scholarly journals Viscoelastic Properties of Polyelectrolyte Multilayers Swollen with Ionic Liquid Solutions

Polymers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1285 ◽  
Author(s):  
Nagma Parveen ◽  
Pritam Kumar Jana ◽  
Monika Schönhoff
Keyword(s):  
Ionic Liquid ◽  
Hydrophobic Interactions ◽  
Salt Content ◽  
Water Soluble ◽  
Polyelectrolyte Multilayers ◽  
Layer By Layer ◽  
Organic Salts ◽  
Low Salt ◽  
Liquid Solutions ◽  
Voigt Model

Polyelectrolyte multilayers (PEM) obtained by layer-by-layer assembly can be doped with ionic liquid (IL) via the swelling of the films with IL solutions. In order to examine the mechanical properties of IL-containing PEM, we implement a Kelvin-Voigt model to obtain thickness, viscosity and elastic modulus from the frequency and dissipation shifts determined by a dissipative quartz crystal microbalance (QCM-D). We analyze the changes in the modeled thickness and viscoelasticity of PEI(PSS/PADMAC)4PSS and PEI(PSS/PAH)4PSS multilayers upon swelling by increasing the concentration of either 1-Ethyl-3-methylimidazolium chloride or 1-Hexyl-3-methylimidazolium chloride, which are water soluble ILs. The results show that the thickness of the multilayers changes monotonically up to a certain IL concentration, whereas the viscosity and elasticity change in a non-monotonic fashion with an increasing IL concentration. The changes in the modeled parameters can be divided into three concentration regimes of IL, a behavior specific to ILs (organic salts), which does not occur with swelling by simple inorganic salts such as NaCl. The existence of the regimes is attributed to a competition of the hydrophobic interactions of large hydrophobic ions, which enhance the layer stability at a low salt content, with the electrostatic screening, which dominates at a higher salt content and causes a film softening.

scholarly journals Peptide Profiling and Biological Activities of 12-Month Ripened Parmigiano Reggiano Cheese

Biology ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 170 ◽  
Author(s):  
Lisa Solieri ◽  
Andrea Baldaccini ◽  
Serena Martini ◽  
Aldo Bianchi ◽  
Valentina Pizzamiglio ◽  
...  
Keyword(s):  
Bioactive Peptides ◽  
Antioxidant Activities ◽  
Biological Activities ◽  
Salt Content ◽  
Fat Content ◽  
Water Soluble ◽  
Soluble Peptide ◽  
Fat Reduction ◽  
Low Salt ◽  
Parmigiano Reggiano

Proteolysis degree, biological activities, and water-soluble peptide patterns were evaluated in 12 month-ripened Parmigiano Reggiano (PR) cheeses collected in different dairy farms and showing different salt and fat content. Samples classified in high-salt and high-fat group (HH) generally showed lower proteolysis degree than samples having low-salt and low-fat content (LL). This positive correlation between salt/fat reduction and proteolysis was also confirmed by the analysis of biological activities, as the LL group showed higher average values of angiotensin-converting enzyme (ACE)-inhibitory and antioxidant activities. UHPLC/HR-MS allowed the identification of 805 unique peptides: LL and HH groups shared 59.3% of these peptides, while 20.9% and 19.9% were LL and HH specific, respectively. Frequency analysis of peptides identified a core of 183 peptides typical of 12-month ripened PR cheeses (corresponding to the 22.7% of total peptides), but no significant differences were detected in peptide patterns between LL and HH groups. Forty bioactive peptides, including 18 ACE-inhibitors and 12 anti-microbial peptides, were identified, of which 25 firstly found in PR cheese. Globally, this work contributed to unraveling the potentially healthy benefits of peptides fraction in PR cheese and provided prior evidence that PR with reduced fat/salt content showed the highest antihypertensive and antioxidant activities.

Swelling and Stability of Polyelectrolyte Multilayers in Ionic Liquid Solutions

2013 ◽  
Vol 46 (19) ◽  
pp. 7880-7888 ◽  
Author(s):  
Nagma Parveen ◽  
Monika Schönhoff
Keyword(s):  
Ionic Liquid ◽  
Polyelectrolyte Multilayers ◽  
Liquid Solutions

Consumer preferences for low-salt foods - a Danish case study based on a comprehensive supermarket intervention

