MESOSCOPIC SIMULATION OF STRUCTURAL TRANSITIONS IN CYSTEINE-SILVER SOLUTION

Выполнено изучение структурных переходов в цистеин-серебряном растворе в зависимости от изменения концентрации соли - инициатора гелеобразования. Расчеты осуществлялись с использованием скорректированной мезоскопической модели, базирующейся на модели «липких сфер». Построена диаграмма состояний системы в координатах концентрация соли - энергия парного взаимодействия кластеров меркаптида серебра. Показано, что скорректированная модель хорошо воспроизводит все структурные превращения в цистеин-серебряном растворе: золь-гель переход, распад гель сетки и выпадения меркаптида серебра в осадок. The study of structural transitions in a cysteine-silver solution was carried out depending on the change in the concentration of the salt - the initiator of gelation. The calculations are carried out using a modified mesoscopic model based on the «sticky spheres» model. A state diagram was constructed in the coordinates - salt concentration, the pair interaction energy of silver mercaptide clusters. It is shown that the modified model reproduces well all structural transformations in a cysteine-silver solution: sol-gel transition, the disintegration of the gel network, and precipitation of silver mercaptide.

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Effects of salts on the sol-gel transition and gel network structure

10.32657/10356/5441 ◽

2005 ◽

Author(s):

Yirong Xu

Keyword(s):

Network Structure ◽

Sol Gel ◽

Sol Gel Transition ◽

Gel Network ◽

Gel Transition

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The fluid gels: A research review

E3S Web of Conferences ◽

10.1051/e3sconf/202021301015 ◽

2020 ◽

Vol 213 ◽

pp. 01015

Author(s):

Ke Zhang

Keyword(s):

Physical Properties ◽

Food Industry ◽

Sol Gel ◽

Research Progress ◽

Research Review ◽

Sol Gel Transition ◽

Food Design ◽

Gel Network ◽

Application Prospects ◽

Gel Transition

Fluid gels were formed during the sol-gel transition of biological polysaccharide, which were damaged by the shear field and fails to form a static gel network, and the resulting suspension of gel particles were also called shear gel. Modern food design usually requires both deliciousness and health. The special physical properties of fluid gels allow foods with reduced sugar and salt to maintain good texture and physical properties, so they are of great significance in modern product design. This article reviewed the preparation and latest research progress of fluid gels. It demonstrated their unique application prospects for the modern food industry.

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USING OF STICKY SPHERE MODEL FOR QUALITATIVE REPRODUCTION OF BASIC PHASE TRANSITIONS OF CYSTEINE-SILVER SOLUTION

Physical and Chemical Aspects of the Study of Clusters Nanostructures and Nanomaterials ◽

10.26456/pcascnn/2020.12.252 ◽

2020 ◽

pp. 252-259

Author(s):

Максим Дмитриевич Малышев ◽

Павел Михайлович Пахомов ◽

Павел Вячеславович Комаров

Keyword(s):

Phase Transitions ◽

Salt Concentration ◽

Software Package ◽

Direct Impact ◽

Sphere Model ◽

Silver Solution ◽

Gel Network ◽

Silver Mercaptide ◽

Basic Phase ◽

Key Parameter

В настоящей работе сформулированная ранее мезоскопическая модель цистеин-серебряного раствора, в которой кластеры меркаптида серебра рассматриваются как жесткие «липкие» сферы, реализована на базе программного пакета LAMMPS. Ключевым параметром, оказывающим непосредственное влияние на морфологию формирующихся агрегатов и поведение системы в целом, является концентрация соли. Выполненные тестовые расчеты показывают, что построенная модель может воспроизводить этап созревания, образование волокон гель сетки и коагуляции цистеин-серебряного раствора на мезомасштабном уровне. In this work, the previously formulated mesoscopic model of a cysteine-silver solution, in which silver mercaptide clusters are considered as hard «sticky» spheres, is implemented on the basis of the LAMMPS software package. The key parameter that has a direct impact on the morphology of the forming aggregates and the behavior of the system depends on the salt concentration. The test calculations show that the constructed model can reproduce the stage of the maturation, the formation of the fibers of the gel-network and the coagulation of the cysteine-silver solution at the mesoscale level.

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Making and Breaking of Gels: Stimuli-Responsive Properties of Bis(Pyridyl-N-oxide Urea) Gelators

Molecules ◽

10.3390/molecules26216420 ◽

2021 ◽

Vol 26 (21) ◽

pp. 6420

Author(s):

Sreejith Sudhakaran Jayabhavan ◽

Dipankar Ghosh ◽

Krishna K. Damodaran

Keyword(s):

