scholarly journals Increasing the stability of Lumbricus terrestris erythrocruorin via poly(acrylic acid) conjugation

2018 ◽  
Vol 46 (sup2) ◽  
pp. 1137-1144 ◽  
Author(s):  
Kyle Spivack ◽  
Matthew Tucker ◽  
Devon Zimmerman ◽  
Matthew Nicholas ◽  
Osheiza Abdulmalik ◽  
...  
Keyword(s):  
Acrylic Acid ◽  
Lumbricus Terrestris ◽  
The Stability ◽  
Poly Acrylic Acid

scholarly journals Formation and Stability of Smooth Thin Films with Soft Microgels Made of Poly(N-Isopropylacrylamide) and Poly(Acrylic Acid)

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2638
Author(s):  
Elena Buratti ◽  
Ilaria Sanzari ◽  
Franco Dinelli ◽  
Themistoklis Prodromakis ◽  
Monica Bertoldo
Keyword(s):  
Acrylic Acid ◽  
Colloidal Particles ◽  
Polymer Network ◽  
Spin Speed ◽  
Glass Substrates ◽  
Smooth Film ◽  
The Difference ◽  
The Stability ◽  
Individual Particles ◽  
Poly Acrylic Acid

In this work, soft microgels of Poly(N-Isopropylacrylamide) (PNIPAm) at two different sizes and of interpenetrated polymer network (IPN) composed of PNIPAm and Poly(Acrylic Acid) (PAAc) were synthesized. Then, solutions of these different types of microgels have been spin-coated on glass substrates with different degrees of hydrophobicity. PNIPAm particles with a larger diameter form either patches or a continuous layer, where individual particles are still distinct, depending on the dispersion concentration and spin speed. On the other, PNIPAm particles with a smaller diameter and IPN particles form a continuous and smooth film, with a thickness depending on the dispersion concentration and spin-speed. The difference in morphology observed can be explained if one considers that the microgels may behave as colloidal particles or macromolecules, depending on their size and composition. Additionally, the microgel size and composition can also affect the stability of the depositions when rinsed in water. In particular, we find that the smooth and continuous films show a stimuli-dependent stability on parameters such as temperature and pH, while large particle layers are stable under any condition except on hydrophilic glass by washing at 50 °C.

scholarly journals Effects Of Environmental Factors On The Dispersion Behavior Of Iron Oxide In Aqueous Solutions With Poly Acrylic Acid

2015 ◽  
Vol 60 (2) ◽  
pp. 1561-1564
Author(s):  
E.-H. Lee ◽  
K.-M. Kim ◽  
W.-Y. Maeng ◽  
D.-H. Hur
Keyword(s):  
Molecular Weight ◽  
Acrylic Acid ◽  
High Molecular Weight ◽  
Low Molecular Weight ◽  
Solution Ph ◽  
Molecular Weights ◽  
Aqueous Suspensions ◽  
Magnetite Particles ◽  
The Stability ◽  
Poly Acrylic Acid

Abstract After preparing aqueous suspensions from magnetite particles with a poly-acrylic acid, we investigated the effects of several experimental parameters. We characterized the stability of the suspensions using visual inspection, sedimentation, adsorption, and thermal stability of the dispersant. The dispersion stability is affected by the solution pH, the concentrations of magnetite particles, the molecular weight, the concentration of the dispersants, and the temperature. The stability of the suspensions increased as the concentration of the dispersant and the temperature increased. In terms of the molecular weights of the dispersant, the suspensions with dispersant of low-molecular weight (1800) were more stable than those of high-molecular weight (250000) at room temperature. However, at high temperature the suspensions with high-molecular weight showed stability. The adsorption efficiency of the dispersant was very low. The dispersant of high-molecular weight showed a higher thermal integrity than that of low-molecular weight. From this work, we obtained the optimum conditions for stable aqueous suspensions of magnetite particles.

scholarly journals Comparison of stability properties of poly(acrylic acid) adsorbed on the surface of silica, alumina and mixed silica-alumina nanoparticles — application of turbidimetry method

2014 ◽  
Vol 12 (4) ◽  
pp. 476-479 ◽  
Author(s):  
Małgorzata Wiśniewska ◽  
Teresa Urban ◽  
Agnieszka Nosal-Wiercińska ◽  
Vladimir Zarko ◽  
Vladimir Gun’ko
Keyword(s):  
Acrylic Acid ◽  
Colloidal Suspensions ◽  
Alumina Nanoparticles ◽  
Solution Ph ◽  
Ph Values ◽  
Silica Alumina ◽  
Effective Stabilizer ◽  
The Stability ◽  
Over Time ◽  
Poly Acrylic Acid