2021 ◽  
pp. 1-26
Author(s):  
Sigrid Denver ◽  
Tove Christensen ◽  
Jonas Nordström
Keyword(s):  
Consumer Preferences ◽  
Salt Content ◽  
Dietary Advice ◽  
Scanner Data ◽  
Statistical Regression ◽  
Salt Consumption ◽  
Dietary Choices ◽  
Low Salt ◽  
Reduced Salt

Abstract Objective: The objective is to analyze Danish consumers’ attitudes to buying food with reduced salt content. Design: The study is based on a comprehensive store intervention that included 114 stores belonging to the same supermarket chain. Three different salt claims were tested for eight weeks on six test products within the categories bread, cornflakes and frozen pizzas. Scanner data were supplemented with 134 brief interviews with consumers in nine selected stores. Setting: Stores spread across Denmark. Participants: Consumers who buy food in the stores. Results: Statistical regression analyses of the scanner data indicated that none of the three claims significantly affected demand for any of the test products. The interviews confirmed that many consumers were more focused on other elements of the official dietary advice than reduced salt consumption, such as eating plenty of vegetables, choosing products with whole grains and reducing their intake of sugar and fat. Conclusions: Overall, both the scanner data and the interviews pointed in the same direction, toward the conclusion that salt content is often a secondary factor when Danish consumers make dietary choices.

scholarly journals Electrical Field-Assisted Gene Delivery from Polyelectrolyte Multilayers

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 133
Author(s):  
Yu-Che Cheng ◽  
Shu-Lin Guo ◽  
Kun-Da Chung ◽  
Wei-Wen Hu
Keyword(s):  
Gene Delivery ◽  
Electric Field ◽  
Treatment Time ◽  
Transfection Efficiency ◽  
Polyelectrolyte Multilayers ◽  
Aqueous Environment ◽  
Layer By Layer ◽  
Electrical Field ◽  
Lbl Assembly ◽  
Electric Field Treatment

To sustain gene delivery and elongate transgene expression, plasmid DNA and cationic nonviral vectors can be deposited through layer-by-layer (LbL) assembly to form polyelectrolyte multilayers (PEMs). Although these macromolecules can be released for transfection purposes, their entanglement only allows partial delivery. Therefore, how to efficiently deliver immobilized genes from PEMs remains a challenge. In this study, we attempt to facilitate their delivery through the pretreatment of the external electrical field. Multilayers of polyethylenimine (PEI) and DNA were deposited onto conductive polypyrrole (PPy), which were placed in an aqueous environment to examine their release after electric field pretreatment. Only the electric field perpendicular to the substrate with constant voltage efficiently promoted the release of PEI and DNA from PEMs, and the higher potential resulted in the more releases which were enhanced with treatment time. The roughness of PEMs also increased after electric field treatment because the electrical field not only caused electrophoresis of polyelectrolytes and but also allowed electrochemical reaction on the PPy electrode. Finally, the released DNA and PEI were used for transfection. Polyplexes were successfully formed after electric field treatment, and the transfection efficiency was also improved, suggesting that this electric field pretreatment effectively assists gene delivery from PEMs and should be beneficial to regenerative medicine application.

Effect of temperature on the osmotic behavior of LCST type ionic liquid solutions as draw solutions in the forward osmosis process

2021 ◽  
pp. 119164
Author(s):  
Eiji Kamio ◽  
Hiroki Kurisu ◽  
Tomoki Takahashi ◽  
Atsushi Matsuoka ◽  
Tomohisa Yoshioka ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Forward Osmosis ◽  
Effect Of Temperature ◽  
Liquid Solutions ◽  
Osmotic Behavior

Effect of Concentration on the Glass Transition and Viscoelastic Properties of Poly(methyl methacrylate)/Ionic Liquid Solutions

2011 ◽  
Vol 44 (4) ◽  
pp. 1016-1025 ◽  
Author(s):  
Michelle M. Mok ◽  
Xingcheng Liu ◽  
Zhifeng Bai ◽  
Yu Lei ◽  
Timothy P. Lodge
Keyword(s):  
Ionic Liquid ◽  
Glass Transition ◽  
Methyl Methacrylate ◽  
Viscoelastic Properties ◽  
Poly Methyl Methacrylate ◽  
Liquid Solutions

Preparation and morphology of different types of cellulose spherulites from concentrated cellulose ionic liquid solutions

Soft Matter ◽  
2013 ◽  
Vol 9 (11) ◽  
pp. 3013 ◽  
Author(s):  
Hongzan Song ◽  
Yanhua Niu ◽  
Jian Yu ◽  
Jun Zhang ◽  
Zhigang Wang ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Liquid Solutions ◽  
Different Types
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