This work examines, first, the non-equilibrium character of the glassy state of polymer systems and its significance in the development of novel materials for important technological applications. Subsequently, it summarizes the essentials of the generalized lattice fluid approach for the description of this highly complex non-equilibrium behavior with an approximate and simple, yet analytically powerful formalism. The working equations are derived in a straightforward and consistent manner by clearly defining the universal and specific variables needed to describe the discussed properties. The role of the non-random distribution of molecular species and free volume in the glassy system is also examined, as is the role of strong specific interactions, such as hydrogen-bonding networks. This work also reports examples of applications in a variety of representative systems, including glass densification, retrograde vitrification, increase in glass-transition temperature in hydrogen-bonded polymer mixtures, and hysteresis phenomena in sorption-desorption from glassy polymer matrices.
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http://dx.doi.org/10.3390/polym16020298 | DOI Listing |
ACS Sens
January 2025
Department of Chemistry, Burke Laboratories, Dartmouth College, 41 College St., Hanover, New Hampshire 03755, United States.
This paper describes the first use of conductive metal-organic frameworks as the active material in the electrochemical detection of nitric oxide in aqueous solution. Four hexahydroxytriphenylene (HHTP)-based MOFs linked with first-row transition metal nodes (M = Co, Ni, Cu, Zn) were compared as thin-film working electrodes for promoting oxidation of NO using voltammetric and amperometric techniques. Cu- and Ni-linked MOF analogs provided signal enhancement of 5- to 7-fold over a control glassy carbon electrode (SA = 6.
View Article and Find Full Text PDFMater Adv
January 2025
Department of Materials Science and Metallurgy, University of Cambridge CB3 0FS UK
The ability to convert light to higher energies through triplet-triplet annihilation upconversion (TTA-UC) is attractive for a range of applications including solar energy harvesting, bioimaging and anti-counterfeiting. Practical applications require integration of the TTA-UC chromophores within a suitable host, which leads to a compromise between the high upconversion efficiencies achievable in liquids and the durability of solids. Herein, we present a series of methacrylate copolymers as TTA-UC hosts, in which the glass transition temperature ( ), and hence upconversion efficiency can be tuned by varying the co-monomer ratios (-hexyl methacrylate (HMA) and 2,2,2-trifluoroethyl methacrylate (TFEMA)).
View Article and Find Full Text PDFAnal Methods
January 2025
Department of Nutrition and Dietetics, Faculty of Health Sciences, Hasan Kalyoncu University, Gazi-antep, 27000, Turkey.
In the present study, a novel voltammetric sensor based on a boron-doped copper oxide/graphene (B-CuO-Gr) nanocomposite and molecularly imprinted polymer (MIP) was developed for the detection of paclobutrazol (PAC) in apple and orange juice samples. The B-CuO-Gr nanocomposite was prepared using sol-gel and calcination methods. After modifying glassy carbon electrodes with the B-CuO-Gr nanocomposite, PAC-imprinted electrodes were prepared in the presence of 100.
View Article and Find Full Text PDFInorg Chem
January 2025
MOE Key Laboratory of Cluster Science, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 102488, China.
A novel antimonotungstate (AT)-based heterometallic framework {[Er(HO)][Fe(Hpdc)(B-β-SbWO)]}·50HO (, Hpdc = pyridine-2,5-dicarboxylic acid) was obtained through a synergistic strategy of in situ-generated transition-metal-encapsulated polyoxometalate (POM) building units and the substitution reaction. Its structural unit is composed of a tetra-Fe-substituted Krebs-type [Fe(Hpdc)(B-β-SbWO)] subunit and two [Er(HO)] cations. This subunit can be regarded as a product of carboxylic oxygen atoms of Hpdc ligands replacing active water ligands in the [Fe(HO)(B-β-SbWO)] species.
View Article and Find Full Text PDFSensors (Basel)
December 2024
Shandong Provincial Key Laboratory of Monocrystalline Silicon Semiconductor Materials and Technology, Shandong Provincial Engineering Research Center of Organic Functional Materials and Green Low-Carbon Technology, Shandong Universities Engineering Research Center of Integrated Circuits Functional Materials and Expanded Applications, College of Chemistry and Chemical Engineering, Dezhou University, Dezhou 253023, China.
In this paper, a novel molecularly imprinted polymer membrane modified glassy carbon electrode for electrochemical sensors (MIP-OH-MWCNTs-GCE) for epinephrine (EP) was successfully prepared by a gel-sol method using an optimized functional monomer oligosilsesquioxane-AlO sol-ITO composite sol (ITO-POSS-AlO). Hydroxylated multi-walled carbon nanotubes (OH-MWCNTs) were introduced during the modification of the electrodes, and the electrochemical behavior of EP on the molecularly imprinted electrochemical sensors was probed by the differential pulse velocity (DPV) method. The experimental conditions were optimized.
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