral-organic molecule complexes long have been known and some of them have been extensively studied by X-ray diffraction methods. The organic molecules are adsorbed onto the surfaces of the clay minerals, or intercalated between the silicate layers. Natural organo-clays also are widely recognized but generally have not been well characterized. Widely used techniques for clay mineral identification involve treatment of the sample with H2 O2 or other oxidant to destroy any associated organics. This generally simplifies and intensifies the XRD pattern of the clay residue, but helps little with the characterization of the original organoclay. Adequate techniques for the direct observation of synthetic and naturally occurring organoclays are yet to be developed.


Author(s):  
G. M. Hutchins ◽  
J. S. Gardner

Cytokinins are plant hormones that play a large and incompletely understood role in the life-cycle of plants. The goal of this study was to determine what roles cytokinins play in the morphological development of wheat. To achieve any real success in altering the development and growth of wheat, the cytokinins must be applied directly to the apical meristem, or spike of the plant. It is in this region that the plant cells are actively undergoing mitosis. Kinetin and Zeatin were the two cytokinins chosen for this experiment. Kinetin is an artificial hormone that was originally extracted from old or heated DNA. Kinetin is easily made from the reaction of adenine and furfuryl alcohol. Zeatin is a naturally occurring hormone found in corn, wheat, and many other plants.Chinese Spring Wheat (Triticum aestivum L.) was used for this experiment. Prior to planting, the seeds were germinated in a moist environment for 72 hours.


Author(s):  
David R. Veblen

Extended defects and interfaces control many processes in rock-forming minerals, from chemical reactions to rock deformation. In many cases, it is not the average structure of a defect or interface that is most important, but rather the structure of defect terminations or offsets in an interface. One of the major thrusts of high-resolution electron microscopy in the earth sciences has been to identify the role of defect fine structures in reactions and to determine the structures of such features. This paper will review studies using HREM and image simulations to determine the structures of defects in silicate and oxide minerals and present several examples of the role of defects in mineral chemical reactions. In some cases, the geological occurrence can be used to constrain the diffusional properties of defects.The simplest reactions in minerals involve exsolution (precipitation) of one mineral from another with a similar crystal structure, and pyroxenes (single-chain silicates) provide a good example. Although conventional TEM studies have led to a basic understanding of this sort of phase separation in pyroxenes via spinodal decomposition or nucleation and growth, HREM has provided a much more detailed appreciation of the processes involved.


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