scholarly journals Templating the morphology of soft microgel assemblies using a nanolithographic 3D-printed membrane

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
John Linkhorst ◽  
Jonas Lölsberg ◽  
Sebastian Thill ◽  
Johannes Lohaus ◽  
Arne Lüken ◽  
...  

AbstractFilter cake formation is the predominant phenomenon limiting the filtration performance of membrane separation processes. However, the filter cake’s behavior at the particle scale, which determines its overall cake behavior, has only recently come into the focus of scientists, leaving open questions about its formation and filtration behavior. The present study contributes to the fundamental understanding of soft filter cakes by analyzing the influence of the porous membrane’s morphology on crystal formation and the compaction behavior of soft filter cakes under filtration conditions. Microfluidic chips with nanolithographic imprinted filter templates were used to trigger the formation of crystalline colloidal filter cakes formed by soft microgels. The soft filter cakes were observed via confocal laser scanning microscopy (CLSM) under dead-end filtration conditions. Colloidal crystal formation in the cake, as well as their compaction behavior, were analyzed by optical visualization and pressure data. For the first time, we show that exposing the soft cake to a crystalline filter template promotes the formation of colloidal crystallites and that soft cakes experience gradient compression during filtration.

2017 ◽  
Author(s):  
René M. Williams ◽  
Loreta A. Muscarella ◽  
Dina Petrova ◽  
Rebecca Jorge Cervasio ◽  
Aram Farawar ◽  
...  

Mixed cationic lead perovskites containing formamidinium and methylammonium can be stabilized by incorporating ZnI<sub>2 </sub>as an “internal desiccant”. Next to prolonged stability under ambient conditions we show with XRD that the use of an additive, 3-chloropropyl ammonium chloride, influences crystal formation by orienting the crystals. These ~500 nm crystals show individual photoluminescent behavior in thin films and have a longer photoluminescence lifetime at the grain boundaries as compared to the center of the crystal or relative to un-doped materials without the additive made under identical conditions. Charges recombine slower at the edges of the crystals as observed with confocal laser scanning microscopy


Author(s):  
Loreta A. Muscarella ◽  
Dina Petrova ◽  
Rebecca Jorge Cervasio ◽  
Aram Farawar ◽  
Olivier Lugier ◽  
...  

Mixed cationic lead perovskites containing formamidinium and methylammonium can be stabilized by incorporating ZnI<sub>2 </sub>as an “internal desiccant”. Next to prolonged stability under ambient conditions we show with XRD that the use of an additive, 3-chloropropyl ammonium chloride, influences crystal formation by orienting the crystals. These ~500 nm crystals show individual photoluminescent behavior in thin films and have a longer photoluminescence lifetime at the grain boundaries as compared to the center of the crystal or relative to un-doped materials without the additive made under identical conditions. Charges recombine slower at the edges of the crystals as observed with confocal laser scanning microscopy. The material can also be prepared as a black precursor powder by a solid-solid reaction under ambient conditions.


2017 ◽  
Author(s):  
Loreta A. Muscarella ◽  
Dina Petrova ◽  
Rebecca Jorge Cervasio ◽  
Aram Farawar ◽  
Olivier Lugier ◽  
...  

Mixed cationic lead perovskites containing formamidinium and methylammonium can be stabilized by incorporating ZnI<sub>2 </sub>as an “internal desiccant”. Next to prolonged stability under ambient conditions we show with XRD that the use of an additive, 3-chloropropyl ammonium chloride, influences crystal formation by orienting the crystals. These ~500 nm crystals show individual photoluminescent behavior in thin films and have a longer photoluminescence lifetime at the grain boundaries as compared to the center of the crystal or relative to un-doped materials without the additive made under identical conditions. Charges recombine slower at the edges of the crystals as observed with confocal laser scanning microscopy. The material can also be prepared as a black precursor powder by a solid-solid reaction under ambient conditions.


