Frontiers in Soft Matter最新文献

{"title":"Constraining effects on polymer chain relaxation in crosslinked supramolecular dual networks","authors":"Jasper Feng, J. Allgaier, M. Kruteva, S. Förster, W. Pyckhout-Hintzen","doi":"10.3389/frsfm.2023.1221803","DOIUrl":"https://doi.org/10.3389/frsfm.2023.1221803","url":null,"abstract":"Polymer networks containing transient physical and permanent chemical cross-links exhibit unique mechanical properties due to the intrinsic reassociating ability of supramolecular functional groups. Similar to supramolecular gels, these networks allow the controlled release of stored energy and can extend the life of polymer networks in practical applications. In this study, we investigated the rheology, dielectric spectroscopy, stress–strain behavior, and dynamic mechanical analysis of networks based on long polybutylene oxide (PBO) chains functionalized with randomly placed thymine (Thy) side groups. A transient network was formed by proportionally mixing this matrix with short non-entangled linear 1,3,5-diaminotriazine (DAT) head–tail modified PBO chains, exploiting the hetero-complementarity of the DAT–Thy triple hydrogen bond. This transient polymer network was further cross-linked to a dual network via a thiol-ene click reaction to form static covalent bonds. In PBO, the similar polarity of the PBO matrix and the DAT–Thy functional groups ensures that the molecular chain motion is not affected by segregation, resulting in a homogeneous polymer phase without microphase-separated functional group domains. Dielectric relaxation spectroscopy was combined with rheology to quantify the relaxation processes of the interconnected polymers and the strength of the DAT–Thy bonding interactions in the melt. The results showed two distinct plateaux in the relaxation modulus due to contributions from hydrogen and permanent bonds. In the case of the dual network, the lifetime of the hydrogen bond was prolonged and higher activation energy was observed due to the physical cross-link preventing the movement of the long chain.","PeriodicalId":409762,"journal":{"name":"Frontiers in Soft Matter","volume":"95 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116496685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Surfactant-free self-assembled mesoscale structures in multicomponent mixtures comprising solids, liquids, and gases: nanoparticles, nanodroplets, and nanobubbles","authors":"M. Sedlák","doi":"10.3389/frsfm.2023.1225709","DOIUrl":"https://doi.org/10.3389/frsfm.2023.1225709","url":null,"abstract":"This mini review critically discusses self-assembled mesoscale structures (dimensions between molecular and macroscopic) forming in multicomponent mixtures comprising 1) liquids or 2) liquids and solids or 3) liquids and gases. The common feature of the discussed structures is absence of surfactants. Covered are solvophobicity-driven mesoscale structures (including metastable ouzo-type particles with finite lifetimes), surfactant-free microemulsions, and bulk nanobubbles. The emphasis is mainly on critical analysis of experimental data and suitability of available experimental methods with focus on unambiguous differentiation between various types of mesoscale structures.","PeriodicalId":409762,"journal":{"name":"Frontiers in Soft Matter","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131637710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Applying soft matter techniques to solve challenges in cryopreservation","authors":"Saffron J. Bryant, A. Elbourne, T. Greaves, G. Bryant","doi":"10.3389/frsfm.2023.1219497","DOIUrl":"https://doi.org/10.3389/frsfm.2023.1219497","url":null,"abstract":"Cryopreservation allows the long-term storage of biological material, and has become integral for numerous applications including assisted reproductive technologies, stem cell therapies, blood banking, and species preservation. However, there are still hundreds of cell types that cannot be cryopreserved, and no organs at all. The biggest challenge facing cryopreservation is the ongoing reliance on predominantly just two cryoprotectants (dimethylsulfoxide and glycerol) as well as physical limitations to heating and cooling rates. The field of soft matter can accelerate cryopreservation research by providing insights into the underlying mechanisms and interactions of cells, cryoprotectants, and solvents including the role of temperature. With techniques as far ranging as differential scanning calorimetry, atomic force microscopy, and neutron and X-ray scattering, it is possible to probe multiple length and time scales in order to identify and characterise important interactions. This in turn can lead to the development of new cryoprotectants, and new methods of heating/cooling which could overcome some of the current challenges of cryopreservation.","PeriodicalId":409762,"journal":{"name":"Frontiers in Soft Matter","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126258407","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Crystallinity and perfection in ethylene vitrimers probed by combined calorimetry, scattering, and time-domain NMR","authors":"K. Saalwächter, Bhaskar Soman, C. M. Evans","doi":"10.3389/frsfm.2023.1208777","DOIUrl":"https://doi.org/10.3389/frsfm.2023.1208777","url":null,"abstract":"The kinetics of crystallization and crystal-crystal transformations in ethylene vitrimers are studied by time-domain NMR. These vitrimers previously exhibited polymorphic transition of crystal structures, which are shown here to be distinguishable by NMR via their dipolar line widths based upon different proton densities and fast internal motions. The conditions under which the polymorphs are formed and interconvert are identified via time-resolved NMR experiments, with a focus on recrystallization after full and partial melting. DSC experiments are used to clarify an unexpected superheating