An investigation of the volume transition in colloidal core−shell particles composed a temperature-independent polystyrene core and shell thermosensitive cross-linked polymer chains by small-angle X-ray scattering (SAXS) is presented. The PS cores have diameter 80 nm whereas poly(N-isopropylacrylamide) has thickness 32 swollen state at 25 °C 18 after shrinking continuous transition. SAXS intensities measured high angles could be described Lorentz-type function both states. This indicates...

Time-resolved synchrotron small-angle X-ray scattering (SAXS) studies were performed to investigate the unseeded formation and growth of colloidal calcium carbonate particles. Equimolar aqueous solutions CaCl2·2H2O Na2CO3 rapidly mixed in a stopped-flow apparatus, SAXS data recorded using an image-intensified CCD detector. It is shown that allows studying those processes situ, with very good time resolution. can provide unsurpassed real-time information about particle size, shape,...

We use small-angle x-ray scattering (SAXS) as a tool to study the binding of proteins spherical polyelectrolyte brushes (SPB) in situ. The SPB consists solid core \ensuremath{\sim} 100 nm diam onto which long chains [poly(styrene sulfonic acid, PSS) and poly(acrylic PAA)] have been densely grafted. used this investigation, Bovine Serum Albumine (BSA) Pancreatic Ribonuclease A (RNase A), adsorb strongly these if ionic strength is low despite their negative charge. Virtually no adsorption...

We propose a theory for the effective interaction between soft dendritic molecules that is based on shape of monomer density profile macromolecules at infinite dilutions. By applying Flory-type arguments and making use experimentally measured profiles, we derive Gaussian whose parameters are determined by size number dendrimers derived from small-angle neutron scattering (SANS) measurements. this to concentrated dendrimer solutions calculate theoretical structure factors compare them with...

The volume transition in thermosensitive colloidal core–shell particles is investigated by small-angle x-ray scattering (SAXS), Neutron (SANS), and dynamic light (DLS). latex are dispersed water consist of a solid poly(styrene) core with diameter 100 nm. shell made up poly(N-isopropylacrylamide) (PNIPA) chains crosslinked 2.5 mol % N,N’-methylenbisacrylamide (BIS). Water good solvent for PNIPA at room temperature but becomes poor above 32 °C. network the undergoes this temperature. As result...

The transformation of amorphous colloidal calcium carbonate into single microcrystals was observed in supersaturated solutions situ. observations are done by simultaneous time-resolved small-angle and wide-angle X-ray scattering experiments (TR-SAXS/WAXS) at a third generation synchrotron source. TR-SAXS/WAXS demonstrates that the particles generated reaction Ca2+ CO32- ions amorphous. these CaCO3 proceeds via dissolution subsequent heterogeneous nucleation crystalline modification on walls...

We present an analysis of the distribution end groups within a urea-functionalized poly(propyleneamine) dendrimer fourth generation by small-angle neutron scattering (SANS). The phenyl have been deuterated to enhance their contrast. SANS experiments are performed using solution labeled in mixtures protonated and dimethylacetamide (DMA). In this way contrast between solute solvent is varied systematic fashion (contrast variation). presented here gives three partial functions that depend...

Alpha,omega-hydrogen donor/acceptor functional polymer strands are prepared via a combination of living radical polymerization and orthogonal conjugation subsequently self-assembled as single chains to emulate--on simple level--the self-folding behaviour natural biomacromolecules.

High-performance polystyrene (PS)–polyisoprene (PI) low-disperse thermoplastic elastomers with a well-defined pom-pom topology are synthesized via anionic polymerization techniques, where two stars each about 13 PS-b-PI arms connected by linear PS chain, PI forming the inner core of star. Samples 70, 50, 30, and 10 vol % total content were prepared. First, PI-b-PS-b-PI triblock copolymer (short block, Mw,PI = 5 kg mol–1, Mw,PS 100 mol–1) was polymerization; second, blocks functionalized...

We present an investigation of thermosensitive core–shell particles by small-angle neutron scattering (SANS). The consist a solid poly(styrene) core and shell crosslinked poly(N-isopropylacrylamide) (PNIPA) chains. These latex are dispersed in water have diameter ca. 150 nm. At ambient temperature the PNIPA-network is swollen but at higher expelled undergoes continuous volume transition. radial extension investigated as function use SANS. analysis SANS performed different contrasts using...

We have used anomalous small-angle X-ray scattering (ASAXS) to investigate the spatial correlation of counterions with a macroion consisting polyelectrolyte brushes. The spherical brush is composed solid poly(styrene) core 68 nm radius dense grafting linear poly(acrylic acid) chains and rubidium counterions. ASAXS allows one evaluate distribution by exploiting selective variation in contrast near absorption edge rubidium. deduced shows that they are closely correlated polymer macroion....

Abstract Kunststoffe, die aus nachwachsenden Rohstoffen hergestellt werden, gewinnen als Produkte eine immer größere Bedeutung. Aufgrund der einfachen Bearbeitung sind vor allem Thermoplaste von besonderem Interesse. Derzeit allerdings nur thermoplastische Kunststoffe mit aromatischen Bausteinen wie z. B. Terephthalsäure verfügbar, petrochemischen werden. Bekannte Beispiele Polyethylenterephthalat und Polytrimethylenterephthalat. Eine mögliche Alternative ist Furan‐2,5‐dicarbonsäure, werden...

