Ordered Water Layer on the Macroscopically Hydrophobic Fluorinated Polymer Surface and Its Ultrafast Vibrational Dynamics

2021 ◽  
Author(s):  
Jiahui Zhang ◽  
Junjun Tan ◽  
Ruoqi Pei ◽  
Shuji Ye ◽  
Yi Luo
Keyword(s):  
Polymer Surface ◽  
Water Layer ◽  
Vibrational Dynamics ◽  
Fluorinated Polymer ◽  
Ordered Water

scholarly journals Droplet clusters: nature-inspired biological reactors and aerosols

2019 ◽  
Vol 377 (2150) ◽  
pp. 20190121 ◽  
Author(s):  
Alexander A. Fedorets ◽  
Edward Bormashenko ◽  
Leonid A. Dombrovsky ◽  
Michael Nosonovsky
Keyword(s):  
Polymer Surface ◽  
Water Layer ◽  
Breath Figures ◽  
Self Organized ◽  
Droplet Cluster ◽  
Active Research ◽  
Living Nature ◽  
And Migration ◽  
Hexagonally Ordered

Condensed microdroplets play a prominent role in living nature, participating in various phenomena, from water harvesting by plants and insects to microorganism migration in bioaerosols. Microdroplets may also form regular self-organized patterns, such as the hexagonally ordered breath figures on a solid surface or levitating monolayer droplet clusters over a locally heated water layer. While the breath figures have been studied since the nineteenth century, they have found a recent application in polymer surface micropatterning (e.g. for superhydrophobicity). Droplet clusters were discovered in 2004, and they are the subject of active research. Methods to control and stabilize droplet clusters make them suitable for the in situ analysis of bioaerosols. Studying life in bioaerosols is important for understanding microorganism origins and migration; however, direct observation with traditional methods has not been possible. We report preliminary results on direct in situ observation of microorganisms in droplet clusters. We also present a newly observed transition between the hexagonally ordered and chain-like states of a droplet cluster. This article is part of the theme issue ‘Bioinspired materials and surfaces for green science and technology (part 2)’.

scholarly journals Targeting Mitochondria for Cancer Treatment – Two Types of Mitochondrial Dysfunction

2014 ◽  
Vol 115 (3-4) ◽  
pp. 104-119 ◽  
Author(s):  
Jiří Pokorný ◽  
Jan Pokorný ◽  
Jitka Kobilková ◽  
Anna Jandová ◽  
Jan Vrba ◽  
...  
Keyword(s):  
Membrane Potential ◽  
Cancer Treatment ◽  
Mitochondrial Dysfunction ◽  
Cancer Cells ◽  
Oxidative Metabolism ◽  
Warburg Effect ◽  
Water Layer ◽  
Frequency Spectra ◽  
Reverse Warburg Effect ◽  
Ordered Water

Two basic types of cancers were identified – those with the mitochondrial dysfunction in cancer cells (the Warburg effect) or in fibroblasts supplying energy rich metabolites to a cancer cell with functional mitochondria (the reverse Warburg effect). Inner membrane potential of the functional and dysfunctional mitochondria measured by fluorescent dyes (e.g. by Rhodamine 123) displays low and high values (apparent potential), respectively, which is in contrast to the level of oxidative metabolism. Mitochondrial dysfunction (full function) results in reduced (high) oxidative metabolism, low (high) real membrane potential, a simple layer (two layers) of transported protons around mitochondria, and high (low) damping of microtubule electric polar vibrations. Crucial modifications are caused by ordered water layer (exclusion zone). For the high oxidative metabolism one proton layer is at the mitochondrial membrane and the other at the outer rim of the ordered water layer. High and low damping of electric polar vibrations results in decreased and increased electromagnetic activity in cancer cells with the normal and the reverse Warburg effect, respectively. Due to nonlinear properties the electromagnetic frequency spectra of cancer cells and transformed fibroblasts are shifted in directions corresponding to their power deviations resulting in disturbances of interactions and escape from tissue control. The cancer cells and fibroblasts of the reverse Warburg effect tumors display frequency shifts in mutually opposite directions resulting in early generalization. High oxidative metabolism conditions high aggressiveness. Mitochondrial dysfunction, a gate to malignancy along the cancer transformation pathway, forms a narrow neck which could be convenient for cancer treatment.

Polymer surface and thin film vibrational dynamics of poly(methyl methacrylate), polybutadiene, and polystyrene

2008 ◽  
Vol 129 (4) ◽  
pp. 044906 ◽  
Author(s):  
Miriam A. Freedman ◽  
James S. Becker ◽  
A. W. Rosenbaum ◽  
S. J. Sibener
Keyword(s):  
Thin Film ◽  
Methyl Methacrylate ◽  
Polymer Surface ◽  
Vibrational Dynamics ◽  
Poly Methyl Methacrylate

Effect of Surface Morphology on the Ordered Water Layer at Room Temperature

2011 ◽  
Vol 115 (7) ◽  
pp. 3018-3024 ◽  
Author(s):  
Chunlei Wang ◽  
Bo Zhou ◽  
Peng Xiu ◽  
Haiping Fang
Keyword(s):  
Surface Morphology ◽  
Room Temperature ◽  
Water Layer ◽  
Ordered Water ◽  
Effect Of Surface

Adsorption of Gaseous Propylamine on Films of Polypyrrole in Different Oxidation States

1999 ◽  
Vol 64 (1) ◽  
pp. 1-12
Author(s):  
Vítězslav Papež ◽  
Šárka Brodská ◽  
Jan Langmaier ◽  
Zdeněk Samec ◽  
Karin Potje-Kamloth
Keyword(s):  
Work Function ◽  
Gas Phase ◽  
Quartz Crystal ◽  
Co Adsorption ◽  
Polymer Surface ◽  
Water Layer ◽  
Acetonitrile Solution ◽  
Water Vapour Pressure ◽  
Kelvin Probe ◽  
Adsorption Of Water

