A series of microgel particles composed of a polystyrene (PS) core and a thermo-sensitive poly(N-isopropylacrylamide) (PNIPAM) shell with different shell thicknesses were investigated to elucidate the effect of microgel softness on its shear thickening behavior. Since the softness of the microgels increases with decreasing temperature through the volume phase transition effect of PNIPAM shell, the measured softness parameter, n, which is derived from the Zwanzig-Mountain equation, was used to measure and describe the combined influences of temperature and shell thickness. Confocal microscopy is used to investigate the interaction potential between microgel particles with different softness parameters. According to the obtained results, the softness parameter can provide an estimate for the shear thickening behavior of microgel suspensions, at least semi-quantitatively.
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http://dx.doi.org/10.1039/c4sm01181c | DOI Listing |
Polymers (Basel)
January 2025
Engineering Research Center of Oil and Gas Field Chemistry, Universities of Shaanxi Provence, Xi'an Shiyou University, Xi'an 710065, China.
In order to solve the problems of long dissolution and preparation time, cumbersome preparation, and easy moisture absorption and deterioration during storage or transportation, acrylamide (AM), acrylic acid (AA), sodium p-styrene sulfonate (SSS), and cetyl dimethylallyl ammonium chloride (DMAAC-16) were selected as raw materials, and the emulsion thickener P(AM/AA/SSS), which can be instantly dissolved in water and rapidly thickened, was prepared by the reversed-phase emulsion polymerization method. DMAAC-16, the influence of emulsifier dosage, oil-water ratio, monomer molar ratio, monomer dosage, aqueous pH, initiator dosage, reaction temperature, reaction time, and other factors on the experiment was explored by a single-factor experiment, and the optimal process was determined as follows: the oil-water volume ratio was 0.4, the emulsifier dosage was 7% of the oil phase mass, the initiator dosage was 0.
View Article and Find Full Text PDFDiagnostics (Basel)
January 2025
Odense Respiratory Research Unit (ODIN), Department of Clinical Research, Faculty of Health Sciences, University of Southern Denmark, 5000 Odense, Denmark.
: Ultrasound is a valuable diagnostic tool in the diagnostic work-up of dyspnea and can identify even small pleural effusions. The incorporation of shear wave elastography (SWE) represents a possible tool in stratifying pleural effusions by the risk of underlying malignancy. No previous studies on ultrasound with the incorporation of SWE have been conducted in an emergency department (ED), where such stratification might have a clinical impact by hastening referrals for the diagnostic work-up of underlying malignancy.
View Article and Find Full Text PDFJ Colloid Interface Sci
January 2025
School of Engineering, University of Liverpool, Liverpool, L69 3GH, United Kingdom.
Hypothesis: We hypothesise that superhydrophobic surfaces can achieve effective interfacial slip and drag reduction even under non-Newtonian, shear-thinning fluid flows. Unlike Newtonian fluids, where slip is primarily influenced by viscosity and surface tension, we anticipate that the shear-thinning nature of these fluids may enhance slip length and drag reduction.
Experiments And Numerical Analysis: The superhydrophobic surfaces used in this study, featuring a dual-scale random topography, were fabricated via a spray coating process, and low-concentration xanthan gum solutions (50-250 ppm) were used as model shear-thinning fluids of low elasticity.
J Neurosurg
January 2025
1Department of Bioengineering, George Mason University, Fairfax, Virginia.
Objective: The complex mix of factors, including hemodynamic forces and wall remodeling mechanisms, that drive intracranial aneurysm growth is unclear. This study focuses on the specific regions within aneurysm walls where growth occurs and their relationship to the prevalent hemodynamic conditions to reveal critical mechanisms leading to enlargement.
Methods: The authors examined hemodynamic models of 67 longitudinally followed aneurysms, identifying 88 growth regions.
Food Res Int
February 2025
College of Food Science, Chongqing Key Laboratory of Speciality Food Co-Built by Sichuan and Chongqing, Southwest University, Chongqing 400715 China. Electronic address:
Based on the huge blank of thickened fluid staple food for people with dysphagia, multiple in vitro simulations were utilized to develop the thickened fermented rice milk. Here, the effect of amylase content, hydrolysis time and thickener content were considered. The rheological study and Cambridge throat evaluation revealed that hydrolysis could significantly reduce the viscosity and yield stress of fermented rice milk, accompanied by the decreased swallowing residue.
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