The interplay of thermodynamics and kinetics: imparting hierarchical control over film formation of self-stratified blends

Soft Matter ◽  
2020 ◽  
Vol 16 (5) ◽  
pp. 1287-1297
Author(s):  
Samantha J. Rinehart ◽  
Guangcui Yuan ◽  
Mark D. Dadmun
Keyword(s):  
Thin Films ◽  
Chain Length ◽  
Polymer Chain ◽  
Polymer Blend ◽  
Casting Speed ◽  
Film Formation ◽  
Hierarchical Control ◽  
Neutron Reflectivity ◽  
Thermodynamics And Kinetics ◽  
Blend Composition

Neutron reflectivity provide a thorough understanding of the balance of thermodynamic and kinetic factors that influence the stratification of spin cast polymer blend thin films, including blend composition, polymer chain length, and casting speed.

Spontaneous bilayer phase separations of spin-coated polymer blend thin films: A neutron reflectivity study

2016 ◽  
Vol 24 (12) ◽  
pp. 1105-1110 ◽  
Author(s):  
Jaseung Koo ◽  
Sushil Satija ◽  
Jeong-Soo Lee ◽  
Young-Soo Seo
Keyword(s):  
Thin Films ◽  
Polymer Blend ◽  
Neutron Reflectivity ◽  
Phase Separations

Lipid Polymorphism and Virus-Membrane Fusion as Observed in Vitrified Thin Films by Cryo-Electron Microscopy

1990 ◽  
Vol 48 (1) ◽  
pp. 492-493
Author(s):  
P.M. Frederik ◽  
K.N.J. Burger ◽  
M.C.A. Stuart ◽  
A.J. Verkleij
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Membrane Fusion ◽  
Film Formation ◽  
Molar Ratio ◽  
Influenza B ◽  
Complex Structures ◽  
Type Ii ◽  
Suspended Material ◽  
Cryo Electron Microscopy

Cellular membranes are often composed of phospholipid mixtures in which one or more components have a tendency to adopt a type II non-bilayer lipid structure such as the inverted hexagonal (H||) phase. The formation of a type II non-bilayer intermediate, the inverted lipid micel is proposed as the initial step in membrane fusion (Verkleij 1984, Siegel, 1986). In the various forms of cellular transport mediated by carrier vesicles (e.g. exocytosis, endocytosis) the regulation of membrane fusion, and hence of inverted lipid micel formation, is of vital importance.We studied the phase behaviour of simple and complex lipid mixtures by cryo-electron microscopy to gain more insight in the ultrastructure of different lipid phases (e.g. Pβ’, Lα, H||) and in the complex membrane structures arising after Lα < - > H|| phase changes (e.g. isotropic, cubic). To prepare hydrated thin films a 700 mesh hexagonal grid (without supporting film) was dipped into and withdrawn from a liposome suspension. The excess fluid was blotted against filter paper and the thin films that form between the bars of the specimen grid were immediately (within 1 second) vitrified by plunging of the carrier grids into ethane cooled to its melting point by liquid nitrogen (Dubochet et al., 1982). Surface active molecules such as phospholipids play an important role in the formation and thinning of these aqueous thin films (Frederik et al., 1989). The formation of two interfacial layers at the air-water interfaces requires transport of surface molecules from the suspension as well as the orientation of these molecules at the interfaces. During the spontaneous thinning of the film the interfaces approach each other, initially driven by capillary forces later by Van der Waals attraction. The process of thinning results in the sorting by size of the suspended material and is also accompanied by a loss of water from the thinner parts of the film. This loss of water may result in the concentration and eventually in partial dehydration of suspended material even if thin films are vitrified within 1 sec after their formation. Film formation and vitrification were initiated at temperatures between 20-60°C by placing die equipment in an incubator provided widi port holes for the necessary manipulations. Unilamellar vesicles were made from dipalmitoyl phosphatidyl choline (DPPC) by an extrusion method and showed a smooth (Lα) or a rippled (PB’.) structure depending on the temperature of the suspensions and the temperature of film formation (50°C resp. 39°C) prior to vitrification. The thermotropic phases of hydrated phospholipids are thus faithfully preserved in vitrified thin films (fig. a,b). Complex structures arose when mixtures of dioleoylphosphatidylethanol-amine (DOPE), dioleoylphosphatidylcholine (DOPC) and cholesterol (molar ratio 3/1/2) are heated and used for thin film formation. The tendency of DOPE to adopt the H|| phase is responsible for the formation of complex structures in this lipid mixture. Isotropic and cubic areas (fig. c,d) having a bilayer structure are found in coexistence with H|| cylinders (fig. e). The formation of interlamellar attachments (ILA’s) as observed in isotropic and cubic structures is also thought to be of importance in biological fusion events. Therefore the study of the fusion activity of influenza B virus with liposomes (DOPE/DOPC/cholesterol/ganglioside in a molar ratio 1/1/2/0.2) was initiated. At neutral pH only adsorption of virus to liposomes was observed whereas 2 minutes after a drop in pH (7.4 - > 5.4) fusion between virus and liposome membranes was demonstrated (fig. f). The micrographs illustrate the exciting potential of cryo-electron microscopy to study lipid-lipid and lipid-protein interactions in hydrated specimens.