Author(s):  
Thomas M. Jovin ◽  
Michel Robert-Nicoud ◽  
Donna J. Arndt-Jovin ◽  
Thorsten Schormann

Light microscopic techniques for visualizing biomolecules and biochemical processes in situ have become indispensable in studies concerning the structural organization of supramolecular assemblies in cells and of processes during the cell cycle, transformation, differentiation, and development. Confocal laser scanning microscopy offers a number of advantages for the in situ localization and quantitation of fluorescence labeled targets and probes: (i) rejection of interfering signals emanating from out-of-focus and adjacent structures, allowing the “optical sectioning” of the specimen and 3-D reconstruction without time consuming deconvolution; (ii) increased spatial resolution; (iii) electronic control of contrast and magnification; (iv) simultanous imaging of the specimen by optical phenomena based on incident, scattered, emitted, and transmitted light; and (v) simultanous use of different fluorescent probes and types of detectors.We currently use a confocal laser scanning microscope CLSM (Zeiss, Oberkochen) equipped with 3-laser excitation (u.v - visible) and confocal optics in the fluorescence mode, as well as a computer-controlled X-Y-Z scanning stage with 0.1 μ resolution.


Author(s):  
M. H. Chestnut ◽  
C. E. Catrenich

Helicobacter pylori is a non-invasive, Gram-negative spiral bacterium first identified in 1983, and subsequently implicated in the pathogenesis of gastroduodenal disease including gastritis and peptic ulcer disease. Cytotoxic activity, manifested by intracytoplasmic vacuolation of mammalian cells in vitro, was identified in 55% of H. pylori strains examined. The vacuoles increase in number and size during extended incubation, resulting in vacuolar and cellular degeneration after 24 h to 48 h. Vacuolation of gastric epithelial cells is also observed in vivo during infection by H. pylori. A high molecular weight, heat labile protein is believed to be responsible for vacuolation and to significantly contribute to the development of gastroduodenal disease in humans. The mechanism by which the cytotoxin exerts its effect is unknown, as is the intracellular origin of the vacuolar membrane and contents. Acridine orange is a membrane-permeant weak base that initially accumulates in low-pH compartments. We have used acridine orange accumulation in conjunction with confocal laser scanning microscopy of toxin-treated cells to begin probing the nature and origin of these vacuoles.


TAPPI Journal ◽  
2010 ◽  
Vol 9 (10) ◽  
pp. 7-15
Author(s):  
HANNA KOIVULA ◽  
DOUGLAS BOUSFIELD ◽  
MARTTI TOIVAKKA

In the offset printing process, ink film splitting has an important impact on formation of ink filaments. The filament size and its distribution influence the leveling of ink and hence affect ink setting and the print quality. However, ink filaments are difficult to image due to their short lifetime and fine length scale. Due to this difficulty, limited work has been reported on the parameters that influence filament size and methods to characterize it. We imaged ink filament remains and quantified some of their characteristics by changing printing speed, ink amount, and fountain solution type. Printed samples were prepared using a laboratory printability tester with varying ink levels and operating settings. Rhodamine B dye was incorporated into fountain solutions to aid in the detection of the filaments. The prints were then imaged with a confocal laser scanning microscope (CLSM) and images were further analyzed for their surface topography. Modeling of the pressure pulses in the printing nip was included to better understand the mechanism of filament formation and the origin of filament length scale. Printing speed and ink amount changed the size distribution of the observed filament remains. There was no significant difference between fountain solutions with or without isopropyl alcohol on the observed patterns of the filament remains.


2012 ◽  
Vol 11 (3) ◽  
pp. 669-674 ◽  
Author(s):  
Szabolcs Szilveszter ◽  
Botond Raduly ◽  
Szilard Bucs ◽  
Beata Abraham ◽  
Szabolcs Lanyi ◽  
...  

2009 ◽  
Vol 18 (1) ◽  
pp. 11-16
Author(s):  
E.V. Soldatenko ◽  
A.A. Petrov

The morphology of the copulatory apparatus and associated cuticular structures in Planorbis planorbis was studied by light microscopy, SEM, TEM and confocal laser scanning microscopy. The significance of these cuticular structures for the taxonomic status of the species and for the systematics of the family Planorbidae in general is discussed.


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