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The function of biomolecules is tightly linked to their structure, and changes therein. Time‐resolved X‐ray solution scattering has proven a powerful technique for interrogating structural changes and signal transduction in photoreceptor proteins. However, these only represent a small fraction of the biological macromolecules of interest. More recently, laser‐induced temperature jumps have been introduced as a more general means of initiating structural changes in biomolecules. Here we present the development of a setup for millisecond time‐resolved X‐ray solution scattering experiments at the CoSAXS beamline, primarily using infrared laser light to trigger a temperature increase, and structural changes. We present results that highlight the characteristics of this setup along with data showing structural changes in lysozyme caused by a temperature jump. Further developments and applications of the setup are also discussed. A new experimental setup for millisecond time‐resolved X‐ray solution scattering has been developed and commissioned at the CoSAXS beamline at the MAX IV synchrotron. Results from T‐jump experiments induced by infrared laser pulses in lysozyme in solution are presented for validation.

Wheat gluten (WG) and potato protein (PP) were modified to a basic pH by NaOH to impact macromolecular and structural properties. Films were processed by compression molding (at 130 and 150 °C) of WG, PP, their chemically modified versions (MWG, MPP) and of their blends in different ratios to study the impact of chemical modification on structure, processing and tensile properties. The modification changed the molecular and secondary structure of both protein powders, through unfolding and re-polymerization, resulting in less cross-linked proteins. The β-sheet formation due to NaOH modification increased for WG and decreased for PP. Processing resulted in cross-linking of the proteins, shown by a decrease in extractability; to a higher degree for WG than for PP, despite higher β-sheet content in PP. Compression molding of MPP resulted in an increase in protein cross-linking and improved maximum stress and extensibility as compared to PP at 130 °C. The highest degree of cross-linking with improved maximum stress and extensibility was found for WG/MPP blends compared to WG/PP and MWG/MPP at 130 °C. To conclude, chemical modification of PP changed the protein structures produced under harsh industrial conditions and made the protein more reactive and attractive for use in bio-based materials processing, no such positive gains were seen for WG.

Organic–inorganic (O–I) hybrid nanocomposites have already been widely investigated in the optoelectronic industry and are emerging in the biomedical field. In both cases, a thorough knowledge of the O–I hybrid morphology is key for reaching tailored properties of the devices; however, up to now little is known on this matter. Herein, we used advanced X-ray scattering and microscopy techniques to investigate in detail the morphology and nanostructure of a biocompatible, ternary, and semicrystalline O–I hybrid nanocomposite made up of poly(ε-caprolactone) (PCL) and poly(ethylene glycol) (PEG), cross-linked by in situ-generated silsesquioxane structures (SS). Results showed that phase separation occurred at all length scales. At the microscale, irreversible PCL/PEG phase separation generated a globular morphology, where PEG-rich spherical domains were uniformly distributed within a PCL-rich matrix. At the nanoscale, partial organic/inorganic phase segregation resulted in the formation of polysilsesquioxane nanoparticles in both matrix and domains. Finally, an unusual crystalline behaviour was observed for the ternary O–I hybrid nanocomposite, PCL-PEG/SS, where PCL crystallization was anticipated and PEG crystallization was delayed in comparison with the binary PCL/SS and PEG/SS O–I hybrids as well as to a blend of the uncross-linked PCL and PEG precursors. These results provide new insights on how the competing processes of phase separation, crystallization, and inorganic cross-linking affect the overall morphology and nanostructure of O–I hybrid nanocomposites and, therefore, might be useful for establishing relevant structure–property relationships.

