Sustainable adsorbent frameworks based on bio-resourced materials and biodegradable polymers in selective phosphate removal for waste-water remediation.

Phosphorus to an optimum extent is an essential nutrient for all living organisms and its scarcity may cause food security, and environmental preservation issues vis-à-vis agroeconomic hurdles. Undesirably excess phosphorus intensifies the eutrophication problem in non-marine water bodies and disrupts the natural nutrient balance of the ecosystem. To overcome such dichotomy, biodegradable polymer-based adsorbents have emerged as a cost-effective and implementable approach in striking a "desired optimum-undesired excess" balance pertaining to phosphate in a sustainable manner. So far, the reports on adopting such adsorbent-approach for wastewater remediation remained largely scattered, unstructured, and poorly correlated. In this background, the contextual review comprehensively discusses the current state-of-the-art in utilizing biodegradable polymeric frameworks as an adsorbent system for phosphate removal and its efficient recovery from the aquatic ecosystem, while highlighting their characteristics-specific functional efficiency vis-à-vis easiness of synthetic and commercial viability. The overview further delves into the sources and environmental ramifications of excessive phosphorus in water bodies and associated mechanistic pathways of phosphorus removal via adsorption, precipitation, and membrane filtration enabled by biodegradable (natural and synthetic) polymeric substrates. Finally, functionality optimization, degradability tuning, and adsorption selectivity of biodegradable polymers are highlighted, while aiming to strike a balance in "removal-recovery-reuse" dynamics of phosphate. Thus, the current review not only paves the way for future exploration of biodegradable polymers in sustainable cost-effective adsorbents for phosphorus removal but also can serve as a guide for researchers dealing with this critical issue.

Advances in design of polymer brush functionalized inorganic nanomaterials and their applications in biomedical arena.

Grafting of polymer brush (assembly of polymer chains tethered to the substrate by one end) is emerging as one of the most viable approach to alter the surface of inorganic nanomaterials. Inorganic nanomaterials despite their intrinsic functional superiority, their applications remain restricted due to their incompatibility with organic or biological moieties vis-à-vis agglomeration issues. To overcome such a shortcoming, polymer brush modified surfaces of inorganic nanomaterials have lately proved to be of immense potential. For example, polymer brush-modified inorganic nanomaterials can act as efficient substrates/platforms in biomedical applications, ranging from drug-delivery to protein-array due to their integrated advantages such as amphiphilicity, stimuli responsiveness, enhanced biocompatibility, and so on. In this review, the current state of the art related to polymer brush-modified inorganic nanomaterials focusing, not only, on their synthetic strategies and applications in biomedical field but also the architectural influence of polymer brushes on the responsiveness properties of modified nanomaterials have comprehensively been discussed and its associated future perspective is also presented. This article is categorized under: Diagnostic Tools > In Vivo Nanodiagnostics and Imaging Therapeutic Approaches and Drug Discovery > Emerging Technologies Nanotechnology Approaches to Biology > Nanoscale Systems in Biology.

Ultratoughening of Biobased Polyamide 410.

The microstructural, thermomechanical, and quasistatic mechanical properties of biobased polyamide 410 (PA410)/poly(octane-co-ethylene)-g-maleic anhydride (POE-g-MA) blends with the impact toughener in the composition range of 0-20 wt % have been investigated, with an aim to overcome the poor notch and strain sensitivity of PA410. The crystallinity of the blends obtained from enthalpic measurements and initial degradation temperature indicating thermal stability remained mostly unaffected. A remarkably substantial increase, i.e., ∼15-fold enhancement, in the impact strength of the PA410/POE-g-MA blends leading to ultratoughening of PA410 accompanied by a significant increase in tensile strain at breaking is achieved though the elastic modulus (E) and yield strength (σ) decreased with impact modifier content. Thermomechanical analysis revealed a broadening in the loss tangent peak in the temperature range of ∼-50 to -30 °C corresponding to the POE phase, whereas the loss tangent peak corresponding to the PA410 phase stayed unaffected. Conventional theoretical models such as the rule of mixture and foam model were used to analyze the micromechanics of low-strain (<1%) mechanical response (E), and Nikolais-Narkis model and Isahi-Cohen models, for high-strain (>2%) mechanical response (σ). The interdependence of impact toughness, ductility ratio, and domain size of the dispersed rubber phase in the PA410/POE-g-MA blends could successfully be established vis-à-vis the mechanistic role of interparticle distance. Scanning electron microscopy showing domain coalescence of the soft elastomeric POE phase thus reiterated the pivotal role of interdomain distance and domain size in influencing the toughening mechanism of PA410/POE-g-MA blends. The qualitative phase distribution attributes based on atomic force microscopy remained in sync with quantitative parameters, such as domain size, hence reaffirming the mechanism behind ultratoughening of PA410 by POE.