Self-assembled mesoscopic surface domains of fluorocarbon–hydrocarbon diblocks can form at zero surface pressure: tilting of solid-like hydrocarbon moieties compensates for cross-section mismatch with fluorocarbon moieties

2017 ◽  
Vol 19 (35) ◽  
pp. 23809-23816 ◽  
Author(s):  
Christian Schwieger ◽  
Xianhe Liu ◽  
Marie Pierre Krafft
Keyword(s):  
Cross Section ◽  
Surface Pressure ◽  
Alkyl Chains ◽  
Self Assembled ◽  
Surface Domains

Surface domains of C8F17C16H33 exist at zero surface pressure with solid-like alkyl chains stretched in an all-trans configuration, shown using IRRAS.

Quinacridone-pyridine dicarboxylic acid based donor–acceptor supramolecular nanobelts for significantly enhanced photocatalytic hydrogen production

2020 ◽  
Vol 8 (3) ◽  
pp. 930-934
Author(s):  
Mengyu Xu ◽  
Kangyi Kong ◽  
Haoran Ding ◽  
Yanmeng Chu ◽  
Shicong Zhang ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Dicarboxylic Acid ◽  
Photocatalytic Hydrogen Production ◽  
Alkyl Chains ◽  
Pyridine Dicarboxylic Acid ◽  
Donor Acceptor ◽  
Self Assembled

Self-assembled nanobelt photocatalysts with quinacridone containing different alkyl chains as donor and pyridine dicarboxylic acid as acceptor were firstly developed for H2 evolution. SQAP-C4 without cocatalyst of Pt exhibited HER of 656 μmol h−1 g−1.

scholarly journals First in situ vesicular self-assembly of ‘binols’ generated by a two-component aerobic oxidation reaction

RSC Advances ◽  
2018 ◽  
Vol 8 (51) ◽  
pp. 29155-29163 ◽  
Author(s):  
Braja G. Bag ◽  
Subrata Ghorai ◽  
Saikat K. Panja ◽  
Shaishab K. Dinda ◽  
Koushik Paul
Keyword(s):  
Self Assembly ◽  
Oxidation Reaction ◽  
Aerobic Oxidation ◽  
Alkyl Chains ◽  
Two Component ◽  
Donor Acceptor ◽  
Self Assembled ◽  
Naphthol Derivatives

Binol derivatives, obtained by aerobic coupling of two 2-naphthol derivatives having H-bond donor–acceptor groups and appended alkyl chains, spontaneously self-assembled in situ yielding vesicular self-assemblies and gels.

Temporal cross-section for carrier capture by self-assembled quantum dots

2000 ◽  
Vol 53 (1-4) ◽  
pp. 241-244 ◽  
Author(s):  
S. Raymond ◽  
S. Fafard ◽  
K. Hinzer ◽  
S. Charbonneau ◽  
J.L. Merz
Keyword(s):  
Quantum Dots ◽  
Cross Section ◽  
Carrier Capture ◽  
Self Assembled

Physicochemical Characterization of Tetraether Lipids from Thermoplasma acidophilum. II. Film Balance Studies on the Monomolecular Organization of the Main Glycophospholipid in Monofilms

1985 ◽  
Vol 40 (3-4) ◽  
pp. 219-222 ◽  
Author(s):  
Christoph Strobl ◽  
Lambert Six ◽  
Klaus Heckmann ◽  
Birgit Henkel ◽  
Klaus Ring
Keyword(s):  
Surface Pressure ◽  
High Surface ◽  
Physicochemical Characterization ◽  
Thermoplasma Acidophilum ◽  
Alkyl Chains ◽  
Head Groups ◽  
Air Water Interface ◽  
Tetraether Lipids ◽  
High Surface Pressure

The bipolar main tetraether lipid (MPL) of Thermoplasma acidophilum has been shown to form typical liquid expanded films at the air-water interface. The limiting molecular area at the collaps pressure is approximately Ac=73 Å2 per molecule. Monopolar aiphytanyl diether lipids were found to occupy the same area at high surface pressure as MPL. Thus, it was concluded that in the monofilm only one of the two polar headgroups of the MPL molecules is hydrated, i.e. that the single MPL molecules arc oriented upright. The packing properties of MPT. in the monofilm are determined by the properties of the branched alkyl chains only; the polar head groups do not contribute to the space requirement in the film. The collaps pressure of the MPL film is approximately 39 mN m-1 at 8°C. At a surface pressure of π = 30 mN m-1 and 20 °C the film is stable for many hours.

