A Study of the Colloidal System Carbon Dispersed in Xylene

1944 ◽  
Vol 48 (3) ◽  
pp. 125-133 ◽  
Author(s):  
V. R. Damerell ◽  
A. Urbanic
Keyword(s):  
Author(s):  
Robert J. Carroll ◽  
Marvin P. Thompson ◽  
Harold M. Farrell

Milk is an unusually stable colloidal system; the stability of this system is due primarily to the formation of micelles by the major milk proteins, the caseins. Numerous models for the structure of casein micelles have been proposed; these models have been formulated on the basis of in vitro studies. Synthetic casein micelles (i.e., those formed by mixing the purified αsl- and k-caseins with Ca2+ in appropriate ratios) are dissimilar to those from freshly-drawn milks in (i) size distribution, (ii) ratio of Ca/P, and (iii) solvation (g. water/g. protein). Evidently, in vivo organization of the caseins into the micellar form occurs in-a manner which is not identical to the in vitro mode of formation.


2010 ◽  
Vol 92 (4) ◽  
pp. 40007 ◽  
Author(s):  
K. Lichtner ◽  
S. H. L. Klapp
Keyword(s):  

RSC Advances ◽  
2012 ◽  
Vol 2 (29) ◽  
pp. 11111 ◽  
Author(s):  
V. Tudisca ◽  
M. A. Ricci ◽  
R. Angelini ◽  
B. Ruzicka

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jason J. Calvin ◽  
Tierni M. Kaufman ◽  
Adam B. Sedlak ◽  
Michelle F. Crook ◽  
A. Paul Alivisatos

AbstractPowder X-ray diffraction is one of the key techniques used to characterize the inorganic structure of colloidal nanocrystals. The comparatively low scattering factor of nuclei of the organic capping ligands and their propensity to be disordered has led investigators to typically consider them effectively invisible to this technique. In this report, we demonstrate that a commonly observed powder X-ray diffraction peak around $$q=1.4{\AA}^{-1}$$ q = 1.4 Å − 1 observed in many small, colloidal quantum dots can be assigned to well-ordered aliphatic ligands bound to and capping the nanocrystals. This conclusion differs from a variety of explanations ascribed by previous sources, the majority of which propose an excess of organic material. Additionally, we demonstrate that the observed ligand peak is a sensitive probe of ligand shell ordering. Changes as a function of ligand length, geometry, and temperature can all be readily observed by X-ray diffraction and manipulated to achieve desired outcomes for the final colloidal system.


Soft Matter ◽  
2017 ◽  
Vol 13 (37) ◽  
pp. 6439-6449 ◽  
Author(s):  
Umberto Capasso Palmiero ◽  
Azzurra Agostini ◽  
Enrico Lattuada ◽  
Simone Gatti ◽  
Jaspreet Singh ◽  
...  

A water-based colloidal system was designed, in which the particles can be buoyancy and optical matched with the solvent, and where inter-particle interactions are tuned by changing the temperature.


2008 ◽  
pp. 21-28
Author(s):  
Tatjana Kuljanin ◽  
Ljubinko Levic ◽  
Nevena Misljenovic ◽  
Gordana Koprivica

Electrokinetic potential is an important property of colloidal particles and, regarding the fact that it is a well defined and easily measurable property, it is considered to be a permanent characteristic of a particular colloidal system. In fact, it is a measure of electrokinetic charge that surrounds the colloidal particle in a solution and is in direct proportion with the mobility of particles in an electric field. Gouy-Chapman-Stern-Graham's model of electric double layer was adopted and it was proven experimentally that the addition of Cu++ ions to sugar beet pectin caused a reduction in the negative electrokinetic potential proportional to the increase of Cu++ concentration. Higher Cu++ concentrations increased the proportion of cation specific adsorption (Cu++ and H+) with regard to electrostatic Coulombic forces. Consequently, there is a shift in the shear plane between the fixed and diffuse layers directed towards the diffuse layer, i.e. towards its compression and decrease in the electrokinetic potential or even charge inversion of pectin macromolecules.


