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.

Immobilization of urease in poly(1-vinyl imidazole)/poly(acrylic acid) network

2010 ◽  
Vol 64 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Mehmet Şenel ◽  
Agah Coşkun ◽  
M. Fatih Abasıyanık ◽  
Ayhan Bozkurt
Keyword(s):  
Acrylic Acid ◽  
Enzyme Immobilization ◽  
Storage Stability ◽  
Polymer Network ◽  
Ft Ir ◽  
Basic Characteristics ◽  
And Storage ◽  
Menten Constant ◽  
Ft Ir Spectroscopy ◽  
Poly Acrylic Acid

AbstractIn this study, urease was immobilized in a polymer network obtained by complexation of poly(1-vinyl imidazole) (PVI) with poly(acrylic acid) (PAA). Preparation of the polymer network was monitored by FT-IR spectroscopy. Scanning electron microscopy (SEM) revealed that enzyme immobilization had a strong effect on film morphology. Proton conductivity of the PVI/PAA network was measured via impedance spectroscopy under humidified conditions. Values of the Michaelis-Menten constant (K M) for immobilized urease were higher than for the free enzyme, indicating a decreased affinity of the enzyme to its substrate. The basic characteristics (pHopt, pHstability, T opt, T stability, reusability, and storage stability) of immobilized urease were determined. The results show that the PAA/PVI polymer network is suitable for enzyme immobilization.

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 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

Synthesis and Characteristics of Interpenetrating Polymer Network Hydrogels Based on Konjac Glucomannan with Different Molecular Weights and Poly(acrylic acid)

2011 ◽  
Vol 393-395 ◽  
pp. 1004-1007
Author(s):  
Xue Yao ◽  
Xue Gang Luo ◽  
Ben Chao Han
Keyword(s):  
Acrylic Acid ◽  
Enzymatic Degradation ◽  
Drug Carrier ◽  
Polymer Network ◽  
Konjac Glucomannan ◽  
Interpenetrating Polymer Network ◽  
Swelling Ratio ◽  
Molecular Weights ◽  
Ft Ir ◽  
Poly Acrylic Acid

Konjac glucomannan with different molecular weights/poly(acrylic acid) hydrogels were prepared in this paper. The structure of the IPN hydrogels was characterized by FT-IR and SEM. The swelling ratio of these hydrogels showed they had pH-sensitive properties and the enzymatic degradation tests showed the hydrogels retain the enzymatic degradation character of KGM. Furthermore, hydrogel composed of native KGM degraded sharply in enzymatic degradation test and it had bigger swelling ratio and weight loss ratio than those hydrogels which composed of lower molecular weights KGM. Therefore, hydrogels composed of lower molecular weight might release drug more stable when they were used as drug carrier.

scholarly journals In Situ Nitroxide-Mediated Polymerized Poly(acrylic acid) as a Stabilizer/Compatibilizer Carbon Nanotube/Polymer Composites

2007 ◽  
Vol 2007 ◽  
pp. 1-12 ◽  
Author(s):  
Vitaliy Datsyuk ◽  
Laurent Billon ◽  
Christelle Guerret-Piécourt ◽  
Sylvie Dagréou ◽  
Nicolas Passade-Boupatt ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Acrylic Acid ◽  
Polymer Composites ◽  
Diblock Copolymers ◽  
Polymer Network ◽  
Electron Microscopies ◽  
Transmission Electron ◽  
Wide Range ◽  
Poly Acrylic Acid

Carbon nanotube (CNT) polymer composites were synthesized via in situ nitroxide-mediated diblock copolymerization. Poly(acrylic acid) (PAA) was chosen as a first block to obtain a precomposite CNT-PAA which is readily dispersible in various solvents including water. The immobilization of the stable poly(acrylic acid) alkoxyamine functionality on the nanotube surface occurs during the synthesis of the first block without CNT prior treatment. The living character of this block is established by spectroscopic methods and the nature of the CNT/PAA interaction is discussed. This living first block offers the opportunity to reinitiate the polymerization of a second block that can be chosen among a wide range of monomers. This versatility is illustrated with a second block containing methyl acrylate (MA) or styrene (S). Scanning and transmission electron microscopies confirm good CNT dispersion in the polymer network, while transmission electron microscopy also spots the anchorage locations of PAA on the CNT surface. Such nanotubes wrapped by diblock copolymers can be dispersed in various polymer matrices to create CNT—polymer composites. Conductivity measurements show that these composites obey a percolation-like power law with a low percolation threshold (less than 0.5 vol%) and a high maximum conductivity (up to 1.5 S/cm at room temperature).

Water Behavior of Poly(acrylic acid)/ Poly (acrylonitrile) Semi-Interpenetrating Polymer Network Hydrogels

2004 ◽  
Vol 16 (4) ◽  
pp. 625-635 ◽  
Author(s):  
Seon Jeong Kim ◽  
Ki Jung Lee ◽  
Sang Min Lee ◽  
In Young Kim ◽  
Sun I. Kim
Keyword(s):  
Acrylic Acid ◽  
Polymer Network ◽  
Interpenetrating Polymer Network ◽  
Water Behavior ◽  
Poly Acrylonitrile ◽  
Poly Acrylic Acid
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