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This review addresses the impact of different nanoadditives on the glass transition temperature (Tg) of polyvinyl chloride (PVC), which is a widely used industrial polymer. The relatively high Tg limits its temperature-dependent applications. The objective of the review is to present the state-of-the-art knowledge on the influence of nanofillers of various origins and dimensions on the Tg of the PVC. The Tg variations induced by added nanofillers can be probed mostly by such experimental techniques as thermomechanical analysis (TMA), dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), and dielectric thermal analysis (DETA). The increase in Tg is commonly associated with the use of mineral and carbonaceous nanofillers. In this case, a rise in the concentration of nanoadditives leads to an increase in the Tg due to a restraint of the PVC macromolecular chain’s mobility. The lowering of Tg may be attributed to the well-known plasticizing effect, which is a consequence of the incorporation of oligomeric silsesquioxanes to the polymeric matrix. It has been well established that the variation in the Tg value depends also on the chemical modification of nanofillers and their incorporation into the PVC matrix. This review may be an inspiration for further investigation of nanofillers’ effect on the PVC glass transition temperature.

Magnetic magnesium-zinc spinel ferrite Mg 1 −  x Zn x Fe 2 O 4 (where x  = 0.4, 0.6, and 0.8) was investigated as adsorbent for the efficient removal of Sr(II) ions and salicylic acid (SA) contaminants from aqueous medium. The characterization of ferrites was carried out using XRD, VSM, BET, SEM, and EDS. The surface charge of magnetic adsorbents was measured by the drift method. The determination of SA and Sr(II) ion concentrations in the solution phase was carried out by UFLC and complexometry, respectively. It was shown that varying of the Zn(II) content affected the adsorption capacities of magnesium-zinc ferrites. The increasing of zinc content from x (Zn 2+ ) = 0.4 to x (Zn 2+ ) = 0.6 increased the adsorption of Sr(II) ions from 50 to 65 mg/g, and then it was decreased to 36 mg/g for the sample with x (Zn) = 0.8. The Mg 0.4 Zn 0.6 Fe 2 O 4 sample demonstrated the maximum adsorption capacity of 74 mg/g. The adsorption isotherm for Sr(II) was fitted by the Dubinin-Radushkevich, Langmuir, Freundlich, and Sips models. The adsorption kinetics of Sr(II) was analyzed by PFO, PSO, and Elovich models. The adsorption kinetics of SA was also investigated. It was demonstrated that the Mg 0.2 Zn 0.8 Fe 2 O 4 sample exhibited 90% removal of salicylic acid from the water solutions. The results demonstrated that magnetic Mg-Zn ferrites with spinel structure are good sorbents for the removal of SA and Sr(II) ions from aqueous solution.

The following paper presents a study of water dispersion obtained by emulsion co-polymerization of acrylic, methacrylic and vinyl monomers with the use of surfactants. Water dispersions of copolymers used in the production of paints intended for painting surfaces of steel metals and aluminum and its alloys were selected. They were synthesized by ethyl acrylate, butyl acrylate, acrylic acid, methyl methacrylate, methacrylic acid, acrylic acid amide, 2-hydroxyethylacrylate, glycidyl methacrylate, vinyl acetate and 1-ethyl-1-ethylpropylcarbamate (VeoVa 10). The investigated dispersion properties were considered in three groups. It turned out that the dispersions in which the copolymer had the lowest crystallinity temperature and were built of units having hydroxyl, carboxyl or amide groups were characterized by the most favorable properties. The hardness and weight of the membranes changed the least in the case of copolymers consisting of many units with functional groups. Graphical abstract

Phytosterols are bioactive lipids susceptible to oxidation, particularly under thermal stress. Incorporation into liposomes may enhance their stability, while resveratrol-a natural antioxidant-could further limit thermal degradation. Stigmasterol esters, which contain fatty acid residues prone to oxidation, require additional characterization to understand their behavior under heating. Liposomes composed of dipalmitoylphosphatidylcholine (DPPC) were enriched with free stigmasterol (ST), stigmasteryl myristate (ME), or stigmasteryl oleate (OE), with or without resveratrol (RES). Liposomal systems were characterized using transmission electron microscopy, zeta potential, and hydrodynamic diameter analyses. Samples were heated at 60 °C and 180 °C for 8 h to evaluate stigmasterol degradation, oxyphytosterol (SOP) formation, and decomposition of fatty acid residues in the esters. Liposomes remained structurally stable at 60 °C but underwent marked alterations at 180 °C. ST formed the smallest particles, while ME and OE systems exhibited larger hydrodynamic diameters. Incorporation of resveratrol enhanced thermal and oxidative stability, reducing stigmasterol degradation (7.73-18.86% at 60 °C; 29.66-35.28% at 180 °C) and limiting SOP formation. Differences in the breakdown of myristic versus oleic acid residues highlighted the role of fatty acid type in determining thermal resistance. Resveratrol effectively improves the stability of liposomes containing stigmasterol or its esters and mitigates oxidative damage under thermal stress. Protective effects were particularly evident at moderate temperatures, indicating the potential of resveratrol-phytosterol liposomes as thermally stable delivery systems.