effect, which challenges the determination of actual melting points. We further identify a strong memory effect in isothermal (re)crystallization. Implications of the dynamic nature of the vitrimers in relation to the kinetics of crystallization are discussed. We find that internal perfecting of crystals, enabled by the vitrimeric exchange process, can have a large effect on the DSC-detected melting enthalpy without change in overall crystallinity.","PeriodicalId":409762,"journal":{"name":"Frontiers in Soft Matter","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127839705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Benzoxazine/amine-based polymer networks featuring stress-relaxation and reprocessability","authors":"L. Pursche, A. Wolf, Tobias Urbaniak, K. Koschek","doi":"10.3389/frsfm.2023.1197868","DOIUrl":"https://doi.org/10.3389/frsfm.2023.1197868","url":null,"abstract":"Amines as additives in benzoxazines are known to beneficially affect the polymerization temperature and furthermore to allow for partially reversible reaction steps yielding however a non-dynamic polybenzoxazine network. This contribution proves that the polymerization behavior of a two-component polymer of the polyetheramine Jeffamine® ED-600 and a bisphenol-A-based benzoxazine features stress-relaxation and reprocessability usually known from vitrimers. With the aim to gain a deeper understanding of the material properties of this system and the corresponding polymer structure, the reaction mechanism of a monofunctional benzoxazine and monoamine model system was studied revealing at first primary, and then secondary amine induced opening of oxazine rings, leading at first to linear polymer chains and then to covalently crosslinked networks. Both consist of repeated phenolic benzoxazine/amine motifs with permanently incorporated polyetheramine chains that do not impact the mechanical properties, compared to pure polybenzoxazine. Thermal, spectroscopic, and extraction analyses show that the addition of Jeffamine® reduces the polymerization temperature and introduces material properties such as reprocessability at the same time. Stress-relaxation measurements support the assumption that the reprocessability point to vitrimer-like molecular processes. The material shows rapid stress-relaxation of up to 11 s, a corresponding bond-exchange activation energy of 146 kJ/mol, and a topology freezing temperature of 97°C.","PeriodicalId":409762,"journal":{"name":"Frontiers in Soft Matter","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128235767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of particle fluorination on the stability of honey foam","authors":"A. T. Tyowua, Adebukola M. Echendu, S. O. Adejo","doi":"10.3389/frsfm.2023.1163393","DOIUrl":"https://doi.org/10.3389/frsfm.2023.1163393","url":null,"abstract":"Honey foam has applications in the food, cosmetic, and pharmaceutical industries. For example, honey foam can be used in bread or biscuit spread (food industry), as a carrier of topical bioactive ingredients (cosmetic industry), or as a carrier of drugs (pharmaceutical industry). However, the conditions for obtaining a stable honey foam remain unclear. In this study, we investigated the influence of particle fluorination on honey foam volume and foam stability by aerating natural (unadulterated) honey with fluorinated fumed silica (50%–75% SiOH) or fluorinated sericite clay (PF-5–PF-12) particles. Higher foam volume (≤4.3 cm3) and foam stability (up to a year) were observed with the least (75% SiOH) fluorinated fumed silica particles, while lower foam volume and foam stability were observed with the moderately (59% SiOH) and most (50% SiOH) fluorinated fumed silica particles. In contrast, regardless of the degree of fluorination, the fluorinated sericite clay particles yielded little (<1 cm3) and unstable foam that collapsed completely within 4 weeks of preparation. Therefore, with respect to honey foam stabilization, fluorinated fumed silica particles are superior to fluorinated sericite clay particles. These foams can be used for topical formulation of cosmetic and pharmaceutical products, and our findings will guide future stabilization of honey foam for target applications.","PeriodicalId":409762,"journal":{"name":"Frontiers in Soft Matter","volume":"86 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114329792","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Encapsulation of sugar beet phytoglobin BvPgb 1.2 and myoglobin in a lipid sponge phase system","authors":"J. Gilbert, S. Christensen, T. Nylander, L. Bülow","doi":"10.3389/frsfm.2023.1201561","DOIUrl":"https://doi.org/10.3389/frsfm.2023.1201561","url":null,"abstract":"Globins are usually associated with oxygen carriage in vertebrates. However, plants also contain similar heme-containing proteins, called phytoglobins (Pgbs). Unlike conventional hemoglobin, these proteins are often linked to nitric oxide metabolism, energy metabolism and redox maintenance under hypoxic and related abiotic and biotic stress conditions. Class I and II non-symbiotic Pgbs (nsPgbs) have different degrees of heme hexacoordination. This involves direct interaction of the distal histidine in the E-helix with the sixth coordination site of the central iron, resulting in increased stability, in contrast to the oxygen storage linked to pentacoordinated globins, such as myoglobin (Mb). Due to their robustness, nsPgbs have substantial potential for various biomedical applications, particularly for iron supplementation. In this study, a class I nsPgb from sugar beet (Beta vulgaris ssp. vulgaris) was encapsulated in a lipid sponge phase system for potential protein delivery purposes and compared to a similar system of Mb containing nanoparticles. Bulk phases and dispersions were made with two lipid compositions (30/45/25 diglycerol monooleate (DGMO)/Capmul GMO-50/sorbitan