scholarly journals Influence of particle size on the thermoresponsive and rheological properties of aqueous poly(N-isopropylacrylamide) colloidal suspensions

2020 ◽  
Vol 43 (1) ◽  
Author(s):  
Chandeshwar Misra ◽  
Sanjay Kumar Behera ◽  
Ranjini Bandyopadhyay
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Dianbin Su ◽  
Xin-Di Zhu ◽  
Yong Wang ◽  
Dong Li ◽  
Li-Jun Wang

Abstract Citrus fiber dispersion with different concentrations (5–25 g/kg) was treated by high-pressure homogenization (90 and 160 MPa) for two cycles. The particle size distribution, hydration properties of powders, morphology and rheological measurements were carried out to study the microstructure and rheological properties changes by high-pressure homogenization (HPH). In conclusion, the HPH can reduce the particle size of fiber, improve the water holding capacity and water binding capacity. Furthermore, fiber shape can be modified from globular cluster to flake-like slices, and tiny pores can be formed on the surface of citrus fiber. The apparent viscosity, storage modulus and loss modulus were increased by HPH whereas the activation energy was reduced. The Hershcel–Bulkley model, Carreau model and Power Law mode were selected to evaluate the rheological properties.


2021 ◽  
Vol 29 (9_suppl) ◽  
pp. S1361-S1370
Author(s):  
Xuwu Luo ◽  
Guancheng Jiang ◽  
Xinliang Li ◽  
Lili Yang

In this paper, sodium montmorillonite was modified with gelatin of different concentrations, and various colloidal characteristics of the gelatin-treated clays were measured and analyzed in detail. First, the influence of gelatin on the interlayer space of Mt layers was investigated by X-ray diffraction analysis. Moreover, the aggregation of Mt particles was examined using a combination of electron microscopy and particle size distribution experiments, while the variation of the electrical property of Mt was measured using ζ potential test. Gelatin of different concentrations can increase the particle size of Mt in different degrees. The addition of 4% gelatin could improve the ζ potential of Mt from −30.65 to −15.55 mV. The wettability change of modified Mt induced by the adsorption of gelatin was followed by measurements of water contact angle and observations of the morphology of Mt/gelatin membrane through SEM images. 4% gelatin could improve the water contact angle of Mt to 81.3°. Finally, the rheological properties of Mt/gelatin dispersion including shear viscosity and shear stress were measured using a stress-controlled rheometer. All of the results were consistent by showing that the overall colloidal characteristics and behavior of the gelatin-treated Mt strongly varied depending on the gelatin concentration used in the modification process. These results can provide a deep and comprehensive understanding of the colloidal properties of clay/gelatin systems and give important guidance for the performance design and improvement of Mt/gelatin composite materials. Furthermore, this study can also be expanded the application of gelatin and its composites to other fields.


2020 ◽  
Vol 11 (11) ◽  
pp. 9547-9559
Author(s):  
Annika Feichtinger ◽  
Elke Scholten ◽  
Guido Sala

Particle size distribution and particle size ratio have an important effect on rheological properties of model chocolate samples, but also other factors like particle shape, surface roughness and hydrophilicity should be taken into account.


2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Bingwen Wang ◽  
Tingyong Xiong ◽  
Lijing Gao ◽  
Yuepeng Chai ◽  
Xiangyu Cui ◽  
...  

The key technology in filling mining is the gravity transportation of high-density slurries, and the filling system design is a significant part of this technology. The filling effect depends on the fluidity of the filling slurry. To investigate the influence of the gradation of tailings on the rheological properties of the filling slurry, this study uses particle size analysis to prepare three types of tailings: powder-, relatively fine-, and fine-grained tailings, which are then mixed in different proportions. The rheological properties of the resulting filling slurries are tested; the viscosity coefficients and yield stresses of the slurries are obtained using the analysis software provided with the MCR102 advanced rheometer that is used to measure the rheological properties of the slurries. The experimental results demonstrate that there is no absolute relationship between the rheological properties of the slurry and the size of the tailings particles, but the rheological properties are related to the gradation of tailings. Lubricating effect is weakened with an insufficient content of powder-grained particles in the tailings. On the contrary, when the content of powder-grained particles in the tailings is too high, the viscous substances in the slurry increase. Both of these conditions can increase the friction loss of the slurry.


Molecules ◽  
2020 ◽  
Vol 25 (4) ◽  
pp. 860 ◽  
Author(s):  
Helen Coarita Fernandez ◽  
Diana Amaya Ramirez ◽  
Ruben Teixeira Franco ◽  
Pierre Buffière ◽  
Rémy Bayard

Different methods were tested to evaluate the performance of a pretreatment before anaerobic digestion. Besides conventional biochemical parameters, such as the biochemical methane potential (BMP), the methane production rate, or the extent of solubilization of organic compounds, methods for physical characterization were also developed in the present work. Criteria, such as the particle size distribution, the water retention capacity, and the rheological properties, were thus measured. These methods were tested on samples taken in two full-scale digesters operating with cattle manure as a substrate and using hammer mills. The comparison of samples taken before and after the pretreatment unit showed no significant improvement in the methane potential. However, the methane production rate increased by 15% and 26% for the two hammer mills, respectively. A relevant improvement of the rheological properties was also observed. This feature is likely correlated with the average reduction in particle size during the pretreatment operation, but these results needs confirmation in a wider range of systems.


2012 ◽  
Vol 509 ◽  
pp. 155-161 ◽  
Author(s):  
Ji Zhe Zhang ◽  
Martin Van de Ven ◽  
Shao Peng Wu

This paper investigated the influence of nanoclay on the properties of polymer modified bitumen(PMB). The nanoclay-polymer modified bitumen has been produced by mixing a standard 70/100 pen bitumen with polymer at a fixed proportion and then mixed with different amount of nanoclay. The rheological behaviour of the samples have been determined using dynamic shear rheometer. The morphology of the samples as well as the distribution of polymer and nanoclay throughout the bitumen have been characterized with a fluorescence microscopy. The result indicate that the rheological properties of nanoclay-polymer modified bitumens dependent on the percentage nanoclay. The morphology result shows that dispersed polymer particles existed in continuous bitumen phase and the addition of nanoclay does not seem to change the particle size of the polymer.


2006 ◽  
Vol 05 (02n03) ◽  
pp. 259-264 ◽  
Author(s):  
MEI LI ◽  
QINGHUA LU ◽  
ZONGGUANG WANG

Tin oxide nanoparticles with a narrow size distribution were prepared by pulsed laser ablation of a pure tin target both in aqueous solutions and in pure water. Laser beam of 266 nm, 355 nm and 532 nm from an Nd :YAG laser were applied and the wavelength effects on preparation of tin oxide particles were examined. The particle size and phase structure were characterized by using transmission electron microscope (TEM). The observation revealed that the particle size of the nanoparticles was about 2–5 nm. Chemical components of obtained nanoparticles were analyzed by using an energy dispersive X-ray analysis (EDX) and the results demonstrated that the nanoparticles mainly consisted of Sn and O elements. Furthermore, aqueous solutions of sodium dodecyl sulfate (SDS) were used to study the influence of surfactant concentration on the formation of tin oxide nanoparticles. When the surfactant reached critical micelle concentration, relatively stable colloidal suspensions consisting of well-dispersed tin oxide nanoparticles were obtained. UV-vis spectrometer was used to measure the absorption of suspensions of tin oxide nanoparticles.


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