scholarly journals Self-assembly of tholins in environments simulating Titan liquidospheres: implications for formation of primitive coacervates on Titan

2013 ◽  
Vol 12 (4) ◽  
pp. 282-291 ◽  
Author(s):  
Jun Kawai ◽  
Seema Jagota ◽  
Takeo Kaneko ◽  
Yumiko Obayashi ◽  
Yoshitaka Yoshimura ◽  
...  
Keyword(s):  
Organic Compounds ◽  
Self Assembly ◽  
Aqueous Ammonia ◽  
Aqueous Environment ◽  
Plasma Discharges ◽  
Atmospheric Gases ◽  
Polar Solvents ◽  
Average Temperature ◽  
Magnetosphere Of Saturn ◽  
Complex Organic

AbstractTitan, the largest satellite of Saturn, has a thick atmosphere containing nitrogen and methane. A variety of organic compounds have been detected in the atmosphere, most likely produced when atmospheric gases are exposed to ultraviolet light, electrons captured by the magnetosphere of Saturn and cosmic rays. The Cassini/Huygens probe showed that the average temperature on the surface of Titan is 93.7 K, with lakes of liquid ethane and methane. Sub-surface mixtures of liquid ammonia and water may also be present. We have synthesized complex organic compounds (tholins) by exposing a mixture of nitrogen and methane to plasma discharges, and investigated their interactions with several different liquids that simulate Titan's liquidosphere. We found that coacervates formed when tholins were extracted in non-polar solvents followed by exposure to aqueous ammonia solutions. The results suggest that coacervates can self-assemble in Titan's liquidosphere which have the potential to undergo further chemical evolution. Similar processes are likely to occur in the early evolution of habitable planets when tholin-like compounds undergo phase separation into microscopic structures dispersed in a suitable aqueous environment.

scholarly journals Self-assembly processes in the prebiotic environment

2006 ◽  
Vol 361 (1474) ◽  
pp. 1809-1818 ◽  
Author(s):  
David Deamer ◽  
Sara Singaram ◽  
Sudha Rajamani ◽  
Vladimir Kompanichenko ◽  
Stephen Guggenheim
Keyword(s):  
Origin Of Life ◽  
Organic Compounds ◽  
Self Assembly ◽  
Initial Study ◽  
Aqueous Environment ◽  
Organic Solutes ◽  
Mineral Surfaces ◽  
Molecular Systems ◽  
Intermediate Temperature Range ◽  
The Origin Of Life

An important question guiding research on the origin of life concerns the environmental conditions where molecular systems with the properties of life first appeared on the early Earth. An appropriate site would require liquid water, a source of organic compounds, a source of energy to drive polymerization reactions and a process by which the compounds were sufficiently concentrated to undergo physical and chemical interactions. One such site is a geothermal setting, in which organic compounds interact with mineral surfaces to promote self-assembly and polymerization reactions. Here, we report an initial study of two geothermal sites where mixtures of representative organic solutes (amino acids, nucleobases, a fatty acid and glycerol) and phosphate were mixed with high-temperature water in clay-lined pools. Most of the added organics and phosphate were removed from solution with half-times measured in minutes to a few hours. Analysis of the clay, primarily smectite and kaolin, showed that the organics were adsorbed to the mineral surfaces at the acidic pH of the pools, but could subsequently be released in basic solutions. These results help to constrain the range of possible environments for the origin of life. A site conducive to self-assembly of organic solutes would be an aqueous environment relatively low in ionic solutes, at an intermediate temperature range and neutral pH ranges, in which cyclic concentration of the solutes can occur by transient dry intervals.

Wastewater treatment and nutrient removal in the combined reactor

1998 ◽  
Vol 38 (1) ◽  
pp. 87-95 ◽  
Author(s):  
M. Roš ◽  
J. Vrtovšek
Keyword(s):  
Organic Compounds ◽  
Industrial Wastewater ◽  
Design Procedure ◽  
Order Reaction ◽  
Treated Wastewater ◽  
Nitrification Rate ◽  
Zero Order Reaction ◽  
Aerobic Reactor ◽  
Complex Organic

