Structural and viscoelastic properties of slightly interconnected polymer networks immersed in a solvent have been studied in two cases: when the polymer network is building up and when the polymer network is shrinking stepwise in a controlled way. To accomplish this goal, the mean square displacement (MSD) of embedded microspheres in the polymer network was measured as a function of time, with diffusive wave spectroscopy. Particle motion was analyzed in terms of a model, based on a Fokker-Planck type equation, developed for describing particles in Brownian motion within a network that constrain their movement. The model reproduces well the experimental features observed in the MSD vs t curves. The variation of the parameters describing the structure of the network can be understood as the polymerization comes about, and also after the successive volume contractions. In addition, from the MSD curves, the complex shear moduli were obtained in a wide range of frequencies when the network is building up, and at the different shrinking states of the network. Our microrheological results give an insight about the dynamics of embedded particles in slightly interconnected networks, which were also compared with similar results for polymers without interconnections and polymer gels.
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http://dx.doi.org/10.1021/jp4105344 | DOI Listing |
J Neurol
January 2025
Department of Neurology and Neurosciences, Donostia University Hospital, Biogipuzkoa Health Research Institute, Donostia-San Sebastián, Spain.
Background: Alpha-actinin-2, a protein with high expression in cardiac and skeletal muscle, is located in the Z-disc and plays a key role in sarcomere stability. Mutations in ACTN2 have been associated with both hypertrophic and dilated cardiomyopathy and, more recently, with skeletal myopathy.
Methods: Genetic, clinical, and muscle imaging data were collected from 37 patients with an autosomal dominant ACTN2 myopathy belonging to 11 families from Spain and Belgium.
J Neurol
January 2025
Department of Neurology, University Hospital Frankfurt, Frankfurt Am Main, Germany.
Background: BDNF has increasingly gained attention as a key molecule controlling remyelination with a prominent role in neuroplasticity and neuroprotection. Still, it remains unclear how BDNF relates to clinicoradiological characteristics particularly at the early stage of the disease where precise prognosis for the further MS course is crucial.
Methods: BDNF, NfL and GFAP concentrations in serum and CSF were assessed in 106 treatment naïve patients with MS (pwMS) as well as 73 patients with other inflammatory/non-inflammatory neurological or somatoform disorders using a single molecule array HD-1 analyser.
Nano Lett
January 2025
State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, P. R. China.
Osmotic power extracts electricity from salinity gradients and provides a viable route toward clean energy. To improve the energy conversion efficiency, common strategies rely on fabricating precisely controlled nanopores to meet the requirements of high ionic conductivity and selectivity. We report ion transport through the free-volume networks in stacked polymer nanospheres for osmotic power harvesting.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Conjugated polymer donors have always been one of the important components of organic solar cells (OSCs), particularly those featuring simple synthetic routes, proper energy levels, and appropriate aggregation behavior. In this work, we employed a nonfused electron-deficient building block, dicyanobithiophene (2CT), for constructing high-performance donors. Combining this with side-chain engineering, two novel halogen-free polymer donors, PB2CT-BO and PB2CT-HD, were reported.
View Article and Find Full Text PDFMacromol Rapid Commun
January 2025
Qingdao Innovation and Development Center, Harbin Engineering University, Qingdao, 266000, China.
Hydrogels are flexible materials characterized by a 3D network structure, which possess high water content and adjustable physicochemical properties. They have found widespread applications in tissue engineering, electronic skin, drug delivery, flexible sensors, and photothermal therapy. However, hydrogel networks often exhibit swelling behavior in aqueous environments, which can result in structural degradation and a loss of gel performance.
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