Quartz crystal microbalance and Kelvin probe were used to investigate the interaction between propylamine (PrNH2) vapour and polypyrrole (PPy) films. The films were prepared by oxidative electropolymerization of pyrrole on a platinum electrode in acetonitrile solution. The nature of interaction is strongly influenced by the oxidation state of the film and co-adsorption of water. On the surface of the oxidized PPy, water adsorbs to form a multilayer. The work function increase of the Pt/PPy electrode exposed to both water and PrNH2 vapoures was attributed to the PrNH2 dissolution and dissociation within the water layer followed by the formatted PrNH3+ cation adsorption on the liquid surface with the alkyl group facing the gas phase. On the contrary, the water adsorption on the reduced PPy is rather weak and the work function decrease observed at the PrNH2 exposure might be connected with the neutral molecules adsorption directly on the polymer surface. The water co-adsorption is documented by a drop in the adsorption of PrNH2 upon lowering the water vapour pressure in the gas phase.

Roughness measurements of nonlinear optical polymer films by scanning tunneling microscopy

1989 ◽  
Vol 47 ◽  
pp. 22-23
Author(s):  
I. H. Musselman ◽  
R.-T. Chen ◽  
P. E. Russell
Keyword(s):  
Surface Roughness ◽  
Scanning Tunneling Microscopy ◽  
Nonlinear Optical ◽  
Polymer Surface ◽  
Light Extinction ◽  
Scanning Tunneling ◽  
Silicon Substrates ◽  
Tunneling Microscopy ◽  
Optical Polymer ◽  
Total Light

Scanning tunneling microscopy (STM) has been used to characterize the surface roughness of nonlinear optical (NLO) polymers. A review of STM of polymer surfaces is included in this volume. The NLO polymers are instrumental in the development of electrooptical waveguide devices, the most fundamental of which is the modulator. The most common modulator design is the Mach Zehnder interferometer, in which the input light is split into two legs and then recombined into a common output within the two dimensional waveguide. A π phase retardation, resulting in total light extinction at the output of the interferometer, can be achieved by changing the refractive index of one leg with respect to the other using the electrooptic effect. For best device performance, it is essential that the NLO polymer exhibit minimal surface roughness in order to reduce light scattering. Scanning tunneling microscopy, with its high lateral and vertical resolution, is capable of quantifying the NLO polymer surface roughness induced by processing. Results are presented below in which STM was used to measure the surface roughness of films produced by spin-coating NLO-active polymers onto silicon substrates.

Imaging nanostructures on ablated kapton polymide

1993 ◽  
Vol 51 ◽  
pp. 872-873
Author(s):  
Daniel L. Callahan ◽  
H. M. Phillips ◽  
R. Sauerbrey
Keyword(s):  
Electron Microscopy ◽  
Polymer Surface ◽  
Grating Period ◽  
Laser Wavelength ◽  
Integrated Devices ◽  
Transmission Electron ◽  
Excimer Laser Irradiation ◽  
Produce Line ◽  
Line Patterns ◽  
Anisotropic Conduction

Excimer laser irradiation has been used to interferometrically ablate submicron line patterns on to Kapton polyimide. Such patterned material may exhibit highly anisotropic conduction as was predicted from previous studies showing enhanced conductivity from uniformly ablated material. We are currently exploiting this phenomenon to create integrated devices using conventional polymers as both dielectrics and conductors. Extensive scanning electron microscopy (SEM) and limited transmission electron microscopy (TEM) have been conducted in order to characterize the morphology of such patterned nanostructures as a function of processing conditions.The ablation technique employed produces an interference pattern on the polymer surface of period equal to half that of a diffraction grating period, independent of the laser wavelength. In these experiments, a 328 nm grating has been used to produce line patterns of 164 nm line-spacings as shown in Figures 1 and 2. A 200 Å Au coating has been used to both prevent charging and, perhaps more importantly, enhance contrast.

Imaging of polymer single crystals in low-voltage, high-resolution scanning electron microscopy

1990 ◽  
Vol 48 (4) ◽  
pp. 1106-1107
Author(s):  
W.W. Adams ◽  
G. Price ◽  
A. Krause
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Resolution ◽  
Single Crystals ◽  
Low Voltage ◽  
Polymer Surface ◽  
Beam Current ◽  
Image Features ◽  
First Results ◽  
Scanning Electron

It has been shown that there are numerous advantages in imaging both coated and uncoated polymers in scanning electron microscopy (SEM) at low voltages (LV) from 0.5 to 2.0 keV compared to imaging at conventional voltages of 10 to 20 keV. The disadvantages of LVSEM of degraded resolution and decreased beam current have been overcome with the new generation of field emission gun SEMs. In imaging metal coated polymers in LVSEM beam damage is reduced, contrast is improved, and charging from irregularly shaped features (which may be unevenly coated) is reduced or eliminated. Imaging uncoated polymers in LVSEM allows direct observation of the surface with little or no charging and with no alterations of surface features from the metal coating process required for higher voltage imaging. This is particularly important for high resolution (HR) studies of polymers where it is desired to image features 1 to 10 nm in size. Metal sputter coating techniques produce a 10 - 20 nm film that has its own texture which can obscure topographical features of the original polymer surface. In examining thin, uncoated insulating samples on a conducting substrate at low voltages the effect of sample-beam interactions on image formation and resolution will differ significantly from the effect at higher accelerating voltages. We discuss here sample-beam interactions in single crystals on conducting substrates at low voltages and also present the first results on HRSEM of single crystal morphologies which show some of these effects.

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