Structural Modification ◽

Sol Gel ◽

Stimuli Responsive ◽

Responsive Materials ◽

Sol Gel Transition ◽

Rheological Experiments ◽

The Stability ◽

External Stimuli ◽

Chloride Salts ◽

Gel Network

The structural modification of existing supramolecular architecture is an efficient strategy to design and synthesize supramolecular gels with tunable and predictable properties. In this work, we have modified bis(pyridyl urea) compounds with different linkers, namely hexylene and butylene, to their corresponding bis(pyridyl-N-oxide urea). The gelation properties of both the parent and the modified compounds were studied, and the results indicated that modification of the 3-pyridyl moieties to the corresponding 3-pyridyl-N-oxides induced hydrogelation. The stability of the parent and modified compounds were evaluated by sol-gel transition temperature (Tgel) and rheological measurements, and single-crystal X-ray diffraction was used to analyze the solid-state interactions of the gelators. The morphologies of the dried gels were analyzed by scanning electron microscopy (SEM), which revealed that the structural modification did not induce any prominent effect on the gel morphology. The stimuli-responsive behavior of these gels in the presence of salts in DMSO/water was evaluated by rheological experiments, which indicated that the modified compounds displayed enhanced gel strength in most cases. However, the gel network collapsed in the presence of the chloride salts of aluminum(III), zinc(II), copper(II), and cadmium(II). The mechanical strength of the parent gels decreased in the presence of salts, indicating that the structural modification resulted in robust gels in most cases. The modified compounds formed gels below minimum gel concentration in the presence of various salts, indicating salt-induced gelation. These results show the making and breaking ability of the gel network in the presence of external stimuli (salts), which explains the potential of using LMWGs based on N-oxide moieties as stimuli-responsive materials.

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Sol-gel transition in silica alkaline solutions. A NMR study

Journal de Chimie Physique ◽

10.1051/jcp/1994910901 ◽

1994 ◽

Vol 91 ◽

pp. 901-908 ◽

Cited By ~ 2

Author(s):

H Zanni ◽

P Nieto ◽

L Fernandez ◽

R Couty ◽

P Barret ◽

...

Keyword(s):

Sol Gel ◽

Alkaline Solutions ◽

Nmr Study ◽

Sol Gel Transition ◽

Gel Transition

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Mesoscopic gelation of chitosan and genipin at below critical concentrations

10.26434/chemrxiv.5487172.v1 ◽

2017 ◽

Author(s):

Christoph Engwer ◽

Ronja Loy ◽

Ioannis S. Chronakis ◽

Ana C. Mendes ◽

Francisco M. Goycoolea

Keyword(s):

Sol Gel ◽

Crosslinking Agent ◽

Small Deformation ◽

Macroscopic Appearance ◽

Critical Concentrations ◽

Gelation Kinetics ◽

Gardenia Jasminoides ◽

Sol Gel Transition ◽

Low Cytotoxicity ◽

High Concentrations

Genipin is increasingly used as a crosslinking agent for chitosans due to its low cytotoxicity as a naturally occurring extract of the plant <i>Gardenia jasminoides</i>. Genipin reacts with the primary amino groups of chitosan to form blue hydrogels. We studied the gelation kinetics of different chitosans varying in their properties (molar mass 34 000-213 000 g mol<sup>-1</sup>, degree of acetylation 9-20%) and genipin in detail. We found that critical sol-gel transition times obtained from dynamic light scattering were in good agreement with the results obtained by small deformation oscillatory rheometry and microviscosimetry at high concentrations of chitosan. However, at below critical concentrations, we found a second regime of gelation that followed the same Ross-Murphy's gelation kinetics. The macroscopic appearance of these samples was a suspension of weak gel-like particles that were sensitive to mechanical forces. We believe that the material is a mesoscopic gel, as described for other polymers. To the best of our knowledge, this is the first time that this phenomenon has been described for the gelling system of chitosan and genipin.

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Sol-gel transition in agar-gelatin mixtures studied with transient elastography

IEEE Transactions on Ultrasonics Ferroelectrics and Frequency Control ◽

10.1109/tuffc.2006.1621498 ◽

2006 ◽

Vol 53 (4) ◽

pp. 716-723 ◽

Cited By ~ 26

Author(s):

J.-L. Gennisson ◽

G. Cloutier

Keyword(s):

Transient Elastography ◽

Sol Gel ◽

Sol Gel Transition ◽

Gel Transition

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Synthesis of Nanogels: Current Trends and Future Outlook

Gels ◽

10.3390/gels7020036 ◽

2021 ◽

Vol 7 (2) ◽

pp. 36

Author(s):

Emanuele Mauri ◽

Sara Maria Giannitelli ◽

Marcella Trombetta ◽

Alberto Rainer

Keyword(s):

3D Printing ◽

Ad Hoc ◽

Sol Gel ◽

Controlled Polymerization ◽

Current Trends ◽

Chip Technology ◽

Physico Chemical ◽

Physical Interactions ◽

Sol Gel Transition ◽

Gel Transition

Nanogels represent an innovative platform for tunable drug release and targeted therapy in several biomedical applications, ranging from cancer to neurological disorders. The design of these nanocarriers is a pivotal topic investigated by the researchers over the years, with the aim to optimize the procedures and provide advanced nanomaterials. Chemical reactions, physical interactions and the developments of engineered devices are the three main areas explored to overcome the shortcomings of the traditional nanofabrication approaches. This review proposes a focus on the current techniques used in nanogel design, highlighting the upgrades in physico-chemical methodologies, microfluidics and 3D printing. Polymers and biomolecules can be combined to produce ad hoc nanonetworks according to the final curative aims, preserving the criteria of biocompatibility and biodegradability. Controlled polymerization, interfacial reactions, sol-gel transition, manipulation of the fluids at the nanoscale, lab-on-a-chip technology and 3D printing are the leading strategies to lean on in the next future and offer new solutions to the critical healthcare scenarios.

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