Synthesis of water-soluble luminescent poly(acrylic acid)-encapsulated CdTe/CdS nanoparticles

2014 ◽  
Vol 92 (1) ◽  
pp. 54-57 ◽  
Author(s):  
Jane Betty Goh ◽  
Richard W. Loo ◽  
M. Cynthia Goh
Keyword(s):  
Acrylic Acid ◽  
Quantum Dot ◽  
Water Soluble ◽  
Cds Nanoparticles ◽  
Ambient Conditions ◽  
Poly Acrylic Acid

Described is the synthesis in water under ambient conditions of water-soluble, luminescent poly(acrylic acid)-encapsulated CdTe/CdS nanoparticles. Counterion-collapsed poly(acrylic acid) is used as a nanotemplate for the formation of the quantum dot core. Gram quantities of nanoparticles are easily obtained. Simply varying the amount of thioacetamide used in the synthesis can shift the emission wavelengths of the resulting nanoparticles from green to yellow to red.

scholarly journals Antibacterial activity of chitosan and the interpolyelectrolyte complexes of poly(acrylic acid)-chitosan

2010 ◽  
Vol 53 (3) ◽  
pp. 623-628 ◽  
Author(s):  
Hortensia Ortega-Ortiz ◽  
Baltazar Gutiérrez-Rodríguez ◽  
Gregorio Cadenas-Pliego ◽  
Luis Ibarra Jimenez
Keyword(s):  
Antibacterial Activity ◽  
Acrylic Acid ◽  
Antimicrobial Agents ◽  
Water Soluble ◽  
Amino Groups ◽  
Molecular Weights ◽  
Carboxylic Acid Groups ◽  
Microbial Inhibition ◽  
Interpolyelectrolyte Complexes ◽  
Poly Acrylic Acid

The antimicrobial activity of chitosan and water soluble interpolyelectrolyte complexes of poly(acrylic acid)-chitosan was studied. Chitosans of two different molecular weights were tested at different concentration for 0.5 to 5 g·L-1 as antimicrobial agents against P. aeruginosa and P. oleovorans. In both cases, the best microbial inhibition was obtained with the concentration of 5 g·L-1. However, the interpolyelectrolyte complexes of poly(acrylic acid)-chitosan with composition φ =2 produced higher antibacterial activity than the two chitosans at the concentration of 0.5 g·L-1. The NPEC2 complex was more effective than chitosans. This could be attributed to the number of moles of the amino groups of chitosan and the carboxylic acid groups of the interpolyelectrolyte complexes poly(acrylic acid).

Water-Soluble Poly(2-cinnamoylethyl methacrylate)-block-poly(acrylic acid) Nanospheres as Traps for Perylene

Langmuir ◽  
1998 ◽  
Vol 14 (7) ◽  
pp. 1554-1559 ◽  
Author(s):  
Guochang Wang ◽  
Fred Henselwood ◽  
Guojun Liu
Keyword(s):  
Acrylic Acid ◽  
Water Soluble ◽  
Soluble Poly ◽  
Poly Acrylic Acid

Poly(acrylamide-co-acrylic acid) gel polymer electrolyte incorporating with water-soluble sodium sulfide salt for quasi-solid-state quantum dot-sensitized solar cell

2020 ◽  
Vol 32 (2) ◽  
pp. 183-191
Author(s):  
YC Lee ◽  
MH Buraidah ◽  
HJ Woo
Keyword(s):  
Ionic Conductivity ◽  
Acrylic Acid ◽  
Quantum Dot ◽  
Polymer Electrolyte ◽  
Sodium Sulfide ◽  
Ethylene Carbonate ◽  
Gel Polymer Electrolyte ◽  
Liquid Electrolyte ◽  
Water Soluble ◽  
Poly Acrylamide

Rapid decay of photoanode, leakage from sealant, and evaporation of electrolyte are always the major concerns of quantum dot-sensitized solar cells (QDSCs) based on liquid electrolyte. Subsequently, gel polymer electrolyte (GPE) appears as an attractive solution in addition to lower cost, lighter weight, and flexibility. Poly(acrylamide- co-acrylic acid) (PAAm-PAA) is of special interest to act as a polymer host to entrap liquid electrolyte because it provides high transparency, good gelatinizing properties, and excellent compatibility with the liquid electrolyte. In this work, the electrical and transport properties of PAAm-PAA GPE incorporating with water-soluble sodium sulfide were characterized by impedance spectroscopy. An increment of ionic conductivity was observed with the incorporation of ethylene carbonate (EC) and potassium chloride (KCl). The highest room temperature ionic conductivity of PAAm-PAA GPE is 70.82 mS·cm−1. QDSC based on PAAm-PAA GPE with the composition of 1.3 wt% of KCl, 0.9 wt% of EC, 55.3 wt% of PAAm-PAA, 38.5 wt% of sodium sulfide, and 4.0 wt% of sulfur can present up to 1.80% of light-to-electricity conversion efficiency.

Shear-induced changes in chain configuration of poly(acrylic acid) in dilute solution

1989 ◽  
Vol 47 ◽  
pp. 698-699
Author(s):  
J.P. Armistead ◽  
R.R. Price ◽  
O.-K. Kim ◽  
L.-S. Choi
Keyword(s):  
Acrylic Acid ◽  
Shear Flow ◽  
Drag Reduction ◽  
Fluorescence Probe ◽  
Water Soluble ◽  
Polymer Chains ◽  
Rotating Disc ◽  
Molecular Configuration ◽  
Flexible Polymer ◽  
Poly Acrylic Acid

Small amounts (less than 30 ppm) of polymer dissolved in solution may significantly reduce the work required to pump fluids through a pipe at a given rate. In other words, the drag of the solution along the pipe walls is reduced. Drag reduction by polymers has been well characterized, however the molecular origin of the phenomena is not fully understood. Polymers that exhibit drag reduction characteristics typically have high molecular weight, have predominantly linear, flexible chains, and have an expanded molecular configuration in solution.Work in this laboratory has focused on the drag reduction behavior of poly(acrylic acid), PAA, in recent years. This polymer is one of the most shear stable water-soluble polymers and due to the ionic groups in the polymer chain its conformation in solution changes with pH and ionic strength. In a recent work, PAA solutions of 18 ppm, pH=8.1, showed an initial drag reduction of over thirty-five percent in rotating disc experiments. Over four minutes of shearing the drag reduction decreased to ten percent. This was surprising because of the known shear stability of PAA. When the sheared solution was left undisturbed for two weeks, it did not recover its drag reduction performance. However, the addition of NaCl to the solution during the shearing immediately restored drag reduction to its initial level. It was hypothesized that the shear flow induced interchain association that was possibly stabilized by hydrogen bonding and that the addition of the NaCl caused dissociation and drag reduction recovery. In additional work, fluorescence probe studies showed that shear flow induced local chain rigidity in the originally flexible polymer chains. In this study, the drag reduction experiments were repeated and the configurations of the sheared and unsheared polymer chains were viewed using electron microscopy.

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