Recently, the advancements in energy storage and conversion have surfaced as a critical solution topic currently being discussed in various nations to accomplish a sustainable energy strategy that meets the increasing global energy demands. Therefore, several electrochemists are keen to propose the fabrication of next-generation devices that have boosted electrochemical performance as well as enhanced photochemical conversion efficiency. Polyaniline composite had been chosen for this contemporary study due to its tunable properties and multifunctionality. With a prominence on their practices in renewable energy supply, we have comprehensive topical progressions in research on accurate molecular design grounded on inorganic and organic fillers mixed with polyaniline to form its composite and novel procedures in this investigation. These mixed fillers transform polyaniline into binary and ternary composites by lowering the energy barrier, significantly enhancing the efficiency of next-generation energy supply systems. Wide determination is being reformed to enhance energy efficiency and the accountable usage of energy-active properties. This inclusion of fillers boosts redox reversibility, specific charge capacitance, and photo-conversion efficiency in the chain of polyaniline assembly. The review delivers a comparative scrutiny of multifunctional polyaniline composites, helping readers comprehend how the amalgamation of numerous fillers can enhance the electrochemical performance and photo-conversion efficiency that unlocks its potential in the fabrication of next-generation devices. Such pendant fillers linked to polyaniline assembly unlocked innovative skylines for investigators for sustainable energy resolution, owing to robust charge alteration with boosted efficiency compatible with supercapacitors and next-generation solar devices. This could turn out to be an upcoming transformation that assists administrators in sustaining command and is an integrated approach for satisfying real-world requirements.
Polylactic acid (PLA), a thermoplastic aliphatic polyester derived from renewable resources has garnered considerable attention due to its biodegradability, biocompatibility and favorable processing characteristics. However, inherent limitations such as brittleness, low thermal resistance and suboptimal mechanical performance restrict its utility in high-demand applications. This review critically evaluates recent advancements in reinforcing PLA with a broad spectrum of additives including natural fibers, nanocellulose, inorganic oxides and bioactive herbal/fungal powders. Each reinforcement modality is analyzed in terms of its effect on tensile, flexural and impact properties along with processing compatibility under extrusion, injection molding, compression molding and 3D/4D printing. The synergistic enhancements in stiffness, toughness, biofunctionality and shape-memory response are emphasized. Quantitative comparisons highlight that optimized filler loading typically 1–5 wt
This review addresses current trends in the development of approaches to the modification of epoxy systems with polymers. The use of thermoplastics inert to the components of epoxy systems, including structural thermoplastics, block copolymers, and dendritic and hyperbranched polymers for modifying epoxy resins is considered, as well as combined modification with thermoplastics and fillers. In addition, the review highlights the use of reactive polymers for modifying epoxy systems; these compounds can participate in the curing reaction of epoxy resins under certain conditions, incorporating into the structure of the resulting crosslinked material; the potential advantages of such modifiers are discussed. Particular attention is given to reactive polymers and copolymers containing anhydride groups.
The systematic analytical study of the previously developed nonlinear constitutive equation (CE) for the shear flow of thixotropic viscoelastic-plastic media, which accounts for the interplay of deformation and structural evolution, is continued. For an arbitrary set of six material parameters and an increasing material function governing the model, the basic properties of families of stress relaxation curves (RCs) generated by the CE at instantaneous loading and under ramp loading (taking into account a rise time to a specified strain level), as well as relaxation modulus, structural evolution features and relaxation time under these loading conditions are analytically studied. The analysis focuses on the ramp RCs dependence on material parameters and function of the CE and on a rise time and strain level. The unusual (but observed in tests) properties of RCs arising as a result of structural changes, compared to typical RCs of structurally stable materials (test RCs and RCs generated by linear or nonlinear CEs), are studied. This includes the dependence of RCs and the relaxation modulus on strain level and rise time, as well as the emergence of new relaxation scenarios compared to those observed under step loading. It is proven that for any material parameters and CE function, all ramp RCs decrease with time and have the common zero asymptote. However, RC convexity and increase in RCs family with strain level may be broken due to sufficiently rapid structural changes. This behavior contrasts with experimental RCs for structurally stable materials and RC families generated by the Boltzmann-Volterra viscoelastic CE. The studied CE can describe both convex downward RCs and RCs with inflection points, as well as the growth of RCs and the relaxation modulus with strain level, including the non-monotonic dependence of relaxation curve families on strain level. The initial deformation stage (loading history) significantly affects expression of these effects and the evolution of the relaxation time of the model. It is shown that a high strain rate at the initial stage may induce too high stress in a material and rapid structure break, which will change the material properties drastically, accelerate stress relaxation phase and make RCs with different strain levels to intersect and intertwine. Conversely, a gradual and lasting strain increase to the target level can distort the expected RC properties if the material is structurally mobile and the initial structuredness is significantly less than the equilibrium value. At the initial stage, the material may have time to increase its structuredness (e.g., during processes like gelation or resin curing in composites or 3D printing of photopolymers), which leads to a slowdown of further stress relaxation. The article demonstrates all these effects, which are related to the influence of the initial loading stage, or nonlinearity, or the structural evolution. It explains the possible reasons for families of RCs with unusual properties observed in some experimental studies. It is shown that ignoring the influence of initial loading stage and the possibility of structural changes in a material during deformation may lead to incorrect interpretations of test data and observed phenomena.
The work studies self-association behavior of comb-like macromolecules with hydrophobic side chains depending on the distribution of the side chains grafting points, molar mass and the length of side chains. It is shown that the distribution of the side chains grafting points determines the morphology of the globules: sufficiently long macromolecules with a regular grafting points distribution form multidomain globules, while the globules of those with random distribution have elongated or necklace-like morphology. The change in the shape of the globule as the length of the macromolecule increases is reflected by the exponent in the scaling dependencies of the macromolecule sizes on its degree of polymerization. While for short chains this exponent corresponds to the generally accepted 1/3 for compact spherical particles, for long chains this exponent is close to that for elongated objects. Self-association shifts to the area of poor solvent with the decrease in side chains length. The indicator of these associative interactions is the Kraemer parameter. The conclusions of the study are based on the analysis of the experimental literature data, including the works by the authors, as well as novel, previously unpublished experiments and supported by molecular dynamics computer simulation. The experiment compares the hydrodynamic properties of random amphiphilic copolymers of N-methyl-N-vinylacetamide and N-methyl-N-vinylamine iodide (with different lengths of the hydrophobic side pendants (–C12H25, –C10H21, –C8H17, –C6H13)) and a homopolymer sodium polystyrene-4-sulfonate. Viscometric studies of copolymers of N-methyl-N-vinylacetamide and N-methyl-N-vinylamine iodide were carried out in a pure water, water-salt solvent NaCl of different quality.
