Nucleic acids, such as messenger RNAs, antisense oligonucleotides, and short interfering hold great promise for treating previously 'undruggable' diseases. However, there are numerous biological barriers that hinder nucleic acid delivery to target cells tissues. While lipid nanoparticles (LNPs) have been developed protect acids from degradation mediate their intracellular delivery, it is challenging predict how alterations in LNP formulation parameters influence different organs. In this...

The swelling behavior of poly(2-(diethylamino)ethyl methacrylate) (PDEA) brushes in response to changes solution pH and ionic strength has been investigated. were synthesized by ARGET ATRP methodology at the silica-aqueous interface via two different surface-bound initiator approaches: electrostatically adsorbed cationic macroinitiator covalently anchored silane-based moieties. pH-response these is studied as a function solvated brush thickness constant flow regime that elucidates intrinsic...

The influence of specific anions on the equilibrium thermoresponse poly(N-isopropylacrylamide) (pNIPAM) brushes has been studied using in situ ellipsometry, quartz crystal microbalance with dissipation (QCM-D) and static contact angle measurements between 20 45 °C presence up to 250 mM acetate thiocyanate water. thickness changes exhibited a broad swelling transition spanning approximately 15 from collapsed (high temperatures) swollen conformation (low while brush surface wettability changed...

The anion-specific solvation and conformational behavior of weakly basic poly(2-dimethylamino)ethyl methacrylate (poly(DMA)), poly(2-diethylamino)ethyl (poly(DEA)), poly(2-diisopropylamino)ethyl (poly(DPA)) brushes, with correspondingly increasing inherent hydrophobicity, have been investigated using in situ ellipsometric quartz crystal microbalance dissipation (QCM-D) measurements. In the osmotic brush regime, as initial low concentration salt is increased, brushes osmotically swell by...

The effect of anion identity and temperature on the internal nanostructure poly(N-isopropylacrylamide) brushes were investigated using neutron reflectometry (NR), atomic force microscopy (AFM), quartz crystal microbalance with dissipation monitoring (QCM-D). NR QCM-D measurements showed that addition strongly kosmotropic acetate anions shifted lower critical solution (LCST) to temperatures relative pure D2O/H2O, while chaotropic thiocyanate LCST higher temperatures. Polymer density profiles...

The solvation and swelling behaviour of three dialkylaminoethyl methacrylate polymer brushes, varying hydrophobicity, have been investigated using a combination in situ ellipsometry quartz crystal microbalance with dissipation (QCM-D). At low pH the tertiary amine groups polymers are protonated all brushes significantly solvated swell by adopting an extended conformation. As is increased weak polybasic become increasingly deprotonated collapse via solvent expulsion. By employing high...

Complementary interaction force measurements between an atomic microscope (AFM) tip or colloid probe and a weak polybasic brush have been shown to yield number of fundamental characteristics the its response presence specific anions in aqueous solution. Stretching poly(2-diisopropylamino)ethyl methacrylate (PDPA) chains physisorbed AFM modeling resultant curves allowed persistence contour lengths, molecular weight, thus grafting density be determined. In kosmotropic acetate, high osmotic...

The conformation of a hydrophobic, weak cationic poly(2-diisopropylamino)ethyl methacrylate (PDPA) brush was studied using neutron reflectometry as function aqueous solution pH, ionic strength, and anion identity. In pH 4, 10 mM potassium nitrate the is highly charged, resulting in an extended, dilute conformation; at 9 uncharged collapses to single, dense layer. response added salt constant (4.5) for varying concentrations salts acetate, nitrate, thiocyanate revealed ion-specific...

Hydrophilic and hydrophobic weak polybasic brushes immersed in aqueous solutions of mixed salt counterions are considered using a mean-field numerical self-consistent field approach. On top the solvent quality polymer, counterion-solvent interactions accounted for by implementing Flory-Huggins interaction parameters. We show that ion specificity within brush can bring about large changes conformation. It is found collapse transition hydrophobic, polyelectrolyte features an intermediate...

