scholarly journals Synthesis of polyampholytic diblock copolymers via RAFT aqueous solution polymerization

2021 ◽  
Author(s):  
S. M. North ◽  
S. P. Armes
Keyword(s):  
Aqueous Solution ◽  
Light Scattering ◽  
Nmr Spectroscopy ◽  
Dynamic Light Scattering ◽  
Diblock Copolymers ◽  
Solution Polymerization ◽  
H Nmr ◽  
Aqueous Solution Polymerization ◽  
Solution Behaviour

Two new classes of polyampholytic diblock copolymers are prepared via RAFT aqueous solution polymerization and their aqueous solution behaviour is assessed using 1H NMR spectroscopy, dynamic light scattering and aqueous electrophoresis measurements.

Properties and Synthesis of Kaolin / Potassium Polyacrylate / Acrylamide Composite Superabsorbent Resin

2011 ◽  
Vol 287-290 ◽  
pp. 1331-1334
Author(s):  
Hao Ren ◽  
Jie Li ◽  
Yu Fen Zhang ◽  
Tai Zhong Huang
Keyword(s):  
Aqueous Solution ◽  
Saline Water ◽  
Monomer Concentration ◽  
Water Absorbency ◽  
Solution Polymerization ◽  
Synthetic Resin ◽  
Polymer Molecules ◽  
Aqueous Solution Polymerization ◽  
Crosslinker Concentration ◽  
Superabsorbent Resin

The aqueous solution polymerization methods were used for the synthesis of superabsorbent resin. The effects of different experimental factors on synthetic resin water absorbency were investigated in this paper. The variables examined in this study included monomer concentration, neutralization degree, initiator and crosslinker concentration, reaction temperature and time, etc. The maximum absorbencies of distilled and 0.9% saline water are 919 times and 92 times respectively under optimum condition. Analysis from FTIR and SEM shown the polymer molecules can be firmly fixed with kaolin, the bonding of kaolin and polymer is good in CSR.

Vesicles made of PS-PI cyclic diblock copolymers: In situ freeze-drying cryo-TEM and dynamic light scattering experiments

2005 ◽  
Vol 128 ◽  
pp. 163 ◽  
Author(s):  
Jean-Luc Putaux ◽  
Edson Minatti ◽  
Christelle Lefebvre ◽  
Redouane Borsali ◽  
Michel Schappacher ◽  
...  
Keyword(s):  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Freeze Drying ◽  
Diblock Copolymers

Synthesis and properties of multiheaded and multitailed surfactants based on tripentaerythritol

2015 ◽  
Vol 93 (5) ◽  
pp. 502-508 ◽  
Author(s):  
Nawal K. Paul ◽  
Tyler Mercer ◽  
Hussein Al-Mughaid ◽  
D. Gerrard Marangoni ◽  
Michael J. McAlduff ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Aqueous Solution ◽  
Surface Tension ◽  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Self Assembly ◽  
Alkyl Chain ◽  
Alkyl Chain Length ◽  
Aggregation Behaviour ◽  
Aggregate Structures

The surface and self-assembly properties of a family of multiheaded, multitailed surfactants based on a tripentaerythritol backbone are described. Critical aggregation concentrations of these unusual surfactant systems have been determined from surface tension measurements; aggregate sizes in the presence and absence of a small amount of added electrolyte have been obtained via dynamic light scattering, and the morphologies of the aggregates were examined from electron microscopy measurements. In general, when compared to conventional ionic and two-headed surfactants (and other recently synthesized pentaerythritol derived surfactants from this group), these multiheaded surfactants exhibited some unusual trends in their aggregation behaviour and interesting aggregate structures in aqueous solution, as a function of alkyl chain length.

scholarly journals Temperature Induced Aggregation and Clouding in Humic Acid Solutions

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Leah Shaffer ◽  
Ray von Wandruszka
Keyword(s):  
Aqueous Solution ◽  
Light Scattering ◽  
Humic Acid ◽  
Dynamic Light Scattering ◽  
Acid Solutions ◽  
Inverse Temperature ◽  
Mechanical Agitation ◽  
Coulombic Repulsion ◽  
Polarity Sensitive ◽  
Induced Aggregation

Humic acids in aqueous solution demonstrate inverse temperature-solubility relationships when solution conditions are manipulated to reduce coulombic repulsion among the humic polyanions. These effects were followed by dynamic light scattering (DLS) measurements of the resulting aggregates, as well as the addition of a polarity sensitive fluorescent probe (pyrene). The humic solutions could be primed for temperature induced clouding by carefully lowering the pH to a point where hydration effects became dominant. The exact value of the cloud point (CP) was a function of both pH and humate concentration. The CPs mostly lay in the range 50–90°C, but DLS showed that temperature induced aggregation proceeded from approximately 30°C onward. Similar effects could be achieved by adding multivalent cations at concentrations below those which cause spontaneous precipitation. The declouding of clouded humate solutions could be affected by lowering the temperature combined with mechanical agitation to disentangle the humic polymers.

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