scholarly journals Studies on the promoting effect of lipid-surfactant mixed micelles (MM) on intestinal absorption of colloidal particles. Dependence on particle size and administration site.

1987 ◽  
Vol 10 (6) ◽  
pp. 236-242 ◽  
Author(s):  
HIROSHI FUKUI ◽  
MASAHIRO MURAKAMI ◽  
HIROSHI YOSHIKAWA ◽  
KANJI TAKADA ◽  
SHOZO MURANISHI
Keyword(s):  
Particle Size ◽  
Intestinal Absorption ◽  
Colloidal Particles ◽  
Mixed Micelles ◽  
Promoting Effect

scholarly journals The Promotion/Inhibition of the Seepage Transport of Copper Ions by Suspension-Colloidal Particles with Wide Size Gradation

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Qingke Nie ◽  
Huawei Li ◽  
Haipeng Yang ◽  
Tengfei Ni ◽  
Sichen Jiang
Keyword(s):  
Heavy Metal ◽  
Particle Size ◽  
Large Scale ◽  
Colloidal Particles ◽  
Copper Ions ◽  
Small Scale ◽  
Average Particle ◽  
Promoting Effect ◽  
Transport Distance ◽  
Retarding Effect

Sand column tests were conducted to investigate the seepage transport of silicon powders (SPs) with two wide particle size ranges (30-2000 nm and 2-70 μm), including the cotransport of SPs and copper ions. The results show that the graded large-scale SP has an obvious inhibiting influence on the transport of copper ions. In contrast, in the presence of the graded small-scale SP, the concentration of copper ions in the effluent tends to increase; i.e., there appears to be a promoting effect. However, after a long transport distance, the presence of SPs, regardless of particle size, has an overall retarding effect on heavy metal pollutants (e.g., copper ions). The promoting effect of the increase in seepage velocity on the concentration of copper ions in the effluent is greater with the graded large-scale SPs than with the graded small-scale SPs. In terms of the microstructural characteristics by metallographic microscopy, the average particle size of the deposited graded small-scale SPs is almost constant at different transport distances, while that of the deposited graded large-scale SPs tend to decrease significantly with increasing transport distance; i.e., notable bed filtration is exhibited in the latter case. This physical mechanism also determines the sequence and rate of the retarding effect of SPs on heavy metal ions under seepage flow.

Stability of a Binary Colloidal Suspension and its effect on Colloidal Processing

1989 ◽  
Vol 155 ◽  
Author(s):  
Wan V. Shih ◽  
Wei-Heng Shih ◽  
Jun Liu ◽  
Ilhan A. Aksay
Keyword(s):  
Particle Size ◽  
Hard Sphere ◽  
Colloidal Particles ◽  
Colloidal Suspension ◽  
Fluid Phase ◽  
Ceramic Processing ◽  
Colloidal Processing ◽  
Interparticle Interactions ◽  
The Stability ◽  
Binary Suspension

The stability of a colloidal suspension plays an important role in colloidal processing of materials. The stability of the colloidal fluid phase is especially vital in achieving high green densities. By colloidal fluid phase, we refer to a phase in which colloidal particles are well separated and free to move about by Brownian motion, By controlling parameters such as pH, salt concentration, and surfactants, one can achieve high packing (green) densities in the repulsive regime where the suspension is well dispersed as a colloidal fluid, and low green densities in the attractive regime where the suspensions are flocculated [1,2]. While there is increasing interest in using bimodal suspensions to improve green densities, neither the stability of a binary suspension as a colloidal fluid nor the stability effects on the green densities have been studied in depth as yet. Traditionally, the effect of using bimodal-particle-size distribution has only been considered in terms of geometrical packing developed by Furnas and others [3,4]. This model is a simple packing concept and is used and useful for hard sphere-like repulsive interparticle interactions. With the advances in powder technology, smaller and smaller particles are available for ceramic processing. Thus, the traditional consideration of geometrial packing for the green densities of bimodal suspensions may not be enough. The interaction between particles must be taken into account.

scholarly journals Probing roto-translational diffusion of small anisotropic colloidal particles with a bright-field microscope

2021 ◽  
Vol 44 (4) ◽  
Author(s):  
Fabio Giavazzi ◽  
Antara Pal ◽  
Roberto Cerbino
Keyword(s):  
Particle Size ◽  
Rotational Motion ◽  
Colloidal Particles ◽  
Aqueous Suspension ◽  
Translational Motion ◽  
Translational Diffusion ◽  
Experimental Demonstration ◽  
Bright Field ◽  
Microscopic Scale ◽  
Bright Field Microscopy

Abstract Soft and biological materials are often composed of elementary constituents exhibiting an incessant roto-translational motion at the microscopic scale. Tracking this motion with a bright-field microscope becomes increasingly challenging when the particle size becomes smaller than the microscope resolution, a case which is frequently encountered. Here we demonstrate squared-gradient differential dynamic microscopy (SG-DDM) as a tool to successfully use bright-field microscopy to extract the roto-translational dynamics of small anisotropic colloidal particles, whose rotational motion cannot be tracked accurately in direct space. We provide analytical justification and experimental demonstration of the method by successful application to an aqueous suspension of peanut-shaped particles. Graphic abstract

High Uniformity of ZnO Nanoparticles Synthesized by Surfactant-Assisted Solvothermal Technique

2015 ◽  
Vol 1131 ◽  
pp. 43-48 ◽  
Author(s):  
Atthaphon Maneedaeng
Keyword(s):  
Particle Size ◽  
Zno Nanoparticles ◽  
Colloidal Particles ◽  
Hydrothermal Reaction ◽  
Solvothermal Reaction ◽  
Exciton Peak ◽  
Solvothermal Technique ◽  
Tauc Plot ◽  
High Uniformity ◽  
Surfactant Assisted

The aim of this study is to develop the synthetic procedure of Zinc Oxide (ZnO) nanoparticles by using surfactant-assisted solvothermal technique in order to produce highly uniform nanosize of ZnO particles. The solvothermal reaction evidently produces smaller ZnO particle sizes compared with those obtained from hydrothermal reaction. The zwitterionic surfactant is employed in this work and it typically works well under extremely conditions i.e. high pH levels, strong electrolytes, and high temperature. The key success of surfactant utilization in the solvothermal reaction is to create reversed micelles which act as nanoreactors or templates. Because micelle consist of polar cores that may occupy a finite amount of water forming a water pool for ZnO nanomaterial synthesis. Synthesized ZnO nanoparticles were obtained from solvothermal reaction at 180°C and 18 hours in a hydrothermal reactor. The ZnO colloidal particles were separated by paper filter and cellulose nitrate membrane, respectively. The XRD pattern shows that the structure of the synthesized ZnO nanoparticles is hexagonal wurtzite and the use of surfactant does not interfere the crystal growth and structure. The particle size distribution reveals a high uniform ZnO nanoparticles obtained via this method. The UV absorption spectrum of ZnO nanoparticles synthesized by this method presents exciton peak at approximate value of 365 nanometers. The energy band gap determined by Tauc plot is 3.31 eV. Moreover, TEM images confirm the particle size consistency showing the morphology of the prepared ZnO nanoparticles.

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