Anomalous phase behavior of water-soluble polyelectrolyte and oppositely charged surfactants

1999 ◽  
Vol 277 (12) ◽  
pp. 1117-1124 ◽  
Author(s):  
Y. Yamaguchi ◽  
Y. Inaba ◽  
H. Uchiyama ◽  
H. Kunieda
Keyword(s):  
Phase Behavior ◽  
Water Soluble ◽  
Oppositely Charged

scholarly journals Solubilization of Charged Porphyrins in Interpolyelectrolyte Complexes: A Computer Study

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 502
Author(s):  
Karel Šindelka ◽  
Zuzana Limpouchová ◽  
Karel Procházka
Keyword(s):  
Dissipative Particle Dynamics ◽  
Water Soluble ◽  
Coarse Grained ◽  
Core Shell ◽  
Computer Study ◽  
Interpolyelectrolyte Complex ◽  
The Core ◽  
Porphyrin Derivatives ◽  
Oppositely Charged ◽  
Positively Charged

Using coarse-grained dissipative particle dynamics (DPD) with explicit electrostatics, we performed (i) an extensive series of simulations of the electrostatic co-assembly of asymmetric oppositely charged copolymers composed of one (either positively or negatively charged) polyelectrolyte (PE) block A and one water-soluble block B and (ii) studied the solubilization of positively charged porphyrin derivatives (P+) in the interpolyelectrolyte complex (IPEC) cores of co-assembled nanoparticles. We studied the stoichiometric mixtures of 137 A10+B25 and 137 A10−B25 chains with moderately hydrophobic A blocks (DPD interaction parameter aAS=35) and hydrophilic B blocks (aBS=25) with 10 to 120 P+ added (aPS=39). The P+ interactions with other components were set to match literature information on their limited solubility and aggregation behavior. The study shows that the moderately soluble P+ molecules easily solubilize in IPEC cores, where they partly replace PE+ and electrostatically crosslink PE− blocks. As the large P+ rings are apt to aggregate, P+ molecules aggregate in IPEC cores. The aggregation, which starts at very low loadings, is promoted by increasing the number of P+ in the mixture. The positively charged copolymers repelled from the central part of IPEC core partially concentrate at the core-shell interface and partially escape into bulk solvent depending on the amount of P+ in the mixture and on their association number, AS. If AS is lower than the ensemble average ⟨AS⟩n, the copolymer chains released from IPEC preferentially concentrate at the core-shell interface, thus increasing AS, which approaches ⟨AS⟩n. If AS>⟨AS⟩n, they escape into the bulk solvent.

scholarly journals Phase behavior of mixtures of oppositely charged protein nanoparticles at asymmetric charge ratios

2006 ◽  
Vol 73 (4) ◽  
Author(s):  
P. Maarten Biesheuvel ◽  
Saskia Lindhoud ◽  
Martien A. Cohen Stuart ◽  
Renko de Vries
Keyword(s):  
Phase Behavior ◽  
Protein Nanoparticles ◽  
Oppositely Charged

scholarly journals Hygroscopic behavior of atmospheric aerosols containing nitrates and water-soluble organic acids

2017 ◽  
Author(s):  
Bo Jing ◽  
Zhen Wang ◽  
Fang Tan ◽  
Yucong Guo ◽  
Shengrui Tong ◽  
...  
Keyword(s):  
Organic Acids ◽  
Organic Acid ◽  
Phase Behavior ◽  
Water Uptake ◽  
Sodium Nitrate ◽  
Atmospheric Aerosols ◽  
Water Soluble ◽  
Atmospheric Environment ◽  
Mass Transfer Limitation ◽  
Continuous Growth

Abstract. While nitrates have critical impacts on environmental effects of atmospheric aerosols, the effects of coexisting species on hygroscopicity of nitrates remain uncertain. The hygroscopic behaviors of nitrate aerosols (NH4NO3, NaNO3, Ca(NO3)2) and their internal mixtures with water soluble organic acids at varying mass ratios were determined using a hygroscopicity tandem differential mobility analyzer (HTDMA). The nitrate/organic acid mixed aerosols exhibit varying phase behavior and hygroscopic growth depending upon the type of components in the particles. Whereas pure nitrate particles show continuous water uptake with increasing RH, the deliquescence transition is still observed for ammonium nitrate particles internally mixed with organic acids such as oxalic acid and succinic acid with a high deliquescence point. The hygroscopicity of submicron aerosols containing sodium nitrate and an organic acid is also characterized by continuous growth, indicating that sodium nitrate tends to exist in a liquid-like state under dry conditions. It is observed that in contrast to the pure components the water uptake is hindered at low and moderate RH for calcium nitrate particles containing malonic acid or phthalic acid, suggesting the potential effects of mass transfer limitation in highly viscous mixed systems. Our findings improve fundamental understanding of the phase behavior and water uptake of nitrate-containing aerosols in the atmospheric environment.

scholarly journals Nanoparticle-Doped Hybrid Polyelectrolyte Microcapsules with Controlled Photoluminescence for Potential Bioimaging Applications

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4076
Author(s):  
Galina Nifontova ◽  
Victor Krivenkov ◽  
Mariya Zvaigzne ◽  
Anton Efimov ◽  
Evgeny Korostylev ◽  
...  
Keyword(s):  
Semiconductor Nanocrystals ◽  
Emission Spectra ◽  
Fluorescent Imaging ◽  
Water Soluble ◽  
Layer By Layer ◽  
Layer Deposition ◽  
Theranostic Agents ◽  
Further Development ◽  
Oppositely Charged ◽  
Transformation Processes

Fluorescent imaging is widely used in the diagnosis and tracking of the distribution, interaction, and transformation processes at molecular, cellular, and tissue levels. To be detectable, delivery systems should exhibit a strong and bright fluorescence. Quantum dots (QDs) are highly photostable fluorescent semiconductor nanocrystals with wide absorption spectra and narrow, size-tunable emission spectra, which make them suitable fluorescent nanolabels to be embedded into microparticles used as bioimaging and theranostic agents. The layer-by-layer deposition approach allows the entrapping of QDs, resulting in bright fluorescent microcapsules with tunable surface charge, size, rigidity, and functional properties. Here, we report on the engineering and validation of the structural and photoluminescent characteristics of nanoparticle-doped hybrid microcapsules assembled by the deposition of alternating oppositely charged polyelectrolytes, water-soluble PEGylated core/shell QDs with a cadmium selenide core and a zinc sulfide shell (CdSe/ZnS), and carboxylated magnetic nanoparticles (MNPs) onto calcium carbonate microtemplates. The results demonstrate the efficiency of the layer-by-layer approach to designing QD-, MNP-doped microcapsules with controlled photoluminescence properties, and pave the way for the further development of next-generation bioimaging agents based on hybrid materials for continuous fluorescence imaging.

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