Nanocellulose, including cellulose nanofibers (CNFs), cellulose nanocrystals (CNCs), and bacterial nanocellulose (BNC), represents a promising class of bio-based nanomaterials derived from natural sources. These materials, derived from plant-based cellulose, are characterized by exceptional mechanical strength, high surface area, biodegradability, and the ability to form stable nanoparticle networks, making them suitable for use in composites, biomedicine, electronics, and many other fields. In this review, we present the latest advancements in the production of nanocellulose, including preparation technologies and methods for chemical and physical modifications to enhance the performance of these materials. We also discuss various applications, such as its use in nanocomposites, sustainable packaging materials, flexible electronic devices, and as a support for biological media. Additionally, the challenges and opportunities related to the scalability of production and their integration into industries with growing economic and ecological demands are explored. The review provides a comprehensive overview of the potential of nanocellulose, highlighting its importance in the context of emerging technologies and sustainability.

The evolution from conventional to modern agricultural practices, characterized by Agriculture 4.0 principles such as the application of innovative materials, smart water, and nutrition management, addresses the present-day challenges of food supply. In this context, polymer hydrogels have become a promising material for enhancing agricultural productivity due to their ability to retain and then release water, which can help alleviate the need for frequent irrigation in dryland environments. Furthermore, the controlled release of fertilizers by the hydrogels decreases chemical overdosing risks and the environmental impact associated with the use of agrochemicals. The potential of polymer hydrogels in sustainable agriculture and farming and their impact on soil quality is revealed by their ability to deliver nutritional and protective active ingredients. Thus, the impact of hydrogels on plant growth, development, and yield was discussed. The question of which hydrogels are more suitable for agriculture—natural or synthetic—is debatable, as both have their merits and drawbacks. An analysis of polymer hydrogel life cycles in terms of their initial material has shown the advantage of bio-based hydrogels, such as cellulose, lignin, starch, alginate, chitosan, and their derivatives and hybrids, aligning with sustainable practices and reducing dependence on non-renewable resources.

This paper provides a solid foundation for understanding the synthesis, properties, and applications of cellulose-based gels. It effectively showcases the potential of these gels in diverse applications, particularly in biomedicine, and highlights key synthesis methods and properties. However, to push the field forward, future research should address the gaps in understanding the environmental impact, mechanical stability, and scalability of cellulose-based gels, while also considering how to overcome barriers to their industrial use. This will ultimately allow for the realization of cellulose-based gels in large-scale, sustainable applications.

The rational design of functional and sustainable polymers is central to addressing global environmental challenges. In this context, unmodified lignin derived from Sarkanda grass (Tripidium bengalense), an abundant agro-industrial lignocellulosic byproduct, was systematically investigated as a natural polymeric adsorbent for the remediation of aqueous media contaminated with heavy metals. The study evaluates lignin’s behavior toward nine metal(loid) ions: arsenic, cadmium, chromium, cobalt, copper, iron, nickel, lead, and zinc. Adsorption performance was systematically investigated under static batch conditions, optimizing key parameters, with equilibrium and kinetic data modeled using established isotherms and rate equations. Surface characterization and seed germination bioassays provided supporting evidence. Unmodified Sarkanda grass lignin demonstrated effective adsorption, exhibiting a clear preference for Cu(II) followed by other divalent cations, with lower capacities for As(III) and Cr(VI). Adsorption kinetics consistently followed a pseudo-second-order model, indicating chemisorption as the dominant mechanism. Thermodynamic studies revealed spontaneous and endothermic processes. Bioassays confirmed significant reduction in aqueous toxicity and strong metal sequestration. This work positions unmodified Sarkanda grass lignin as a bio-based, low-cost polymer platform for emerging water treatment technologies, contributing to circular bioeconomy goals and highlighting the potential of natural polymers in sustainable materials design.

Heavy metals are pollutants that pose a risk to living systems due to their high toxicity and ability to accumulate and contaminate. This study proposes an alternative approach to the static adsorption of Ni(II) from aqueous media using Sarkanda grass lignin crystals, the non-cellulosic aromatic component of biomass, as an adsorbent substrate. To determine the best experimental conditions, we conducted tests on several parameters, including the initial and adsorbent solution pH, the concentration of Ni(II) in the aqueous solution, the amount of adsorbent used, and the contact time at the interface. The lignin’s adsorption capacity was evaluated using the Freundlich and Langmuir models to establish equilibrium conditions. The Lagergren I and Ho–McKay II kinetic models were used to determine the adsorption mechanism based on surface analyses and biological parameters such as the number of germinated seeds, energy, and germination capacity in wheat caryopses (variety Glosa) incorporated in the contaminated lignin and in the filtrates resulting from phase separation. The results suggest that Sarkanda grass lignin is effective in adsorbing Ni(II) from aqueous media, particularly in terms of adsorbent/adsorbate dosage and interfacial contact time.

Solid state Cross-Polarization/Magic-Angle-Spinning ¹³C CP/MAS Nuclear Magnetic Resonance (NMR) spectra were obtained for cellulose and α-cellulose isolated from rapeseed stalks. This study provides the first characterization of the rapeseed stalk cellulose, revealing that native cellulose occurs as cellulose I allomorph, while α-cellulose exhibits distinct crystalline structures similar to those found in cellulose II. Additionally, Fourier Transform Infrared (FTIR) spectroscopy, Scanning Electron Microscopy (SEM), and Energy-Dispersive X-ray Microanalysis (EDX) were employed to further investigate and unveil the structural properties of cellulose extracted from rapeseed stalks. These complementary techniques offered a more comprehensive understanding of the cellulose morphology, crystallinity, and chemical composition, providing valuable insights into the potential utilization of rapeseed stalks as a renewable biomass resource for various industrial applications.