Chemical and Materials Sciences: Research Findings Vol. 9

Optimization of Self Healing Polyether–Polythioether Networks via Factorial Design in Epoxy/Thiol–Ene Photopolymerizations

Ricardo Acosta Ortiz — 2026-09-26

Aim: The study aims to optimize the self-healing behaviour of polyether–polythioether co-networks containing dynamic disulfide bonds produced via epoxy/thiol–ene photopolymerisation.

Study Design: A factorial design of experiments (DoE) evaluating the effects of thiol–ene system (TES) concentration, tributylphosphine (TBP) concentration, and healing temperature.

Methodology: Self-healing functionality was introduced by synthesizing a disulfide–thiol oligomer, which was subsequently incorporated into a photocurable formulation that included a bio-based epoxy resin, a tetraallyl ditertiary amine curing agent, and a photoinitiator. After photopolymerization, the resulting specimens were cut into two halves and subjected to thermal treatment to promote rejoining. A factorial DoE was performed by varying TES concentration, TBP concentration, and temperature. Healing time, defined as the time required for the two halves of the specimen to fully rejoin chemically, was recorded for each experimental condition. Statistical analysis was carried out using ANOVA.

Results: Healing efficiency exhibited a strong dependence on experimental factors. Higher temperatures and increased TBP concentrations consistently led to shorter healing times, with the fastest healing (5 min) achieved at 80 °C under elevated TBP levels. ANOVA confirmed that the model accurately described the experimental data, with a highly significant overall p-value (0.015), indicating that the selected factors collectively accounted for most of the variability in healing time. The linear component of the model contributed the largest share of variance (SS = 2067.38), and its associated p-value (0.01) demonstrated that the primary effects of the factors were statistically significant.

Conclusion: Optimal healing conditions were identified as 40 mol% TES, 1 mol% TBP, and a temperature of 80 °C, under which complete healing was achieved in only 5 minutes.

Nanotechnology-Enabled Precision Agrochemical Delivery: Stimuli-Responsive Nanocarriers, Target Release Mechanisms and Soil Fate

Anil Kumar — 2026-09-26

Nano-enabled agrochemical delivery is increasingly framed as a route to improve pesticide and fertiliser efficiency while reducing off-target losses, yet the label “precision” often obscures major differences among sustained-release formulations, biologically targeted carriers and truly stimuli-responsive systems. This critical narrative review evaluates how nanocarrier architecture, trigger chemistry, release mechanisms, plant-interface behaviour and soil fate interact to determine whether precision delivery is achieved in agronomically realistic settings. Literature published from 1 January 2012 to 4 July 2026 was examined, with older material retained only when conceptually necessary. The strongest mechanistic evidence concerns pH-, enzyme-, light-, temperature- and ion-responsive systems, including mesoporous silica, biodegradable polymers, metal–organic frameworks, carbon-based materials, hydrogels and hybrid carriers. Across these platforms, apparent gains in loading, protection, adhesion, rainfastness, plant translocation or bioactivity are frequently demonstrated under controlled conditions, but trigger specificity and exposure reduction are less consistently established in field-relevant matrices. A central distinction emerges between controlled release and precision release: slowing diffusion alone does not demonstrate spatial or temporal targeting, and reduced peak exposure can coexist with prolonged environmental persistence. Soil studies further show that carrier–active ingredient interactions can alter sorption, dissipation, mobility and organismal exposure, while aggregation, dissolution, organic matter and ionic composition can change the carrier itself. Evidence for effects on soil microbial communities and non-target organisms remains formulation-specific and too heterogeneous to support general safety claims. The review therefore argues for a design logic based on minimal sufficient complexity, quantitative trigger validation in crop–pest microenvironments, parallel tracking of carrier and cargo, and comparative testing against appropriate conventional formulations. Progress towards credible precision agrochemical delivery will depend less on adding responsive functions than on demonstrating that those functions remain selective, scalable and environmentally interpretable from application through degradation.

Core Principles and Thermodynamic Functions in Classical Chemical Thermodynamics: A Critical Narrative Review

Riffat Basharat — 2026-09-26

Classical chemical thermodynamics remains the interpretive backbone of physical chemistry, chemical engineering, geochemistry and materials science, yet the discipline continues to carry unresolved conceptual and operational tensions that are rarely examined together. This review critically evaluates the core principles of the classical framework and the thermodynamic functions built upon them, tracing how foundational statements of the laws, the interpretation of entropy, the Legendre structure of the state functions, the practices of measurement and data evaluation, and the predictive models derived from them either reinforce or undermine one another. Literature was identified through open scholarly indexes and citation searching, appraised for methodological adequacy and conceptual contribution rather than citation count alone, and synthesised thematically around mechanisms, controversies and methodological weaknesses. Five findings emerge. Axiomatic reconstructions have clarified what the second law does and does not assert, but the version of the law transmitted through chemical practice remains logically weaker than the version defended in the foundational literature. Entropy is supported by several mutually incompatible interpretations, and the disagreement is substantive rather than merely verbal, as the long-running dispute over system entropy against total entropy demonstrates. The thermodynamic functions are formally secure yet operationally ambiguous, with standard states, activity conventions and the reaction Gibbs energy repeatedly misapplied in both research and instructional settings. Numerical thermodynamics depends on measurement and data-evaluation practices whose uncertainty structure is frequently under-reported, weakening the apparent precision of derived quantities. The boundaries of the classical framework, at small system sizes, under strong fluctuations and far from equilibrium, are now well characterised, but their implications for routine chemical practice remain largely unabsorbed. Confidence is strongest for the formal structure and the metrological foundations, and weakest for interpretive claims about entropy and for the transferability of classical reasoning to nanoscale and driven chemical systems.