Features of Lanthanum Extraction by Intergel System Based on Polyacrylic Acid and Poly-2-Methyl-5-Vinylpyridine Hydrogels

2018 ◽  
pp. 171-190
Keyword(s):  
Polyacrylic Acid

Polyacrylic Acid Modified Cerium Oxide Nanoparticles: Synthesis and Characterization as a Peroxidase Mimic for Non-Enzymatic H2O2 Sensor

2020 ◽  
Vol 16 (5) ◽  
pp. 816-828
Author(s):  
Gurdeep Rattu ◽  
Nishtha Khansili ◽  
Prayaga M. Krishna
Keyword(s):  
Hydrogen Peroxide ◽  
Cerium Oxide ◽  
Polyacrylic Acid ◽  
Spectroscopic Analysis ◽  
Cerium Oxide Nanoparticles ◽  
Oxide Nanoparticles ◽  
Peroxidase Mimic ◽  
Ft Ir ◽  
H2o2 Sensing ◽  
Fluorescence Spectrometer

Background: Cerium oxide nanoparticles (nanoceria) are efficient free-radical scavengers due to their dual valence state and thus exhibit optical and catalytic properties. Therefore, the main purpose of this work was to understand the peroxidase mimic activity of polymer-stabilized nanoceria for enzyme-less H2O2 sensing by fluorescence spectrometer. Objective: This research revealed the development of fluorescence hydrogen peroxide nanosensor based on the peroxidase-like activity of polyacrylic acid stabilized nanoceria (PAA-CeO2 Nps). Methods: PAA-CeO2 Nps were synthesized by simple cross-linking reaction at a low temperature and characterized by XRD, SEM, Zeta potential, TGA, FT-IR and UV-VIS spectroscopic analysis. H2O2 sensing was performed by a fluorescence spectrometer. Results:: The synthesized polymer nanocomposite was characterized by XRD, SEM, TGA, FT-IR and UV-VIS spectroscopic analysis. The XRD diffraction patterns confirmed the polycrystalline nature and SEM micrograph showed nanoparticles having hexagonal symmetry and crystallite size of 32 nm. The broad peak of Ce–O bond appeared at 508 cm-1. UV-VIS measurements revealed a welldefined absorbance peak around 315 nm and an optical band-gap of 3.17 eV. As synthesized PAACeO2 Nps effectively catalysed the decomposition of hydrogen peroxide (H2O2) into hydroxyl radicals. Then terephthalic acid was oxidized by hydroxyl radical to form a highly fluorescent product. Under optimized conditions, the linear range for determination of hydrogen peroxide was 0.01 - 0.2 mM with a limit of detection (LOD) of 1.2 μM. Conclusion: The proposed method is ideally suited for the sensing of H2O2 at a low cost and this detection system enabled the sensing of analytes (sugars), which can enzymatically generate hydrogen peroxide.

scholarly journals Prevention of Postprandial Hyperglycemia by Ophthalmic Nanoparticles Based on Protamine Zinc Insulin in the Rabbit

Pharmaceutics ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 375
Author(s):  
Saori Deguchi ◽  
Fumihiko Ogata ◽  
Takumi Isaka ◽  
Hiroko Otake ◽  
Yosuke Nakazawa ◽  
...  
Keyword(s):  
Blood Glucose ◽  
Plasma Glucose ◽  
Polyacrylic Acid ◽  
Rabbit Model ◽  
Postprandial Hyperglycemia ◽  
Postprandial Blood Glucose ◽  
Oral Glucose ◽  
Glucose Levels ◽  
Protamine Zinc Insulin ◽  
Bead Mill

Postprandial hyperglycemia, a so-called blood glucose spike, is associated with enhanced risks of diabetes mellitus (DM) and its complications. In this study, we attempted to design nanoparticles (NPs) of protamine zinc insulin (PZI) by the bead mill method, and prepare ophthalmic formulations based on the PZI-NPs with (nPZI/P) or without polyacrylic acid (nPZI). In addition, we investigated whether the instillation of the newly developed nPZI and nPZI/P can prevent postprandial hyperglycemia in a rabbit model involving the oral glucose tolerance test (OGTT). The particle size of PZI was decreased by the bead mill to a range for both nPZI and nPZI/P of 80–550 nm with no observable aggregation for 6 d. Neither nPZI nor nPZI/P caused any noticeable corneal toxicity. The plasma INS levels in rabbits instilled with nPZI were significantly higher than in rabbits instilled with INS suspensions (commercially available formulations, CA-INS), and the plasma INS levels were further enhanced with the amount of polyacrylic acid in the nPZI/P. In addition, the rapid rise in plasma glucose levels in OGTT-treated rabbits was prevented by a single instillation of nPZI/P, which was significantly more effective at attenuating postprandial hyperglycemia (blood glucose spike) in comparison with nPZI. In conclusion, we designed nPZI/P, and show that a single instillation before OGTT attenuates the rapid enhancement of plasma glucose levels. These findings suggest a better management strategy for the postprandial blood glucose spike, which is an important target of DM therapy.

