Kaolin-Enhanced Superabsorbent Composites: Synthesis, Characterization and Swelling Behaviors

One type of low-cost and eco-friendly organic‒inorganic superabsorbent composite (SAPC) was synthesized by free radical polymerization of acrylic acid (AA), starch (ST), sodium alginate (SA) and kaolin (KL) in aqueous solution. The structure and morphology of the SAPC were characterized by Fourier transform infrared spectrometer (FT-IR), scanning electron microscope (SEM), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The influence of different reaction conditions on water absorption of SAPC, i.e., SA and KL contents, AA neutralization degree (ND), potassium persulfate (KPS) and N, N′-methylenebisacrylamide (MBA) loading were systematically studied. Under the optimal synthesis conditions, very high water absorption of 1200 g/g was achieved. The swelling kinetic mechanism of SAPC was studied by pseudo-second order swelling kinetics model and Ritger‒Peppas model. The performances of SAPC under different environments were tested and results revealed that this new SAPC had excellent swelling capacity, high water retention, good salt tolerance in monovalent salt solution (NaCl solution) and good pH tolerance between 4 and 10.

Effect of monovalent salt concentration and peptide secondary structure in peptide-micelle binding

We report computational (∼14.2 μs of MD) and experimental (CD, fluorescence) investigations to examine the salt-sensitivity and the role of the peptide secondary structure on LL-14 binding to simple membrane mimetic systems.

Liquid Crystal Coacervates Composed of Short Double Stranded DNA and Cationic Peptides

<p>Phase separation of nucleic acids and proteins is a ubiquitous phenomenon regulating sub-cellular compartment structure and function. While complex coacervation of flexible single stranded nucleic acids is broadly investigated, coacervation of double stranded DNA (dsDNA) is less studied because of its propensity to generate solid precipitates. Here, we reverse this perspective by showing that short dsDNA and poly-L-lysine coacervates can escape precipitation while displaying a surprisingly complex phase diagram, including the full set of liquid crystal (LC) mesophases observed to date in bulk dsDNA. LC-coacervate structure was characterized upon variations in temperature and monovalent salt, DNA and peptide concentrations, which allow continuous transitions between all accessible phases. A deeper understanding of LC-coacervates can gain insights to decipher structures and phase transition mechanisms within biomolecular condensates, to design stimuli-responsive multi-phase synthetic compartments with different degrees of order and to exploit self-assembly driven cooperative prebiotic evolution of nucleic acids and peptides.</p>

Liquid Crystal Coacervates Composed of Short Double Stranded DNA and Cationic Peptides

<p>Phase separation of nucleic acids and proteins is a ubiquitous phenomenon regulating sub-cellular <a>compartment </a>structure and function. While complex coacervation of flexible single stranded nucleic acids is broadly investigated, coacervation of double stranded DNA (dsDNA) is less studied because of its propensity to generate solid precipitates.Here, we reverse this perspective by showing that short dsDNA and poly-L-lysine coacervates can escape precipitation while displaying a surprisingly complex phase diagram, including the full set of liquid crystal (LC) mesophases observed to date in bulk dsDNA. LC-coacervate structure was characterized upon variations in temperature and monovalent salt, DNA and peptide concentrations, which allow continuous transitions between all accessible phases. A deeper understanding of LC-coacervates can gain insights to decipher structures and phase transition mechanisms within biomolecular condensates, to design stimuli-responsive multi-phase synthetic compartments with different degrees of order and to exploit self-assembly driven cooperative prebiotic evolution of nucleic acids and peptides.</p>

Liquid Crystal Coacervates Composed of Short Double Stranded DNA and Cationic Peptides

<p>Phase separation of nucleic acids and proteins is a ubiquitous phenomenon regulating sub-cellular compartment structure and function. While complex coacervation of flexible single stranded nucleic acids is broadly investigated, coacervation of double stranded DNA (dsDNA) is less studied because of its propensity to generate solid precipitates. Here, we reverse this perspective by showing that short dsDNA and poly-L-lysine coacervates can escape precipitation while displaying a surprisingly complex phase diagram, including the full set of liquid crystal (LC) mesophases observed to date in bulk dsDNA. LC-coacervate structure was characterized upon variations in temperature and monovalent salt, DNA and peptide concentrations, which allow continuous transitions between all accessible phases. A deeper understanding of LC-coacervates can gain insights to decipher structures and phase transition mechanisms within biomolecular condensates, to design stimuli-responsive multi-phase synthetic compartments with different degrees of order and to exploit self-assembly driven cooperative prebiotic evolution of nucleic acids and peptides.</p>

The Conductance and Swelling of Composite Membrane ‘Chitosan-Silver Nanoparticles’ in Monovalent Salt Solution ‘KCl and NaCl’

A research about to determine the conductance and water absorption capacity (swelling) of the composite membrane has been conducted. The membrane used was a membrane made of chitosan matrix, silver nanoparticle(AgNP) of 100 µg as a filler and acetic acid 1% as a solvent, which named chitosan composite membrane (Ch-AgNP). A 2% chitosan membrane (membrane Ch) used as a comparison. The membrane conductance value determined by measuring the membrane voltage (V) as a function of current (I) in monovalent salt solutions of NaCl and KCl with a concentration of 0.025 M. The swelling tests have been carried out using distilled water. The results showed that Ch membrane conductance was greater than the Ch-AgNP composite membrane. In KCl solution, the conductance is 0.0991 ?-1 and 0.0984 ?-1 and in NaCl solution are 0.1002 ?-1 and 0.0996 ?-1. The membrane conductance is greater in NaCl solution than in KCl solution. The swelling test showed that the swelling percentage of Ch-AgNP composite membrane was greater than Ch membrane