A large amount of graphene-related research is its use as a filler for polymer composites, including thin nanocomposite films. However, its use is limited by the need for large-scale methods to obtain high–quality filler, as well as its poor dispersion in the polymer matrix. This work presents polymer thin-film composites based on poly(vinyl chloride) (PVC) and graphene, whose surfaces were modified by curcuminoids. TGA, UV–vis, Raman spectroscopy, XPS, TEM, and SEM methods have confirmed the effectiveness of the graphene modification due to π–π interactions. The dispersion of graphene in the PVC solution was investigated by the turbidimetric method. SEM, AFM, and Raman spectroscopy methods evaluated the thin-film composite’s structure. The research showed significant improvements in terms of graphene’s dispersion (in solutions and PVC composites) following the application of curcuminoids. The best results were obtained for materials modified with compounds obtained from the extraction of the rhizome of Curcuma longa L. Modification of the graphene’s surface with these compounds also increased the thermal and chemical stability of PVC/graphene nanocomposites.

The authenticity assessment of edible oils is crucial to reassure consumers of product compliance. In this study, a new approach was taken to combining untargeted profiling by using differential scanning calorimetry (DSC) with chemometric methods in order to distinguish cold-pressed oils (flaxseed, camelina, hempseed) from refined oils (rapeseed, sunflower, soybean). The whole spectrum of DSC melting profiles was considered as a fingerprint of each oil. Flaxseed and hempseed oils exhibited four endothermic peaks, while three peaks with one exothermic event were detected for camelina seed oil. In the case of refined oils, two endothermic peaks were detected for rapeseed oil, three for sunflower oil and four for soybean oil. Thermodynamic parameters, such as peak temperature, peak heat flow and enthalpy, differed for each type of oil. Principal component analysis (PCA) and orthogonal partial least squares-discriminant analysis (OPLS-DA) were used for processing data consisting of the whole spectrum of heat flow variables of melting phase transition. PCA demonstrated a clear separation between refined and cold-pressed oils as well as six individual oils. The OPLS-DA showed a distinct classification in six classes according to the types of oils. High OPLS-DA coefficients including R2X(cum)=0.971, R2(cum)=0.916 and Q2X(cum)=0.887 indicated good fitness of the model for oil discrimination. Variables influence on projection (VIP) plot indicated the most significant variables of the heat flow values detected at temperatures around −29°C, −32°C, −14°C, −10°C, −24°C and −41°C for the differentiation of oils. The study ultimately demonstrated great potential of the untargeted approach of using the whole melting DSC profile with chemometrics for the discrimination of cold-pressed and refined oils.

In this work, a method to increase the dispersion of graphene (GN) in the matrix of rigid poly(vinyl chloride) (PVC) by using a natural plant extract from Curcuma longa L. (CE) is proposed. Currently, despite the increasing number of reports on the improvement of GN dispersion in PVC blends, still there is a need to find environmentally friendly and economical dispersion stabilizers. We proposed a stabilizer that can be easily obtained from a plant offering thermal stability and high effectiveness. PVC/GN nanocomposites stabilized with the proposed extract were investigated by SEM, AFM (structure), TGA, and Congo red test (thermal properties). Additionally, static and dynamic mechanical properties and electrical resistivity were measured. The use of CE as a graphene dispersant improved its dispersion in the PVC matrix, influenced tensile properties, increased the storage modulus and glass transition temperature, and extended the thermal stability time of nanocomposites. In this work, a CE extract is proposed as an efficient eco-friendly additive for the production of nanocomposites with an improved homogeneity of a nanofiller in the matrix and promising characteristics.