Neutron reflectometry is the foremost technique for in situ determination of volume fraction profiles polymer brushes at planar interfaces. However, subtle features data produced by these diffuse interfaces challenge interpretation. Historically, analyses have used least-squares approaches that do not adequately quantify uncertainty modeled profile and ignore possibility other structures also match collected (multimodality). Here, a Bayesian statistical approach permits structural...

Polymer brushes are commonly used to modify the properties of solid surfaces. Here a family polybasic poly(2-(diethylamino)ethyl methacrylate) have been grown using ARGET ATRP from cationic macroinitiator adsorbed on two types silica surfaces: QCM crystals and oxidised silicon wafers. The pH-response these is investigated as function brush thickness in constant flow environment order focus intrinsic dynamics polymer brushes. Independent QCM-D situ ellipsometry kinetic studies demonstrate...

The effect of molecular weight and temperature on the phase transition internal structure poly(N-isopropylacrylamide) brush modified colloidal silica particles was investigated using dynamic light scattering (DLS) small angle neutron (SANS) between 15 45 °C. Dry particle analysis utilising transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR) thermogravimetric (TGA) all confirmed thickness polymer shell increased as a function polymerisation time....

Sustaining the current trend toward lower viscosity lubricants requires development of improved friction modifier additives to compensate for increased prevalence boundary lubrication. In this work, we demonstrate that functionalizing oil-soluble olefin copolymers (OCP) with a random distribution small amount (around 1.4 mol %) polar-aromatic groups provides an additive potential enhanced Extensional relaxation time measurements show functionalized copolymer (FOCP) can form transient,...

The temperature induced swelling/collapse transition of poly(oligoethylene glycol methacrylate) (POEGMA) brushes has been investigated in electrolyte solutions comprised multiple anions.

We report the synthesis of new protic ionic liquids (PILs) based on aniline derivatives and use high-throughput (HT) techniques to screen possible candidates. In this work, a simple HT method was applied rapidly different against acids in order identify combinations that produce PILs. This followed by repeating process with Chemspeed robotic platform for more accurate results. One successful were then chosen be synthesised larger scale further analysis. The PILs are interest fields liquids,...

Multi-stimulus responsive poly(2-(2-methoxyethoxy)ethyl methacrylate-co-2-(diethylamino)ethyl methacrylate) [P(MEO2MA-co-DEA)] 80:20 mol % copolymer brushes were synthesized on planar silica substrates via surface-initiated activators continuously regenerated electron transfer atom radical polymerization. Brush thickness was sensitive to changes in pH and temperature as monitored with ellipsometry. At low pH, the brush is charged swollen, while at high uncharged more collapsed. Clear...

The structure of grafted-from poly(N-isopropylacrylamide) (PNIPAM) brushes is investigated as a function confining stress and system temperature using neutron reflectometry (NR), numerical self-consistent field theory, the reanalysis colloid probe atomic force microscopy (AFM) data from literature. For NR experiments, confinement achieved custom-made sample environment, corresponding are analyzed novel "distribution model." AFM experiments similar temperature–stress combinations generally...

Self-stratification of model blends colloidal spheres has recently been demonstrated as a method to form multifunctional coatings in single pass. However, practical coating formulations are complex fluids with upward 15 components. Here, we investigate the influence three different rheology modifiers (RMs) on stratification 10 wt % 7:3 w:w blend 270 and 96 nm anionic latex particles that do not stratify without RM. addition high molar mass polysaccharide thickener, xanthan gum, raises...

Polymer adsorption at the solid/liquid interface depends not only on chemical composition of polymer but also specific placement monomers along sequence. However, challenges in designing polymers with well-controlled sequences have limited explorations into role sequence behavior to molecular simulations. Here, we demonstrate how control offered by polypeptide synthesis can be utilized study effects small changes interface. Through a combination quartz crystal microbalance dissipation...