Abstract In this paper the particle size distribution of SiO 2 spherical nanoparticles is determined by small angle X‐ray scattering (SAXS). The experimental intensity data were compared with theoretical intensities based on different numeric procedures and assumptions for particles. Hereby two fixed shapes distribution, Gauss log normal, used to a free which maximum entropy method (MEM). results further distributions obtained from transmission electron microscopy (TEM) analytical...

In-situ flow alignment kinetics of a self-assembled lamellar phase polystyrene-block-polyisoprene (PS-b-PI, Mw = 26 500 g/mol, fPS 51%) diblock copolymer melt has been investigated in detail under mechanical large amplitude oscillatory shear (LAOS) utilizing unique Rheo–SAXS combination developed cooperation with the German Electron Synchrotron (DESY) Hamburg. This marks first time that strain and dependence shear-induced macroscopic perpendicular orientation microstructure could be...

Shape-persistent macrocycles with a rigid pyridyl core and flexible oligo-alkyl corona aggregate to some extent in nonpolar solvents form large (tubular) aggregates. To increase the assembling tendency, intraannular groups of were alkylated. Unexpectedly, quarternized show no tendency at all tubular micellar-like structures but well-defined dimers, as determined by X-ray dynamic light scattering.

Abstract Small‐angle X‐ray scattering (SAXS) is a tool which allows the study of structure and interaction polymer latexes with great accuracy. The low electron density polymers used for synthesis latex particles as e.g. polystyrene matching contrast by adding sucrose to serum. Thus, intensities measured at different contrast, i.e., excess densities can be evaluated (contrast variation). This yields precise information on radial particles. In this article recent SAXS‐investigations are...

We present a study of rod-like polyelectrolyte by anomalous small-angle X-ray scattering (ASAXS). The consists stiff poly(p-phenylene) backbone with attached positive charged groups that are balanced bromine counterions. data taken far below the absorption edge (13 473.7 eV) and in its immediate neighborhood. decrease measured intensity predicted theory is directly observed. A new analysis these ASAXS-data leads to three partial intensities numerically self-consistent fashion. In particular,...

The analysis of concentrated solutions a dendrimer G4 fourth generation by small-angle neutron scattering (SANS) is presented. determination the structure factor S(q) (q = (4π/λ)sin(θ/2); λ: wavelength radiation; θ: angle) from experimental data discussed in detail. It shown that incoherent contribution Iincoh to measured intensity may profoundly disturb S(q), particular at high concentrations solute molecules. Contrast variation used determine which subtracted subsequently intensities....

Typical characterization of nanoparticle dispersion and compounding processes by dynamic light scattering (DLS) TEM lack quantitative information on fractal structure, aggregation number, specific surface area. In this work a synchrotron ultra-small-angle X-ray (USAXS) investigation diffusion flame 'Aerosil' silica powders, as well their desagglomeration high-pressure liquid (200-1400 bar) is presented. Primary particle size, polydispersity, area are measured for stirred-in dispersions,...

A highly sensitive rheodielectric experimental setup was used to investigate the macroscopic alignment of symmetric poly(styrene-b-1,4-isoprene) (SI) diblock copolymers under large-amplitude oscillatory shear (LAOS). The dielectric normal-mode 1,4-cis-polyisoprene chains in copolymer chosen probe situ orientation process. It shown that development overall lamellar microstructure can be followed using time progression loss modulus ε″(t). ε″(t) correlates directly with nonlinear mechanical...

Well-defined three-arm and four-arm star polymers designed via a Z-group approach carrying trithiocarbonate functionalities at the core are prepared reversible addition-fragmentation chain transfer (RAFT) polymerization featuring molecular weights of Mn,SEC = 156 kDa, Đ 1.16 (3-arm) 162 1.15 (4-arm) based on multi-angle laser light scattering (MALLS) detection, respectively. The star-shaped polystyrenes subjected (in bulk) to thermal stress in temperature range between 140 200 °C from 10...

The packing of latex spheres achieved in the first step film formation is considered. latexes consisting PMMA or poly(styrene) particles were dried at temperatures far below glass temperature both materials. weight-average diameters between 69 and 106 nm whereas standard deviation size distribution was located 4.8 12%. spatial order bulk samples thus obtained investigated using small-angle X-ray scattering (SAXS). SAXS allows to study dilute suspension samples. These data yielded structure...

The influence of an adsorbed layer a surfactant on the flow behavior latex is considered. system studied consists poly(styrene) core without chemically bound charges (diameter: 146 nm) and poly(ethylene oxide) chains (length: 80 ethylene oxide units) affixed to surface particles through adsorption Lutensol AT80 (C16-18EO80). Both as well covered by have been small-angle X-ray scattering (SAXS). hydrodynamic thickness was determined rheology be 11.7 nm whereas SAXS gives extension...