Correction: Structure formation of PNIPAM microgels in foams and foam films.

Correction for 'Structure formation of PNIPAM microgels in foams and foam films' by Matthias Kühnhammer , , 2022, , 9249-9262, https://doi.org/10.1039/D2SM01021F.

Dynamic wetting properties of PDMS pseudo-brushes: Four-phase contact point dynamics case.

We investigate the wetting properties of PDMS (Polydimethylsiloxane) pseudo-brush anchored on glass substrates. These PDMS pseudo-brushes exhibit a significantly lower contact angle hysteresis compared to hydrophobic silanized substrates. The effect of different molar masses of the used PDMS on the wetting properties seems negligible.

Light-Controlled Lyotropic Liquid Crystallinity of Polyaspartates Exploited as Photo-Switchable Alignment Medium.

Two polyaspartates bearing -fluorinated azobenzenes (FAB) as photo-responsive groups in the side chain were synthesized: PFABLA () and co-polyaspartate PpFABLA--PBLA [, 75%(n/n) PFABLA content]. As a consequence of the /-isomerization of the side chain, PFABLA () undergoes a visible-light-induced reversible coil-helix transition in solution: Green light (525 nm) affords the coil, and violet light (400 nm) affords the helix. FAB significantly increases the thermal stability of the -isomer at 20 °C ( = 66 d for the -isomer) and effectively counters the favored back formation of the helix.

Structure formation of PNIPAM microgels in foams and foam films.

Responsive aqueous foams are very interesting from a fundamental point of view and for various applications like foam flooding or foam flotation. In this study thermoresponsive microgels (MGs) made from poly(-isopropyl-acrylamide) (PNIPAM) with varying cross-linker content, are used as foam stabilisers. The foams obtained are thermoresponsive and can be destabilised by increasing the temperature.

A new model to describe small-angle neutron scattering from foams.

The modelling of scattering data from foams is very challenging due to the complex structure of foams and is therefore often reduced to the fitting of single peak positions or feature mimicking. This article presents a more elaborate model to describe the small-angle neutron scattering (SANS) data from foams. The model takes into account the geometry of the foam bubbles and is based on an incoherent superposition of the reflectivity curves arising from the foam films and the small-angle scattering (SAS) contribution from the plateau borders.

Optimized signal deduction procedure for the MIEZE spectroscopy technique.

A method is reported to determine the phase and amplitude of sinusoidally modulated event rates, binned into four bins per oscillation, based on data generated at the resonant neutron spin-echo spectrometer RESEDA at FRM-II. The presented algorithm relies on a reconstruction of the unknown parameters. It omits a calculation-intensive fitting procedure and avoids contrast reduction due to averaging effects.

Model Surfaces for Paper Fibers Prepared from Carboxymethyl Cellulose and Polycations.

For tailored functionalization of cellulose based papers, the interaction between paper fibers and functional additives must be understood. Planar cellulose surfaces represent a suitable model system for studying the binding of additives. In this work, polyelectrolyte multilayers (PEMs) are prepared by alternating dip-coating of the negatively charged cellulose derivate carboxymethyl cellulose and a polycation, either polydiallyldimethylammonium chloride (PDADMAC) or chitosan (CHI).

Drastic Swelling of Lipid Oligobilayers by Polyelectrolytes: A Potential Molecular Model for the Internal Structure of Lubricating Films in Mammalian Joints.

Osteoarthritis is the most common arthropathy in western civilization. It is primarily caused by the degeneration of lipid-coated cartilage, leading to increased friction in joints. Hyaluronic acid (HA), a negatively charged polysaccharide and the main component of the synovial fluid, is held responsible for joint lubrication.

Effect of benzocaine and propranolol on phospholipid-based bilayers.

Cell membranes play a fundamental role in protecting the cell from its surroundings, in addition to hosting many proteins with fundamental biological tasks. A study of drug/lipid interactions is a necessary and important step in fully clarifying the role and action mechanism of active ingredients, and shedding light on possible complications caused by drug overdosage. In this paper, the influence of benzocaine and propranolol drugs on the structure of l-α-phosphatidylcholine-based membranes has been investigated by means of neutron reflectivity, grazing incidence small angle neutron scattering, and small/ultra-small angle neutron scattering.

Relationship between Structure and Fluctuations of Lipid Nonlamellar Phases Deposited at the Solid-Liquid Interface.