Cellulose nanocrystal (CNC) incorporation in polymeric matrices is an environmentally friendly approach to mechanical reinforcement. In general, significant mechanical reinforcement can only be achieved by means of good CNC dispersion at random orientation. These primary characteristics are even more relevant for the preparation of nanocomposites based on hydrophobic matrices, such as poly(ε-caprolactone) (PCL). A straightforward approach to improve CNC dispersion in hydrophobic matrices is their surface modification. However, this extra step is usually complex and often impairs particle–particle interactions, which are also key to mechanical reinforcement. In this work, poly(ε-caprolactone)/neat cellulose nanocrystal nanocomposites were prepared by a specific procedure that combined solvent exchange and solvent casting methodologies, avoiding the use of any additives or chemical modification. These nanocomposites were investigated in terms of the CNC percolation network formation and its effect on the overall mechanical properties. The results showed that significant mechanical reinforcement was obtained, reaching a 155% Young’s modulus increase at 25 wt% CNC content. TEM showed a percolated network in the PCL/CNC25 nanocomposite. In terms of morphology and nanostructure, increasing CNC concentration also promoted a reduction in PCL spherulite size and lamellar thickness. These results pointed out to CNC preferential localization in the interfibrillar region. In conclusion, the solvent exchange methodology presented herein led to mechanically reinforced PCL/CNC nanocomposites with small crystalline domains intertwined with a percolated CNC network.

This study addresses an innovative approach to generate aerated foods with appealing texture through the utilization of lupin protein isolate (LPI) in combination with edible fats. We show the impact of transglutaminases (TGs; SB6 and commercial), glycerol (Gly), soy lecithin (Lec) and linoleic acid (LA) on the micro- and nanostructure of health promoting solid foods created from LPI and fats blends. 3-D tomographic images of LPI with TG revealed that SB6 contributed to an exceptional bubble spatial organization. The inclusion of Gly and Lec decreased protein polymerization and also induced the formation of a porous layered material. LA promoted protein polymerization and formation of homogeneous thick layers in the LPI matrix. Thus, the LPI is a promising protein resource which when in blend with additives is able to create diverse food structures. Much focus has been placed on the great foamability of LPI and here we show the resulting microstructure of LPI foams, and how these were improved with addition of TGs. New food applications for LPI can arise with the addition of food grade dispersant Lec and essential fatty-acid LA, by improved puffiness, and their contributing as replacer of chemical leavening additives in gluten-free products.

The design of supramolecular hydrogels comprising aligned domains is important for the fabrication of biomimetic materials and applications in optoelectronics. One way to access such materials is by the self-assembly of small molecules into long fibres, which can be aligned using an external stimulus. Out-of-equilibrium supramolecular gels can also be designed, where pre-programmed changes of state can be induced by the addition of chemical fuels. Here we exploit these dynamic properties to form materials with aligned domains through a ‘forging’ approach: an external force is used to rearrange the underlying network from random to aligned fibres as the system undergoes a pre-programmed gel-to-sol-to-gel transition. We show that we can predictably organize the supramolecular fibres, leading to controllable formation of materials with aligned domains through a high degree of temporal control. Dynamic supramolecular systems can be designed to adapt phases in a pre-programmable way. Here the transient nature of a gel system is exploited, in combination with the application of mechanical stimuli, to obtain soft materials with aligned fibres in a controllable way.

The microstructural properties of polycrystalline CuO powders and their evolution during controlled high energetic ball milling (HEBM) were studied using conventional X-ray diffraction (XRD) techniques and in situ temperature-dependent small and wide angle scattering (SAXS–WAXS) synchrotron radiation experiments. Volume weighted average grain size, unit cell expansion, oxygen deficiency, and microstrain values as a function of milling time were obtained from XRD. SAXS data revealed different nanostructures for samples synthesized by one-step solid-state reaction (SSR) or HEBM-treated powders. The latter presented the characteristics of a multilayered nanoscale solid system with surface fractal behavior. Correlation of the XRD microstructural parameters and the power law exponent of the SAXS curves as a function of temperature and milling time provided a coherent picture of the structure of HEBM-treated powders. The overall structural information presented in this article may shed some light on the macroscopic physical properties of CuO nanostructures.

