Ubiquity of complex coacervation of DNA and proteins in aqueous solution

Soft Matter ◽  
2020 ◽  
Vol 16 (41) ◽  
pp. 9525-9533
Author(s):  
Priyanka Kaushik ◽  
Pankaj K. Pandey ◽  
V. K. Aswal ◽  
H. B. Bohidar
Keyword(s):  
Aqueous Solution ◽  
Interpolymer Complex ◽  
Complex Coacervation ◽  
Soluble Complex ◽  
Insoluble Complex

Complex coacervation follows the signature pathway defined by the onset of formation of interpolymer complex at rc, soluble complex at rφ, and insoluble complex at rprecip.

scholarly journals Thermo-Responsive Behavior of Mixed Aqueous Solution of Hydrophilic Polymer with Pendant Phosphorylcholine Group and Poly(Acrylic Acid)

Polymers ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 148
Author(s):  
Hirokazu Fukumoto ◽  
Kazuhiko Ishihara ◽  
Shin-Ichi Yusa
Keyword(s):  
Aqueous Solution ◽  
Acrylic Acid ◽  
Solution Temperature ◽  
Interpolymer Complex ◽  
Mixed Aqueous Solution ◽  
Upper Critical Solution Temperature ◽  
Acidic Conditions ◽  
Decreasing Ph ◽  
Increasing Temperature ◽  
Poly Acrylic Acid

A mixed aqueous solution of hydrophilic poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC) and poly(acrylic acid) (PAAc) becomes cloudy under acidic conditions at room temperature. The pendant carboxylic acid groups in PAAc form hydrogen bonds with the ester and phosphate groups in PMPC. While the polymers aggregate under acidic conditions, neither one associate under basic conditions because of the deprotonation of the pendant carboxy groups in PAAc. We observed that the interpolymer complex formed from PMPC, and PAAc was dissociated in aqueous solutions with increasing temperature, which is an upper critical solution temperature behavior. With increasing temperature, the molecular motion increased to dissociate the interpolymer complex. The phase transition temperature increased with increasing polymer and salt concentrations, and with decreasing pH.

THE POLAROGRAPHY OF THE MAGNESIUM-ALIZARIN SYSTEM

1963 ◽  
Vol 41 (7) ◽  
pp. 1695-1702 ◽  
Author(s):  
D. G. Brewer ◽  
John A. Page
Keyword(s):  
Aqueous Solution ◽  
Diffusion Coefficient ◽  
Ammonium Chloride ◽  
Polarographic Determination ◽  
Reduction Wave ◽  
Soluble Complex ◽  
Reversible Process ◽  
Complex Species ◽  
Polarographic Wave

The polarography of alizarin alone, and alizarin in the presence of magnesium, has been studied in an ammonia–ammonium chloride electrolyte. Alizarin was found to give a reduction wave with E1/2 = −(0.14 + 0.059 pH) volts vs. S.C.E. and a polarographic diffusion coefficient D, equal to 1.20 × 10−6 cm2 sec−1 over a range of pH from 7.4 to 10.0 in aqueous solution at 25 °C. The slope of the wave corresponded to a two-electron reversible process. The addition of magnesium caused a decrease in the polarographic wave for alizarin, but the combining ratio of magnesium to alizarin was a function of pH, ranging from 1.02 at pH 9.0 to 1.28 at pH 10.1. The combining ratio greater than unity could be attributed to alizarin adsorbed on a 1:1 (MgAlz) precipitate. The removal of alizarin from the solution was not quantitative in the presence of excess magnesium, and there is evidence of the formation of soluble complex species. The reaction is potentially useful for the indirect polarographic determination of magnesium.

scholarly journals Soluble complex formation of theophylline with aliphatic di- and monoamines in aqueous solution.

1982 ◽  
Vol 30 (3) ◽  
pp. 771-776 ◽  
Author(s):  
JUZIRO NISHIJO ◽  
KUMIKO OHNO ◽  
KEIKO NISHIMURA ◽  
MICHIKO HUKUDA ◽  
HIDEKO ISHIMARU ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Complex Formation ◽  
Soluble Complex

scholarly journals Unconventional Complex Coacervation between Neutral Polymer and Inorganic Polyoxometalate in Aqueous Solution via Direct Water Mediation

2019 ◽  
Vol 52 (21) ◽  
pp. 8275-8284 ◽  
Author(s):  
Benxin Jing ◽  
Manuela Ferreira ◽  
Yunyi Gao ◽  
Christopher Wood ◽  
Ruipeng Li ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Complex Coacervation ◽  
Neutral Polymer

scholarly journals Fluorierung von Platin(IV)amminkomplexen in wäßriger Lösung / Fluorination of Ammine Complexes of Platinum(IV) in Aqueous Solution

1978 ◽  
Vol 33 (12) ◽  
pp. 1561-1562 ◽  
Author(s):  
Jochen Jander ◽  
Hans Otto Mayer
Keyword(s):  
Aqueous Solution ◽  
Main Product ◽  
Soluble Complex ◽  
Ammine Complexes

Abstract Unlike chlorination fluorination of ammine complexes of platinum(IV) in aqueous solution does not lead to haloamido complexes. Instead, the triammine complexes [Pt(NH3)3Cl3]Cl and [Pt(NH3)3(NCl2)2Cl]Cl yield no definite main product, and the tetrammine and pentammine complexes trans-[Pt(NH3)4Cl2]Cl2, [Pt(NH3)4(NCl2)Cl]Cl2, [Pt(NH3)5Cl]Cl3, and [Pt(NH3)5(OH)]Cl3 form the sparingly soluble complex trans -[Pt (NH3)4Cl2](H2F3)2 · 2H2O as the main product.