The structure and dynamics of nanostructure films formed by mixtures of soy phosphatidylcholine and glycerol dioleate at the silicon-aqueous interface were studied by grazing incidence neutron spin echo spectroscopy (GINSES), specular and off-specular neutron reflectometry, and small-angle X-ray diffraction. Reverse hexagonal (H) and micellar cubic phase (Fd3m) layers at the solid-liquid interface have been identified with neutron reflectometry measurements. A preferred orientation of the liquid crystalline (LC) domains was observed only for the anisotropic H phase.

Mesoscopic Correlation Functions in Heterogeneous Ionic Liquids.

A common feature of ionic liquids composed of cations with long aliphatic side chains is structural heterogeneities on the nanometer length scale. This so-called microphase separation arises from the clustering of aliphatic moieties. The temperature dependence of the liquid bulk structure was studied by small-angle X-ray and neutron scattering for a set of methylimidazolium ([CCim], [CCim]) based ionic liquids with tris(pentafluoroethyl)trifluorophosphate ([FAP]), bis(trifluoromethylsulfonyl)imide ([NTf]), and bis(nonafluorobutylsulfonyl)imide ([NNf]) anions.

Sugar Surfactant Based Microemulsions at Solid Surfaces: Influence of the Oil Type and Surface Polarity.

The structure of sugar-surfactant-based bicontinuous microemulsions in the bulk and at hydrophilic and hydrophobic solid planar surfaces was studied by means of neutron scattering techniques (SANS, NR, and GISANS). In particular, the influence of the type of oil (tetradecane and methyl oleate) on the structural properties in the vicinity of surfaces was investigated at different oil-to-water ratios. In the case of hydrophilic surfaces, the analysis of the scattering length density profiles reveals an induced ordering of the oil and water domains perpendicular to the solid-liquid interface in both sets of microemulsions.

Temperature responsive behavior of polymer brush/polyelectrolyte multilayer composites.

The complex interaction of polyelectrolyte multilayers (PEMs) physisorbed onto end-grafted polymer brushes with focus on the temperature-responsive behavior of the system is addressed in this work. The investigated brush/multilayer composite consists of a poly(styrene sulfonate)/poly(diallyldimethylammonium chloride) (PSS/PDADMAC) multilayer deposited onto the poly(N-isopropylacrylamide-b-dimethylaminoethyl methacrylate) P(NIPAM-b-DMAEMA) brush. Ellipsometry and neutron reflectometry were used to monitor the brush collapse with the thickness decrease as a function of temperature and the change in the monomer distribution perpendicular to the substrate at temperatures below, across and above the phase transition, respectively.

Interactions of PAMAM dendrimers with negatively charged model biomembranes.

We have investigated the interactions between cationic poly(amidoamine) (PAMAM) dendrimers of generation 4 (G4), a potential gene transfection vector, with net-anionic model biomembranes composed of different ratios of zwitterionic phosphocholine (PC) and anionic phospho-L-serine (PS) phospholipids. Two types of model membranes were used: solid-supported bilayers, prepared with lipids carrying palmitoyl-oleoyl (PO) and diphytanoyl (DPh) acyl chains, and free-standing bilayers, formed at the interface between two aqueous droplets in oil (droplet interface bilayers, DIBs) using the DPh-based lipids. G4 dendrimers were found to translocate through POPC:POPS bilayers deposited on silica surfaces.

Molecular recognition of nucleic acids by nucleolipid/dendrimer surface complexes.

We show for the first time that 1,2-dilauroyl-sn-glycero-3-phosphatidyladenosine nucleolipid surface complexes with cationic poly(amidoamine) dendrimers can be used to selectively bind DNA including oligonucleotides. This molecular recognition has high potential for applications involving biomedical and bioanalytic devices as well as drug delivery systems based on nucleic acids.

Aggregation and rearrangement within a silver nanoparticle layer during polyelectrolyte multilayer formation.

Silver nanoparticles (4.5 nm average radius) are used as the first negatively charged layer of a polyelectrolyte multilayer prepared subsequently from poly(allylamine hydrochloride) (PAH) and poly(styrenesulfonate) (PSS) solutions with 1 M KCl. After adsorption of a PAH layer on top of the silver nanoparticle monolayer, particle aggregation occurs, as evidenced by the double peak of the UV-vis absorption spectrum and by the decreased number of the objects found with AFM.