Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

Cellulose nanocrystals and cellulose nanofibrils based hydrogels for biomedical applications.

Over the past few years, nanocellulose (NC), cellulose in the form of nanostructures, has been proved to be one of the most prominent green materials of modern times. NC materials have gained growing interests owing to their attractive and excellent characteristics such as abundance, high aspect ratio, better mechanical properties, renewability, and biocompatibility. The abundant hydroxyl functional groups allow a wide range of functionalizations via chemical reactions, leading to developing various materials with tunable features. In this review, recent advances in the preparation, modification, and emerging application of nanocellulose, especially cellulose nanocrystals (CNCs), are described and discussed based on the analysis of the latest investigations (particularly for the reports of the past 3 years). We start with a concise background of cellulose, its structural organization as well as the nomenclature of cellulose nanomaterials for beginners in this field. Then, different experimental procedures for the production of nanocelluloses, their properties, and functionalization approaches were elaborated. Furthermore, a number of recent and emerging uses of nanocellulose in nanocomposites, Pickering emulsifiers, wood adhesives, wastewater treatment, as well as in new evolving biomedical applications are presented. Finally, the challenges and opportunities of NC-based emerging materials are discussed.

/pdf/nanocellulose-from-fundamentals-to-advanced-applications-ecdehj4ngu.pdf

Nanocellulose: From Fundamentals to Advanced Applications

The rapid development of modern industry and excessive consumption of petroleum-based polymers have triggered a double crisis presenting a shortage of nonrenewable resources and environmental pollution However, this has provided an opportunity to stimulate researchers to harness native biobased materials for novel advanced materials and applications Nanocellulose-based aerogels, using abundant and sustainable cellulose as raw material, present a third-generation of aerogels that combine traditional aerogels with high porosity and large specific surface area, as well as the excellent properties of cellulose itself Currently, nanocellulose aerogels provide a highly attention-catching platform for a wide range of functional applications in various fields, eg, adsorption, separation, energy storage, thermal insulation, electromagnetic interference shielding, and biomedical applications Here, the preparation methods, modification strategies, composite fabrications, and further applications of nanocellulose aerogels are summarized, with additional discussions regarding the prospects and potential challenges in future development

https://onlinelibrary.wiley.com/doi/pdf/10.1002/adma.202005569

Recent Progress on Nanocellulose Aerogels: Preparation, Modification, Composite Fabrication, Applications

High-strength petroleum-based materials like plastics have been widely used in various fields, but their nonbiodegradability has caused serious pollution problems. Cellulose, as the most abundant sustainable polymer, has a great chance to act as the ideal substitute for plastics due to its low cost, wide availability, biodegradability, etc. Herein, the recent achievements for developing cellulose "green" solvents and regenerated cellulose materials with high strength via the "bottom-up" route are presented. Cellulose can be regenerated to produce films/membranes, hydrogels/aerogels, filaments/fibers, microspheres/beads, bioplastics, etc., which show potential applications in textiles, biomedicine, energy storage, packaging, etc. Importantly, these cellulose-based materials can be biodegraded in soil and oceans, reducing environmental pollution. The cellulose solvents, dissolving mechanism, and strategies for constructing the regenerated cellulose functional materials with high strength and performances, together with the current achievements and urgent challenges are summarized, and some perspectives are also proposed. The near future will be an exciting era for high-strength biodegradable and renewable materials. The hope is that many environmentally friendly materials with good properties and low cost will be produced for commercial use, which will be beneficial for sustainable development in the world.

Recent Progress in High-Strength and Robust Regenerated Cellulose Materials

Nanocellulose nanocomposite hydrogels: technological and environmental issues

The objective of this work is to obtain thermoplastic starch, polymer biocomposites and nanobiocomposites using agro-industrial waste generated in mango processing, and characterize the obtained materials. The starch extraction from the kernels of mango pits showed a good yield and the obtained starch had high purity.The results obtained characterizing the fibers and cellulose nanowhiskers, from the husk of the mango seed, proved the effectiveness of chemical treatment removing the amorphous constituents (hemicellulose and lignin).The polymer biocomposites and nanobiocomposites were obtained and the TPS mango starch showed satisfactory results of mechanical and thermal properties, when compared with TPS corn starch materials with the same composition. It is concluded that the waste generated in the agro-industrial processing of mangos showed a potential source for biodegradable materials production

https://repositorio.ufrn.br/bitstream/123456789/41516/1/PolymerBiocomposites_ITO_2014.pdf

Polymer Biocomposites and Nanobiocomposites Obtained from Mango Seeds

Cellulose nanocrystals-reinforced core-shell hydrogels for sustained release of fertilizer and water retention.

This work aimed to study the use of cellulose nanofibers (CNFs) from coir husk fibers to develop nanocomposite hydrogels. Cellulose and lignin were obtained from coir husk using the steam explosion pretreatment, followed by alkaline-ethanol-water pretreatment and bleaching process. CNFs from coir husk fibers were obtained using a high-speed blender on cellulose pulp previously oxidized with 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO). Poly(N,N-dimethylacrylamide) (PDMA) was used as a matrix material to produce novel nanocomposite hydrogels reinforced with CNFs by a facile synthesis method. The compression modulus of PDMA/CNF hydrogels increased significantly when compared to PDMA hydrogel. The water-retention and nitrogen (N), phosphorous (P), and potassium (K) (NPK) fertilizer release studies indicated that the addition of CNFs considerably improved the water-retention capacity but reduced the nutrient loading capacity of the hydrogel. All the prepared nanocomposite hydrogels had significantly improved mechanical performance. Our study provides a facile and green route to produce CNFs and lignin. Furthermore, nanocomposite hydrogels with tunable properties for potential agriculture applications were prepared by homogeneously dispersing cellulose nanoparticles in PDMA.

Development of an integrated process to produce CNFs and lignin and its potential applications for agrochemical delivery

/pdf/obtencao-e-caracterizacao-de-gelatina-de-pele-de-tilapia-3bgr4ql9er.pdf

Yana L. Nunes

Papers

Nanocellulose nanocomposite hydrogels: technological and environmental issues

Polymer Biocomposites and Nanobiocomposites Obtained from Mango Seeds

Cellulose nanocrystals-reinforced core-shell hydrogels for sustained release of fertilizer and water retention.

Development of an integrated process to produce CNFs and lignin and its potential applications for agrochemical delivery

Obtenção e caracterização de gelatina de pele de tilápia.