Reappearance of slow mode in mixtures of polyethylene glycol and poly(sodium methacrylate)

Soft Matter ◽  
2018 ◽  
Vol 14 (24) ◽  
pp. 5039-5047
Author(s):  
Ksenija Kogej ◽  
Jaka Štirn ◽  
Jurij Reščič

After addition of poly(ethylene glycol) to a solution of poly(sodium methacrylate), the slow-mode dynamic light scattering signal reappears.

Soft Matter ◽  
2019 ◽  
Vol 15 (12) ◽  
pp. 2666-2676 ◽  
Author(s):  
Martha Koziol ◽  
Karl Fischer ◽  
Sebastian Seiffert

The low-frequency plateau often found in the rheological spectra of semidilute polymer solutions is shown to be an artifact due to imprecise phase-angle determination; furthermore, the slow mode in the dynamic light scattering autocorrelation function of such solutions is shown to result from minor fractions of 20–200 nm sized impurities.


Polimery ◽  
2021 ◽  
Vol 66 (9) ◽  
pp. 451-458
Author(s):  
Nur Fathin Amirah Shafie ◽  
Mohd Yusof Hamzah ◽  
Roshafima Rasit Ali

The influence of 2-(dimethylamino)ethyl methacrylate (DMAEMA) concentration on the temperature sensitivity of nanogels based on N-isopropylacrylamide (NIPAAM), poly(vinylpyrrolidone) (PVP), poly(ethylene glycol) diacrylate (PEGDA) by gamma radiation induced polymerization was investigated. Dynamic light scattering (DLS) and zeta potential measurements were used to characterize the nanogels. Temperature has been found to cause the nanogel particles to swell and shirnkage, allowing controlled dosing of the drug contained in capsules. The developed nanogels are promising materials with great potential for biomedical applications.


1987 ◽  
Vol 244 (1) ◽  
pp. 87-92 ◽  
Author(s):  
A P Dawson ◽  
G Hills ◽  
J G Comerford

1. Guanosine 5′-[gamma-thio]triphosphate (GTP[S]), if added before GTP, blocks both Ca2+ efflux promoted by GTP and the effect of GTP on enhancement of inositol 1,4,5-triphosphate (IP3)-promoted Ca2+ release from preloaded microsomal vesicles. If, however, GTP[S] is added after GTP, it does not reverse the Ca2+ efflux promoted by GTP, nor does it inhibit IP3-promoted Ca2+ release. 2. The effect of GTP in enhancing IP3-promoted Ca2+ release is maintained after washing the microsomal vesicles free of added GTP. After this treatment, enhancement of IP3-promoted Ca2+ efflux can be observed in the absence of poly(ethylene glycol). 3. Electron microscopy shows that during GTP treatment of microsomal vesicles there is rapid production of very large vesicular structures, apparently produced by fusion of smaller vesicles. 4. Light-scattering changes are detectable during the fusion process. 5. Both Ca2+ efflux promoted by GTP and the enhancement of IP3-promoted Ca2+ release seen in the presence of GTP can probably be attributed to GTP-dependent vesicle fusion.


2010 ◽  
Vol 43 (4) ◽  
pp. 737-742 ◽  
Author(s):  
Tereza Skálová ◽  
Jarmila Dušková ◽  
Jindřich Hašek ◽  
Petr Kolenko ◽  
Andrea Štěpánková ◽  
...  

A set of 16 inexpensive and commercially available polymer precipitants were tested for protein crystallization. Eight of them were found suitable: polyethylene glycol dimethyl ether of molecular weight (MW) 500, 1000 and 2000; di[poly(ethylene glycol)] adipate, MW 900; poly(ethylene glycol-ran-propylene glycol), MW 2500 and 12000; poly(acrylic acid) sodium salt, MW 2100; and polyethylene glycol methyl ether methacrylate, MW 1100. Two new crystallization screens, PolyA and PolyB, were formulated using these eight polymers, each containing 96 solutions – four polymers in combination with 24 common salts and buffers, covering pH values from 4.5 to 9.0. The screens were tested on 29 proteins, 21 of which were crystallized. The tests confirmed the applicability of the eight polymers as precipitants for protein crystallization.


Biosensors ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 475
Author(s):  
Xiaoyuan Zhang ◽  
Zhiqiang Su

In this work, ammonia cross-linked 8-armed polyethylene glycol hydrogel material was successfully synthesized and used as a template for synthesizing nanoparticles with fluorescent properties. The 8-armed polyethylene glycol hydrogel template was used to prepare molybdenum disulfide quantum dots (MoS2 QDs). The ammonium tetrathiomolybdate functioned as a molybdenum source and hydrazine hydrate functioned as a reducing agent. The fluorescence properties of the as-prepared MoS2 QDs were investigated. The bursting of fluorescence caused by adding different concentrations of explosive TNT was studied. The study indicated that the synthesized MoS2 QDs can be used for trace TNT detection with a detection limit of 6 nmol/L and a detection range of 16–700 nmol/L. Furthermore, it indicated that the fluorescence-bursting mechanism is static bursting.


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