Probing the Morphology and Nanoscale Mechanics of Single Poly(N-isopropylacrylamide) Microgels Across the Lower-Critical-Solution Temperature by Atomic Force Microscopy

Small ◽  
2008 ◽  
Vol 4 (1) ◽  
pp. 119-126 ◽  
Author(s):  
Oya Tagit ◽  
Nikodem Tomczak ◽  
G. Julius Vancso
Keyword(s):  
Atomic Force Microscopy ◽  
Lower Critical Solution Temperature ◽  
Solution Temperature ◽  
Critical Solution Temperature ◽  
Nanoscale Mechanics ◽  
Force Microscopy ◽  
Atomic Force

Nanoscale mechanics of brain abscess: An atomic force microscopy study

Micron ◽  
2018 ◽  
Vol 113 ◽  
pp. 34-40 ◽  
Author(s):  
Eleonora Minelli ◽  
Tanya Enny Sassun ◽  
Massimiliano Papi ◽  
Valentina Palmieri ◽  
Francesca Palermo ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Brain Abscess ◽  
Microscopy Study ◽  
Atomic Force Microscopy Study ◽  
Nanoscale Mechanics ◽  
Force Microscopy ◽  
Atomic Force

Nanoscale mechanics by tomographic contact resonance atomic force microscopy

Nanoscale ◽  
2014 ◽  
Vol 6 (2) ◽  
pp. 962-969 ◽  
Author(s):  
Gheorghe Stan ◽  
Santiago D. Solares ◽  
Bede Pittenger ◽  
Natalia Erina ◽  
Chanmin Su
Keyword(s):  
Atomic Force Microscopy ◽  
Nanoscale Mechanics ◽  
Force Microscopy ◽  
Atomic Force ◽  
Contact Resonance

scholarly journals Red Arecanut Seed Extract as a Sustainable Corrosion Inhibitor for Aluminum Submerged in Acidic Corrodent: An Experimental Approach Towards Zero Environmental Impact

2017 ◽  
Vol 62 (3) ◽  
pp. 351-358 ◽  
Author(s):  
Narasimha Raghavendra ◽  
Jathi Ishwara Bhat
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Weight Loss ◽  
Atomic Force Microscopy ◽  
Impedance Spectroscopy ◽  
Seed Extract ◽  
Solution Temperature ◽  
Force Microscopy ◽  
Atomic Force ◽  
Scanning Electron

The effect of the red arecanut seed (RAS) extract on the corrosion of aluminum in 0.5 M hydrochloric acid environment is reported by weight loss, electrochemical (Tafel plot and impedance spectroscopy), scanning electron microscopy and atomic force microscopy studies. The weight loss study indicated that, protection efficiency of the red arecanut seed extract is directly proportional to its concentration and inversely proportional to solution temperature and aluminum contact time in the test solution. Langmuir adsorption isotherm is best fitted model explaining the adsorption of red arecanut seed extract constituents on aluminum surface in 0.5 M HCl system. The results obtained from Tafel curves indicated the mixed inhibition role of red arecanut seed extract. The impedance spectroscopy technique indicated that, red arecanut seed extract reduces the speed of aluminum corrosion by charge transfer process. The scanning electron microscopy and atomic force microscopy images of aluminum specimens clearly give clues about the adsorption of plant constituents on the surface of the aluminum metal.

scholarly journals The Double-Faced Electrostatic Behavior of PNIPAm Microgels

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1153
Author(s):  
Simona Sennato ◽  
Edouard Chauveau ◽  
Stefano Casciardi ◽  
Federico Bordi ◽  
Domenico Truzzolillo
Keyword(s):  
Charge Density ◽  
Aqueous Media ◽  
Solution Temperature ◽  
General Character ◽  
Critical Solution Temperature ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Oppositely Charged ◽  
Mobility Reversal

PNIPAm microgels synthesized via free radical polymerization (FRP) are often considered as neutral colloids in aqueous media, although it is well known, since the pioneering works of Pelton and coworkers, that the vanishing electrophoretic mobility characterizing swollen microgels largely increases above the lower critical solution temperature (LCST) of PNIPAm, at which microgels partially collapse. The presence of an electric charge has been attributed to the ionic initiators that are employed when FRP is performed in water and that stay anchored to microgel particles. Combining dynamic light scattering (DLS), electrophoresis, transmission electron microscopy (TEM) and atomic force microscopy (AFM) experiments, we show that collapsed ionic PNIPAm microgels undergo large mobility reversal and reentrant condensation when they are co-suspended with oppositely charged polyelectrolytes (PE) or nanoparticles (NP), while their stability remains unaffected by PE or NP addition at lower temperatures, where microgels are swollen and their charge density is low. Our results highlight a somehow double-faced electrostatic behavior of PNIPAm microgels due to their tunable charge density: they behave as quasi-neutral colloids at temperature below LCST, while they strongly interact with oppositely charged species when they are in their collapsed state. The very similar phenomenology encountered when microgels are surrounded by polylysine chains and silica nanoparticles points to the general character of this twofold behavior of PNIPAm-based colloids in water.

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