Preparation and Characterization of Polymer Blend (PVA/PEO) Filled with Methyl Orange Thin Films

2018 ◽  
Vol 14 (2) ◽  
pp. 221-234
Author(s):  
Ahmed Namah Mohamed ◽  
◽  
Jafer Fahdel Odah ◽  
Haider Tawfiq Naeem
Keyword(s):  
Thin Films ◽  
Methyl Orange ◽  
Polymer Blend

Effect of surface properties and polymer chain length on polymer adsorption in solution

2021 ◽  
Vol 155 (3) ◽  
pp. 034701
Author(s):  
Emily Y. Lin ◽  
Amalie L. Frischknecht ◽  
Karen I. Winey ◽  
Robert A. Riggleman
Keyword(s):  
Surface Properties ◽  
Chain Length ◽  
Polymer Chain ◽  
Polymer Adsorption ◽  
Effect Of Surface

Effect of Polymer Chain Length on the Superlattice Assembly of Functionalized Gold Nanoparticles

Langmuir ◽  
2021 ◽  
Author(s):  
Hyeong Jin Kim ◽  
Wenjie Wang ◽  
Honghu Zhang ◽  
Guillaume Freychet ◽  
Benjamin M. Ocko ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Chain Length ◽  
Polymer Chain ◽  
Functionalized Gold Nanoparticles

Neutron reflectivity study of thin films of hydrogen-bonded polymer blends: influence of annealing on composition profile

1992 ◽  
Vol 25 (10) ◽  
pp. 2619-2623 ◽  
Author(s):  
Lei Jong ◽  
Eli M. Pearce ◽  
T. K. Kwei ◽  
W. A. Hamilton ◽  
G. S. Smith ◽  
...  
Keyword(s):  
Thin Films ◽  
Polymer Blends ◽  
Composition Profile ◽  
Neutron Reflectivity ◽  
Hydrogen Bonded

A facile room temperature chemical transformation approach for binder-free thin film formation of Ag2Te and lithiation/delithiation chemistry of the film

2016 ◽  
Vol 45 (43) ◽  
pp. 17312-17318 ◽  
Author(s):  
Eun-Kyung Kim ◽  
Dasom Park ◽  
Nabeen K. Shrestha ◽  
Jinho Chang ◽  
Cheol-Woo Yi ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Aqueous Solution ◽  
Ion Exchange ◽  
Chemical Transformation ◽  
Room Temperature ◽  
Film Formation ◽  
Synthetic Method ◽  
Binder Free ◽  
Thin Film Formation

An aqueous solution based synthetic method for binder-free Ag2Te thin films using ion exchange induced chemical transformation of Ag/AgxO thin films.

Construction of the state diagram of polymer blend thin films using differential AC chip calorimetry

Polymer ◽  
2011 ◽  
Vol 52 (19) ◽  
pp. 4277-4283 ◽  
Author(s):  
Nicolaas-Alexander Gotzen ◽  
Guy Van Assche ◽  
Bruno Van Mele
Keyword(s):  
Thin Films ◽  
Polymer Blend ◽  
State Diagram ◽  
The State ◽  
Chip Calorimetry
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