AbstractThe influence of anionic poly(acrylic acid) — PAA addition on the stability of synthesized silica, alumina and mixed silica-alumina suspensions as a function of solution pH was studied. The turbidimetry method was used to monitor the changes of the examined systems stability over time. The calculated stability coefficients enabled estimation of polymer adsorption influence on stability of metal oxide suspension. It was shown that the alumina suspension without the polymer is the most unstable at the pH values 6 and 9, whereas the silica polymer was most unstable at pH 3. PAA with higher molecular weight (240 000) is a relatively effective stabilizer of all investigated adsorbents (except silica at pH 3). These properties of poly(acrylic acid) are highly desirable in many branches of industry (e.g. production of cosmetics, pharmaceuticals, paints) where polymers are widely used as effective stabilizers of colloidal suspensions.

scholarly journals Effect of Grafted Hydroquinone on the Acid-Base Properties of Poly(acrylic acid) in the Presence of Copper (II)

2015 ◽  
Vol 2015 ◽  
pp. 1-7
Author(s):  
Nabila Bensacia ◽  
Saâd Moulay ◽  
François Garin ◽  
Ioana Fechete ◽  
Anne Boos
Keyword(s):  
Acrylic Acid ◽  
Coordination Number ◽  
Potentiometric Titration ◽  
Stability Constants ◽  
Acid Base ◽  
Polymer Complexes ◽  
Ionic Environment ◽  
The Stability ◽  
Hasselbalch Equation ◽  
Poly Acrylic Acid

Potentiometric titration of poly(acrylic acid) and hydroquinone-functionalized poly(acrylic acid) was conducted in the presence of copper (II). The effects of hydroquinone functionalizing and copper (II) complexing on the potentiometric titration of poly(acrylic acid) were studied in an ionic environment and in its absence. Henderson-Hasselbalch equation was applied to assess its validity for this titration. Coordination number and the stability constants of the copper- (II-)complexed polymers were determined, and results showed the formation of mostly monodentate and bidentate copper- (II-)polymer complexes.

Protein Polymer Conjugates: Improving the Stability of Hemoglobin with Poly(acrylic acid)

Langmuir ◽  
2011 ◽  
Vol 27 (12) ◽  
pp. 7663-7671 ◽  
Author(s):  
Vindya Thilakarathne ◽  
Victoria A. Briand ◽  
Yuxiang Zhou ◽  
Rajeswari M. Kasi ◽  
Challa V. Kumar
Keyword(s):  
Acrylic Acid ◽  
Polymer Conjugates ◽  
Protein Polymer ◽  
The Stability ◽  
Poly Acrylic Acid

Potentiometric study of cadmium(II) and lead(II) complexation by a cross-linked poly(acrylic acid). Comparison with the linear analogue

2000 ◽  
Vol 78 (12) ◽  
pp. 1637-1641 ◽  
Author(s):  
Catherine Morlay ◽  
Yolande Mouginot ◽  
Monique Cromer ◽  
Michelle Chatelut ◽  
Olivier Vittori
Keyword(s):  
Aqueous Solution ◽  
Acrylic Acid ◽  
Complex Species ◽  
Potentiometric Study ◽  
Predominant Species ◽  
Dilute Aqueous Solution ◽  
Complexing Properties ◽  
The Stability ◽  
Acid Comparison ◽  
Poly Acrylic Acid

Cadmium(II) or lead(II) complex formation with an insoluble cross-linked poly(acrylic acid) was investigated in dilute aqueous solution (NaNO3 0.1 M, 25°C). Potentiometric titrations were carried out to determine the stability constants of the MA and MA2 complex species formed. The Bjerrum's method, modified by Gregor et al. (1955), for the study of polymeric acids was used. The results obtained showed that lead(II) was more readily bound to the polymer. PbA2 was the predominant species; the global stability constant log B102 was equal to 7.4. With cadmium(II), none of the complex species MA or MA2 was predominant (log B102 = 6.0). Finally, the comparison of these results with those of our previous studies showed that the insoluble cross-linked poly(acrylic acid) and its hydrosoluble linear analogues present similar complexing properties towards cadmium(II), lead(II), copper(II), and nickel(II).Key words: insoluble cross-linked poly(acrylic acid), cadmium(II), lead(II), complexation, potentiometry.

Soft ionic liquid based resistive memory characteristics in a two terminal discrete polydimethylsiloxane cylindrical microchannel

2020 ◽  
Vol 8 (38) ◽  
pp. 13368-13374
Author(s):  
Muhammad Umair Khan ◽  
Gul Hassan ◽  
Jinho Bae
Keyword(s):  
Ionic Liquid ◽  
Acrylic Acid ◽  
Sodium Hydroxide ◽  
Sodium Salt ◽  
Resistive Memory ◽  
Cylindrical Microchannel ◽  
Memory Characteristics ◽  
Poly Acrylic Acid

This paper proposes a novel soft ionic liquid (IL) electrically functional device that displays resistive memory characteristics using poly(acrylic acid) partial sodium salt (PAA-Na+:H2O) solution gel and sodium hydroxide (NaOH) in a thin polydimethylsiloxane (PDMS) cylindrical microchannel.

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