Measurement of the Mean Pressure Distribution About a Double-wedge Strut in Turbulent Shear Flow

1974 ◽  
Vol 25 (3) ◽  
pp. 155-364 ◽  
Author(s):  
J T Turner ◽  
M H Turner ◽  
K J Williams
Keyword(s):  
Shear Flow ◽  
Cross Section ◽  
Drag Force ◽  
Surface Pressure ◽  
Velocity Variation ◽  
Flow Conditions ◽  
Double Wedge ◽  
Maximum Thickness ◽  
Pressure Distributions ◽  
Upstream Flow

SummarySurface pressure distributions have been measured on a cylinder with a double-wedge cross section in a two-dimensional channel flow. The flow is sheared in the direction of the cylinder axis, using a grid of parallel wires with variable spacing, in order to simulate the type of geometry and velocity variation which occur for annulus support struts in turbomachines. The strut had a 38° included angle at the leading and trailing edges and an aspect ratio of 1.33 based on the maximum thickness. This was fixed between the parallel walls of a rectangular wind tunnel with end leakage eliminated. Surface pressure distributions were measured over a Reynolds number range of 0.5 × 105 to 1.5 × 105 for three different shear flow conditions. Despite the presence of sharp edges at the mid-chord position, delayed boundary-layer separation beyond the plane of maximum thickness has been found for sufficiently high spanwise shear in the upstream flow. Surprisingly, therefore, some similarity with previous results for struts of circular cross section appears to exist. The influence of the shear flow conditions on the pressure drag force has been determined by numerical integration of the data. Only a slight dependence on the upstream flow conditions is found, although the effect of secondary velocity components may still be observed if the spanwise variations in the local drag force are examined.

Preparation and Properties of Surfactant Complexes of Ruthenium(II)

1979 ◽  
Vol 32 (7) ◽  
pp. 1453 ◽  
Author(s):  
O Johansen ◽  
C Kowala ◽  
AWH Mau ◽  
WHF Sasse
Keyword(s):  
Solid State ◽  
Surface Pressure ◽  
Luminescence Intensity ◽  
Crystal Packing ◽  
Emission Spectra ◽  
Quantum Yields ◽  
Alkyl Chains ◽  
Pressure Area ◽  
Bimolecular Quenching ◽  
Chain Lengths

New surfactant complexes RuM2L2+ have been prepared where M is 2,2'-bipyridyl or o-phenanthro- line and L is one of the 4-alkyl-4'-methyl-2,2'-bipyridyls (8a)-(8e), or one of the 4,4'-dialkyl-2,2'- bipyridyls (9a)-(9e), or 1,1'-(2,2'-bipyridyl-4,4'-diyl)bis(nonadecan-1-one). This diketone was pre- pared from 2,2'-bipyridyl-4,4'-dicarboxylic acid and dioctadecylcadmium; the dialkylbipyridyls were obtained by condensing 4,4'-dimethyl-2,2'-bipyridyl with 5-alkylthiopen-2-carbaldehydes, followed by desulfurization with W5 Raney nickel. Several properties of the new complexes have been compared with those of bis(2,Y-bipyridyl)(dioctadecyl 2,2'-bipyridyl-4,4'-dicarboxy1ate)ruthenium dication (2). Monolayers have been prepared and characterized by surface-pressure area curves; film com- pressibilities and stabilities are related to the lengths of the alkyl chains and to subphase composition. Absorption and emission spectra have been examined. The quantum yields and lifetimes of emission are similar in alcohol and water; with monolayer assemblies they are dependent on subphase com- position, and in the solid state they vary between 0.03-0.18 for Φ and 0.5-1.5 μs for τ, according to the chain lengths, which appear to affect crystal packing. Oxygen quenched the luminescence of solutions and supported monolayers reversibly; Stern- Volmer constants and bimolecular quenching constants are given for: diester complex (2), diketone complex (6), dialkylbipyridyl complexes (5). Except with (2) the original luminescence intensity was restored by drying. Hydrogen was not detected following irradiation with visible light of supported monolayers of pure complexes immersed in water.

Effects of Geometric Parameters on the Inner Surface Pressure of Elbow Pipe and the Establishment of Pressure Model

2012 ◽  
Vol 252 ◽  
pp. 111-115
Author(s):  
Xiao Yang Lu ◽  
Xiao Li Lu ◽  
Li Li Huang ◽  
Jin Ming Liu ◽  
Ying Yue Liu ◽  
...  
Keyword(s):  
Cross Section ◽  
Surface Pressure ◽  
Structural Design ◽  
Geometric Parameters ◽  
Computational Formula ◽  
Bending Angle ◽  
Oil Pipeline ◽  
Inner Surface ◽  
Fluent Software ◽  
Inner Diameter

Elbows of oil pipeline were adopted to study the effect of the variation of the geometric parameters of the inner diameter d, bending degree k =R/d and bending angle A on the distribution regularity of the inner surface pressure, with the simulation by the FLUENT software. Based on the analysis, the pressure computational formula on the dangerous cross section α=45° was built by using 1stOpt software. The values computed by the formula agree well with the ones simulated by FLUENT, which lays the groundwork for strength check and structural design of the elbow pipe.

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