scholarly journals The Singular Molecular Conformation of Humic Acids in Solution Influences Their Ability to Enhance Root Hydraulic Conductivity and Plant Growth

Molecules ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 3
Author(s):  
Maite Olaetxea ◽  
Veronica Mora ◽  
Roberto Baigorri ◽  
Angel M. Zamarreño ◽  
Jose M. García-Mina
Keyword(s):  
Polyethylene Glycol ◽  
Humic Acid ◽  
Hydraulic Conductivity ◽  
Plant Growth ◽  
Polyacrylic Acid ◽  
Molecular Conformation ◽  
Water Solution ◽  
Biological Effects ◽  
Root Hydraulic Conductivity ◽  
Molecular Systems

Some studies have reported that the capacity of humic substances to improve plant growth is dependent on their ability to increase root hydraulic conductivity. It was proposed that this effect is directly related to the structural conformation in solution of these substances. To study this hypothesis, the effects on root hydraulic conductivity and growth of cucumber plants of a sedimentary humic acid and two polymers—polyacrylic acid and polyethylene glycol—presenting a molecular conformation in water solution different from that of the humic acid have been studied. The results show that whereas the humic acid caused an increase in root hydraulic conductivity and plant growth, both the polyacrylic acid and the polyethylene glycol did not modify plant growth and caused a decrease in root hydraulic conductivity. These results can be explained by the different molecular conformation in water solution of the three molecular systems. The relationships between these biological effects and the molecular conformation of the three molecular systems in water solution are discussed.

scholarly journals Additive manufacturing of thin electrolyte layers via inkjet printing of highly-stable ceramic inks

2021 ◽  
Author(s):  
Zhongqi Zhu ◽  
Zhiyuan Gong ◽  
Piao Qu ◽  
Ziyong Li ◽  
Sefiu Abolaji Rasaki ◽  
...  
Keyword(s):  
Inkjet Printing ◽  
Polyacrylic Acid ◽  
Storage Period ◽  
Structural Quality ◽  
Solid Loading ◽  
Ultrasonic Dispersion ◽  
Promising Alternative ◽  
Printing Process ◽  
High Solid ◽  
High Solid Loading

AbstractInkjet printing is a promising alternative for the fabrication of thin film components for solid oxide fuel cells (SOFCs) due to its contactless, mask free, and controllable printing process. In order to obtain satisfying electrolyte thin layer structures in anode-supported SOFCs, the preparation of suitable electrolyte ceramic inks is a key. At present, such a kind of 8 mol% Y2O3-stabilized ZrO2 (8YSZ) electrolyte ceramic ink with long-term stability and high solid loading (> 15 wt%) seems rare for precise inkjet printing, and a number of characterization and performance aspects of the inks, such as homogeneity, viscosity, and printability, should be studied. In this study, 8YSZ ceramic inks of varied compositions were developed for inkjet printing of SOFC ceramic electrolyte layers. The dispersing effect of two types of dispersants, i.e., polyacrylic acid ammonium (PAANH4) and polyacrylic acid (PAA), were compared. The results show that ultrasonic dispersion treatment can help effectively disperse the ceramic particles in the inks. PAANH4 has a better dispersion effect for the inks developed in this study. The inks show excellent printable performance in the actual printing process. The stability of the ink can be maintained for a storage period of over 30 days with the help of initial ultrasonic dispersion. Finally, micron-size thin 8YSZ electrolyte films were successfully fabricated through inkjet printing and sintering, based on the as-developed high solid loading 8YSZ inks (20 wt%). The films show fully dense and intact structural morphology and smooth interfacial bonding, offering an improved structural quality of electrolyte for enhanced SOFC performance.

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