monooleate (P80) and 28/42/30 DGMO/GMO-50/P80, where the DGMO/GMO-50 ratio was kept constant at 40/60). In addition, buffer effects on protein loading and particle formation were investigated. High concentrations of BvPgb1.2 (60 mg/mL) showed higher aggregation tendencies than Mb but these appeared to be transient. This property could be coupled to the higher isoelectric point (pI) of the BvPgb1.2 (7.85, compared to 6.8 for Mb), which make it more sensitive to small pH changes. In addition, excess protein/leakage was observed with Mb from the nanoparticles when analysed with size exclusion chromatography. This work highlighted the encapsulation efficiency of these proteins, which might be directly linked to difference in iron coordination and therefore, reactivity and lipid peroxidation. The interactions between the bulk phases and dispersion of the hemeproteins are complex, more research is needed to proper elucidate these relations in more detail, in order to facilitate the encapsulation capacity for heme-containing proteins in similar lipid-based systems.","PeriodicalId":409762,"journal":{"name":"Frontiers in Soft Matter","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131841765","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phase behavior of nematic-nanoparticle mixtures","authors":"Arbresha Hölbl, A. Ranjkesh, Andreja Abina, S. Kralj, A. Zidanšek","doi":"10.3389/frsfm.2023.1193904","DOIUrl":"https://doi.org/10.3389/frsfm.2023.1193904","url":null,"abstract":"We study the effects of nanoparticles (NPs) on thermotropic nematic liquid crystals (LCs) in relatively dilute NP–LC mixtures. We are interested in the fundamental generic mechanisms that quantitatively and qualitatively affect the phase behavior of LCs. A simple molecular field analysis shows that a phase transition will likely occur upon entry into the ordered phase. Moreover, the interaction between nematogenic NPs and LCs could force a sergeant–soldier-like behavior, in which only the phase behavior of one component is affected despite the symmetric appearance of the coupling term. When NPs are anisotropic, their influence on LC phase behavior can be qualitatively different depending on the anchoring, even in the absence of the disorder. We illustrate numerically that a random-field-type disorder might impose either short-range, quasi-long-range, or even long-range order, which might survive.","PeriodicalId":409762,"journal":{"name":"Frontiers in Soft Matter","volume":"83 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123546098","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Novel findings deduced from the microscopic kinetics model contest the classical nucleation theory","authors":"Jun Xu","doi":"10.3389/frsfm.2023.1143168","DOIUrl":"https://doi.org/10.3389/frsfm.2023.1143168","url":null,"abstract":"In this study, we revisit the microscopic kinetics model considering crystal nucleation as reversible attachment and detachment of units from growing clusters. Based on the variation of the rate constants of attaching and detaching with cluster size, we derive some findings that contest the classical nucleation theory. First, the equivalent thermodynamic parameters are deduced from the rate constants, which reveal that the interfacial free energy per area varies with cluster size and finally levels off. Second, if the crystal is not perfect, at the melting point, the nucleation barrier will be definite rather than infinitely large. Third, it is predicted that the critical nuclei size does not vary with supersaturation. Fourth, when the neighboring units from the same polymer chain are used for crystal nucleation, the attaching rate constant should decrease with cluster size, which is distinctly different from the same attaching rate constant in the nucleation of small molecular crystals. These interesting findings show that teaching the old dog (the microscopic kinetics model) new tricks could lead to new findings and deepen our understanding of crystal nucleation.","PeriodicalId":409762,"journal":{"name":"Frontiers in Soft Matter","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127708127","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantifying the tuneable interactions between colloid supported lipid bilayers","authors":"E. Giakoumatos, Berta Gumí Audenis, Á. González García, Laura S van Hazendonk, H. Friedrich, R. Tuinier, I. Voets","doi":"10.3389/frsfm.2023.1110297","DOIUrl":"https://doi.org/10.3389/frsfm.2023.1110297","url":null,"abstract":"Colloid supported lipid bilayers (CSLBs) are formed via the rupture and fusion of lipid vesicles to coat spherical colloidal particles. CSLBs are an emerging vector for the controlled self-assembly of colloids due to the ability to include additives into the bilayer, which influence the (a)specific interactions between particles. To evaluate the specificity of CSLB assembly, first a fundamental study on the tunability of the colloidal interaction and resulting colloidal stability of CSLBs without specific interactions is reported here. It was found that both fluid and gel CSLBs showed significant clustering and attraction, while the addition of steric stabilizers induced a profound increase in stability. The interactions were rendered attractive again by the introduction of depletion forces via the addition of free non-adsorbing polymers. The compositions of fluid and gel CSLBs with 5% membrane stabiliser were concluded to be optimal for further studies where both colloidal stability, and contrasting membrane fluidity are required. These experimental findings were confirmed semi-quantitatively by predictions using numerical self-consistent mean-field theory lattice computations.","PeriodicalId":409762,"journal":{"name":"Frontiers in Soft Matter","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114626859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}