A combined anaerobic anoxic aerobic reactor for the treatment of the industrial wastewater that contains nitrogen and complex organic compounds as well as its design procedure is presented. The purpose of our experiments was to find a simple methodology that would provide combined reactor design. The reactor is based on the combination of anaerobic, anoxic and aerobic process in one unit only. It was found that the HRT even under 1 hour in the anaerobic zone is long enough for the efficient transformation of complex organic compounds into readily biodegradable COD which is then used in dentrification process. In the N-NO3 concentration range 1.5-50 mg/l the denitrification rate could be expressed as half-order reaction when the CODrb was in excess. N-NO3 removal efficiency is controlled by the recycle flow from the aerobic to the anoxic zone. Nitrification rate can be expressed as first, half or zero-order reaction with respect to effluent N-NH4 concentration. Nitrification rate depends on the dissolved oxygen concentration and hydrodynamic conditions in the reactor. Case study for design of a pilot plant of the combined reactor for treatment of pre-treated pharmaceutical wastewater is shown. Characteristics of pre-treated wastewater were: COD=200 mg/l, BOD5=20 mg/l, N-Kjeldahl=80 mg/l, N-NH4=70 mg/l, N-NOx<1 mg/l, P-PO4=5 mg/l. Legal requirements for treated wastewater were: COD=<100 mg/l, BOD5<5 mg/l, N-NH4=<1 mg/l, N-NOx=<10 mg/l.

Supramolecular Self-Assembly of Nitro-incorporated Quinoxaline Framework: Insights into the Origin of Fluorescence Turn-on Response towards Benzene group of VOCs

The Analyst ◽  
2021 ◽  
Author(s):  
Megha Basak ◽  
Gopal Das
Keyword(s):  
Volatile Organic Compounds ◽  
Human Health ◽  
Organic Compounds ◽  
Self Assembly ◽  
Turn On ◽  
Volatile Organic ◽  
Fluorescence Turn On

Hazardous volatile organic compounds (VOCs) can significantly impact human health and the environment. Hence, the detection of VOCs has become foremost important. Quinoxaline-based fluorimetric probe (1) unveils a notable “Turn-On”...

Chemical Recognition and Nematocyte Excitation in a Sea Anemone

1979 ◽  
Vol 83 (1) ◽  
pp. 283-292
Author(s):  
ROGER LUBBOCK
Keyword(s):  
Chemical Composition ◽  
Organic Compounds ◽  
Mechanical Stimulation ◽  
Sea Anemone ◽  
Physical Contact ◽  
Recognition Process ◽  
Chemical Recognition ◽  
Cellular Recognition ◽  
Complex Organic ◽  
Stichodactyla Haddoni

The response of nematocytes in the anemone Stichodactyla haddoni to contact with complex organic compounds varies according to the 9ubstance concerned and in most cases according to the level of accompanying mechanical stimulation. Compounds with a proteinaceous moiety differ in their capacity to excite nematocytes, but usually tend to induce a stronger response than polysaccharides or lipids. Nematocyst discharge against foreign animals appears to be the result of a sophisticated cellular recognition process in which the nematocytes, and/or cells closely associated with them, respond to physical contact with a surface of appropriate chemical composition.

Molecularly Imprinted Polymers for Selective Adsorption of Cholesterol from Aqueous Environment

e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Francesco Puoci ◽  
Francesca Iemma ◽  
Giuseppe Cirillo ◽  
Sonia Trombino ◽  
Roberta Cassano ◽  
...  
Keyword(s):  
Molecularly Imprinted Polymers ◽  
Selective Adsorption ◽  
Aqueous Media ◽  
Aqueous Environment ◽  
Polar Solvents ◽  
Molecularly Imprinted ◽  
Imprinted Polymers ◽  
Bond Forming ◽  
Preparation And Evaluation ◽  
Templating Effect

AbstractIn this work the preparation and evaluation of molecularly imprinted polymers (MIPs) based on 2-hydroxyethylmetacrylate (HEMA) for selective recovery of cholesterol from aqueous media are reported. HEMA was used as functional monomer in order to maximize the hydrogen bond forming both in prepolymerization complex and in rebinding experiments which were performed in polar solvents; in particular, an acetonitrile:water (7:3 v/v) mixture was employed. The templating effect is clearly seen in the capacity of the synthesized polymers to bind cholesterol, and their selectivity was evaluated using two steroids quite similar to cholesterol such as progesterone and hydrocortisone which are less effectively bound by the matrices.

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