For a number of applications, gluten protein polymer structures are of the highest importance in determining end‐use properties. The present article focuses on gluten protein structures in the wheat grain, genotype‐ and environment‐related changes, protein structures in various applications, and their impact on quality. Protein structures in mature wheat grain or flour are strongly related to end‐use properties, although influenced by genetic and environment interactions. Nitrogen availability during wheat development and genetically determined plant development rhythm are the most important parameters determining the gluten protein polymer structure, although temperature during plant development interacts with the impact of the mentioned parameters. Glutenin subunits are the main proteins incorporated in the gluten protein polymer in extracted wheat flour. During dough mixing, gliadins are also incorporated through disulfide‐sulfhydryl exchange reactions. Gluten protein polymer size and complexity in the mature grain and changes during dough formation are important for breadmaking quality. When using the gluten proteins to produce plastics, additional proteins are incorporated in the polymer through disulfide‐sulfhydryl exchange, sulfhydryl oxidation, β‐eliminations with lanthionine formation, and isopeptide formation. In promising materials, the protein polymer structure is changed toward β‐sheet structures of both intermolecular and extended type and a hexagonal close‐packed structure is found. Increased understanding of gluten protein polymer structures is extremely important to improve functionality and end‐use quality of wheat‐ and gluten‐based products.

Nanocomposites comprised of insulated magnetic single-domain particles are promising candidates for high-frequency, eddy current free, soft magnetic materials, but tend to suffer from low magnetic susceptibility (\\(<20\\)). Particle alignment has been proposed to increase nanocomposite susceptibility and reduce magnetic losses but experimental verification has been lacking. Here, magnetic nanocomposites containing 3-57 vol\\% field-aligned 11\\(\\)3 nm maghemite particles in a poly-vinyl matrix were investigated for potential use as high-frequency inductor core materials. The particles were aligned by a homogenous static alignment field during nanocomposite drying, fixating the particle orientation. Particle aggregation was disproved by small-angle scattering. The dependence of the alignment field strength and particle concentration on the nanocomposite's susceptibility and hysteresis losses were investigated from DC up to 922 kHz by vibrating sample magnetometry, AC-susceptibility and high-frequency hysteresis measurements. Nanocomposite susceptibility increased super-linearly with particle fraction due to weak particle interactions. Alignment of the particles increased the nanocomposite susceptibility from 21 to 50 for samples with a particle content of 57 vol\\%. Hence, the synergy between particle alignment and interaction allows for a higher than expected susceptibility of nanocomposites. The results show that magnetically aligning particles in a nanocomposite reduces magnetic losses when using well-dispersed single-domain superparamagnetic nanoparticles. Measured nanocomposite susceptibility could be modelled by a combination of directional dependent Debye-models including mean-field interaction effects and partial particle alignment. Measured susceptibility of 50 is among the highest obtained for nanocomposites, making it a relevant candidate for applications in power electronics.

Glutaraldehyde (GA) reacts with amino groups in proteins, forming intermolecular cross-links that, at sufficiently high protein concentration, can transform a protein solution into a gel. Although GA has been used as a cross-linking reagent for decades, neither the cross-linking chemistry nor the microstructure of the resulting protein gel have been clearly established. Here we use small-angle X-ray scattering (SAXS) to characterise the microstructure and structural kinetics of gels formed by cross-linking of pancreatic trypsin inhibitor, myoglobin or intestinal fatty acid-binding protein. By comparing the scattering from gels and dilute solutions, we extract the structure factor and the pair correlation function of the gels. The protein gels are spatially heterogeneous, with dense clusters linked by sparse networks. Within the clusters, adjacent protein molecules are almost in contact, but the protein concentration in the cluster is much lower than in a crystal. At the \\(\\)1 nm SAXS resolution, the native protein structure is unaffected by cross-linking. The cluster radius is in the range 10 - 50 nm, with the cluster size determined mainly by the availability of lysine amino groups on the protein surface. The development of structure in the gel, on time scales from minutes to hours, appears to obey first-order kinetics. Cross-linking is slower at acidic pH, where the population of amino groups in the reactive deprotonated form is low. These results support the use of cross-linked protein gels in NMR studies of protein dynamics and for modeling NMR relaxation in biological tissue.