The cold-pressed oil from Japanese quince seeds (JQSO) is notable for its favorable fatty acid profile, low oxidation rate, and bioactive compounds like antioxidants, sterols, and carotenoids. This study offers a detailed molecular-level physical characterization of JQSO and its minor components using differential scanning calorimetry (DSC), Langmuir monolayer studies, and various spectroscopic methods, including UV–vis absorption, fluorescence, and FTIR. DSC analysis identified five peaks related to triglyceride (TG) fractions and provided insights into the melting and crystallization behavior of JQSO. The Langmuir monolayer studies revealed high compressibility, indicative of superior emulsification properties. Viscoelastic modulus measurements suggested strong intermolecular interactions, contributing to the oil’s resilience under stress—an attribute typical of oils high in saturated or monounsaturated fatty acids. Spectroscopic methods confirmed the presence of phenolic acids, tocopherols, carotenoids, and their derivatives. The total fluorescence spectra highlighted prominent peaks at 290 nm/330 nm and 360 nm/440 nm, while the total synchronous fluorescence spectra revealed key excitation–emission regions (10–50 nm/300 nm and 40–140 nm/360 nm), corroborating the presence of tocopherols, phenols, polyphenols, flavones, and carotenoids. No evidence of chlorophyll was detected. The ATR-FTIR spectra validated the presence of fatty acids and triacylglycerols, emphasizing a high degree of esterification and the dominance of unsaturated fatty acids in oil structures. The methods used provided the opportunity to perform a label-free, fast, and reliable determination of the properties of JQSO. The findings confirmed that crude, cold-pressed JQSO retains its valuable bioactive components, aligning with previous research on its chemical and physical properties.

Recent studies show that alpha-tocopheryl succinate (TS) exhibits selective toxicity against cancer cells. In this study, we investigated the effect of TS’s presence on the physico-chemical and structural properties of DPPC liposomes using fluorescence parameters (intensity, lifetime, and position of emission maximum) of 1-anilino-8-naphtalene sulphonate (ANS), differential scanning calorimetry (DSC) and zeta potential methods. Increasing the TS presence in the DPPC gel phase produced ANS fluorescence enhancement with a hypsochromic shift of the maximum. The zeta potential measurements show an increase in the negative surface charge and confirmed that this process is connected with the hydrophobic properties of dye, which becomes located deeper into the interphase region with a progressing membrane disorder. Temperature dependence studies showed that an increase in temperature increases the ANS fluorescence and shifts the ANS maximum emission from 464 to 475 nm indicating a shift from hydrophobic to a more aqueous environment. In the liquid crystalline phase, the quenching of ANS fluorescence occurs due to the increased accessibility of water to the ANS located in the glycerol region. The DSC results revealed that increasing the presence of TS led to the formation of multicomponent DSC traces, indicating the formation of intermediate structures during melting. The present results confirmed that TS embedded into the DPPC membrane led to its disruption due to destabilisation of its structure, which confirmed the measured biophysical parameters of the membrane.

Steady-state emission spectroscopy of 1-anilino-8- naphthalene sulfonate (ANS) and 1,6-diphenyl-1,3,5-hexatriene (DPH), fluorescence anisotropy, and DSC methods were used to characterize the interactions of the newly synthesized 1-carba-alpha-tocopherol (CT) with a 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) membrane. The DSC results showed significant perturbations in the DPPC structure for CT concentrations as low as 2 mol%. The main phase transition peak was broadened and shifted to lower temperatures in a concentration-dependent manner, and pretransition was abolished. Increasing CT concentrations induced the formation of new phases in the DPPC structure, leading to melting at lower temperatures and, finally, disruption of the ordered DPPC structure. Hydration and structural changes of the DPPC liposomes using ANS and DPH fluorescent probes, which are selectively located at different places in the bilayer, were studied. With the increased concentration of CT molecules in the DPPC liposomes, structural changes with the simultaneous formation of different phases of such mixture were observed. Temperature studies of such mixtures revealed a decrease in the temperature of the main phase transition and fluidization at decreasing temperatures related to increasing hydration in the bilayer. Contour plots obtained from concentration–temperature data with fluorescent probes allowed for identification of different phases, such as gel, ordered liquid, disordered liquid, and liquid crystalline phases. The CT molecule with a modified chromanol ring embedded in the bilayer led to H-bonding interactions, expelling water molecules from the interphase, thus introducing disorder and structural changes to the highly ordered gel phase.