Structures Formed by Cryoprotective Agents Used in Freezc-Etching

1971 ◽  
Vol 29 ◽  
pp. 448-449
Author(s):  
G. G. Cocks ◽  
C. E. Cluthe
Keyword(s):  
Aqueous Solution ◽  
Polyethylene Oxide ◽  
Liquid Nitrogen Temperature ◽  
Ice Crystals ◽  
Etching Technique ◽  
Structural Constituent ◽  
Cryoprotective Agents ◽  
Quick Freezing ◽  
Freeze Etching ◽  
Fractured Surface

The freeze etching technique is potentially useful for examining dilute solutions or suspensions of macromolecular materials. Quick freezing of aqueous solutions in Freon or propane at or near liquid nitrogen temperature produces relatively large ice crystals and these crystals may damage the structures to be examined. Cryoprotective agents may reduce damage to the specimem, hut their use often results in the formation of a different set of specimem artifacts.In a study of the structure of polyethylene oxide gels glycerol and sucrose were used as cryoprotective agents. The experiments reported here show some of the structures which can appear when these cryoprotective agents are used.Figure 1 shows a fractured surface of a frozen 25% aqueous solution of sucrose. The branches of dendritic ice crystals surrounded hy ice-sucrose eutectic can be seen. When this fractured surface is etched the ice in the dendrites sublimes giving the type of structure shown in Figure 2. The ice-sucrose eutectic etches much more slowly. It is the smooth continuous structural constituent surrounding the branches of the dendrites.

Preparation and characterisation of vanadium pentoxide supported rhodium catalyst

1988 ◽  
Vol 46 ◽  
pp. 946-947
Author(s):  
A. Legrouri
Keyword(s):  
Aqueous Solution ◽  
Thermal Decomposition ◽  
Physicochemical Properties ◽  
Surface Area ◽  
Vanadium Pentoxide ◽  
High Purity ◽  
Gas Adsorption ◽  
Rhodium Catalyst ◽  
Optical Methods ◽  
Reducible Oxides

The industrial importance of metal catalysts supported on reducible oxides has stimulated considerable interest during the last few years. This presentation reports on the study of the physicochemical properties of metallic rhodium supported on vanadium pentoxide (Rh/V2O5). Electron optical methods, in conjunction with other techniques, were used to characterise the catalyst before its use in the hydrogenolysis of butane; a reaction for which Rh metal is known to be among the most active catalysts.V2O5 powder was prepared by thermal decomposition of high purity ammonium metavanadate in air at 400 °C for 2 hours. Previous studies of the microstructure of this compound, by HREM, SEM and gas adsorption, showed it to be non— porous with a very low surface area of 6m2/g3. The metal loading of the catalyst used was lwt%Rh on V2Q5. It was prepared by wet impregnating the support with an aqueous solution of RhCI3.3H2O.

TEM observation of iron oxide pillars in montmorillonite

1990 ◽  
Vol 48 (4) ◽  
pp. 882-883
Author(s):  
H. Mori ◽  
Y. Murata ◽  
H. Yoneyama ◽  
H. Fujita
Keyword(s):  
Aqueous Solution ◽  
Iron Oxide ◽  
Fine Particles ◽  
Aqueous Suspension ◽  
Volume Ratio ◽  
Exchange Capacity ◽  
Nano Composites ◽  
Pillared Montmorillonite ◽  
Topographic Features ◽  
Transmission Electron

Recently, a new sort of nano-composites has been prepared by incorporating such fine particles as metal oxide microcrystallites and organic polymers into the interlayer space of montmorillonite. Owing to their extremely large specific surface area, the nano-composites are finding wide application[1∼3]. However, the topographic features of the microstructures have not been elucidated as yet In the present work, the microstructures of iron oxide-pillared montmorillonite have been investigated by high-resolution transmission electron microscopy.Iron oxide-pillared montmorillonite was prepared through the procedure essentially the same as that reported by Yamanaka et al. Firstly, 0.125 M aqueous solution of trinuclear acetato-hydroxo iron(III) nitrate, [Fe3(OCOCH3)7 OH.2H2O]NO3, was prepared and then the solution was mixed with an aqueous suspension of 1 wt% clay by continuously stirring at 308 K. The final volume ratio of the latter aqueous solution to the former was 0.4. The clay used was sodium montmorillonite (Kunimine Industrial Co.), having a cation exchange capacity of 100 mequiv/100g. The montmorillonite in the mixed suspension was then centrifuged, followed by washing with deionized water. The washed samples were spread on glass plates, air dried, and then annealed at 673 K for 72 ks in air. The resultant film products were approximately 20 μm in thickness and brown in color.

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