Author(s):  
Siti Hajar Musa ◽  
Norazlinaliza Salim ◽  
Norashikin Shamsudin ◽  
Mahiran Basri ◽  
Hamid Reza Fard Masoumi

Psoriasis is an autoimmune disease in which the symptoms are obviously appeared on the patient's body with thick, red/ salmon colour and dry patches. Clinically, topical treatment has been the first-line treatment for psoriasis, whether or not the systemic and phototherapy is required. Currently, cyclosporine is one of the standard oral medications used for moderate to a severe case of psoriasis. However, through oral delivery, it cannot be used for a long period and causes bad effects. Thus, a new delivery system of cyclosporine is in need to be developed to overcome its toxic effects by skipping the first pass body metabolism. A nanoemulsion colloidal system, as the main carrier for big, non-water-soluble cyclosporine, is believed could help in the delivery of activities through the stratum corneum of the skin layer. Nanoemulsion system, which mainly consists of oil phase (a mixture of virgin coconut oil, nutmeg oil, and cyclosporine), aqueous phase, and surfactant, was successfully being developed by using Mixture Experimental Design optimization tool with droplet size range between 110-160 nm. Stability studies were carried out with respect to; pH, storage at different temperatures, coalescence and Ostwald ripening mechanism, free-thaw cycle, and FTIR analysis. From the obtained results, this newly-developed nanoemulsion containing cyclosporine was proven to be stable and successfully maintained its physicochemical characteristics even after 3 months of storage at 4°C and 25°C temperature. Ostwald ripening mechanism contributed to the instability of the system at 45°C of storage. Introduction of standard cyclosporine, blank nanoemulsion, and nanoemulsion containing cyclosporine to the HaCaT cells in the treatment of MTT assay study has confirmed the safety of the nanoemulsion. Permeation study of the newly-developed nanoemulsion containing cyclosporine showed it was best fitted the Korsmeyer-Peppas kinetic model. In addition, the transepidermal water loss and hydration studies proved the efficacy of cyclosporine-loaded nanoemulsion in increasing the water storage of the volunteers’ normal skin after 3h of application.  


2016 ◽  
Vol 4 (2) ◽  
pp. 80
Author(s):  
Marwah Marwah ◽  
Citra Ayu Dewi ◽  
Ratna Azizah Mashami

The influence of cooperative learning type TAI based on chemoentrepreneurship to entrepreneurship motivation and conceptual understanding of students on colloidal system concept. Colloidal system concept was a concept that requires highly analysis with mastery of concepts that must be understood and require students practice in daily life. Learning will be more meaningful and provide a deep understanding of the learners when learning adapted to the characteristics of the subject matter. One effective solution was implement the cooperative learning type TAI based on chemoentrepreneurship. This study aimed to determine the influence of cooperative learning type TAI based on chemoentrepreneurship to entrepreneurship motivation and conceptual understanding of students. The study design used was pretest-posttest control group design, the sampling technique used cluster random sampling. The population in this study were all students of grade XII IPA SMA AL-Hamzar, Thatwas 50 students were divided into an experimental group of 26 students and a control group of 24 students. Entrepreneurship motivation analysis technique using multivariate test obtained scores of experimental group 63%, 74% and score of control group 66%, 68%. While conceptual understanding data using multivariate test with SPSS 16.0 for windows which scores obtained from initial test and final test on the conceptual understanding was no difference between the experimental group and control group that why used T test. Results obtained there was significant influences of cooperative learning type TAI based on chemoentrepreneurship to entrepreneurship motivation and it had no influence on students' conceptual understanding with sig = 0.304 > 0.05. So it can be concluded that there was no influence of cooperative learning type TAI based on chemoentrepreneurship to conceptual understanding of students.


2019 ◽  
Vol 62 (3) ◽  
pp. 201-207
Author(s):  
V. S. Gulyakov ◽  
A. S. Vusikhis ◽  
S. A. Petrova

Technogenic wastes are by-products of any production. At the same time, they can be a raw material for obtaining useful products. In particular, the waste from the Shabrovsky talcum combine, can be used to produce magnesian fluxes. They are dispersed, so must be agglomerated. Therefore, a method has been proposed for the preparation of non-roasting pellets. As a binder, a mixture of water and peat, treated in a hydropercussion cavitation device, was used. The resulting material is a colloidal system with particle size of less than 10–4 m. To measure the particle size, dynamic light scattering method was used. For comparison, a similar mixture of water and peat treated in a planetary mill was studied. An analysis of the data obtained has shown that particles of micron size occupy up to 90 % of volume in the sample after treatment of the mixture in hydropercussion cavitation device. In a sample that was ground in a planetary mill, most of the particles are characterized by tens or even hundreds of microns. Determination of crushing strength of non-roasting pellets is performed by compressing in a tensile machine of model P-0.5. For this purpose, the granules were used both immediately after granulation and after drying at 105 °C to a moisture content of less than 1.5 %. With an optimum proportion of binders of 15 – 20 %, the strength of raw pellets was 15 N, and the strength of dry pellets was 90 N. With a binder percentage of less than 15 %, both raw and dried pellets had low strength. With a binder content of more than 20 %, the mixture had excessive plasticity and tackiness, which led to the formation of conglomerates of several granules. Despite the fact that the strength parameters of the non-roasting pellet are lower than those of pellets used in blast-furnace production, they are sufficient for use in steelmaking processes.


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