Cellulose based Nano-Composites and Applications

Influence of cellulose nanomaterial dimensions on the crystalline structure and properties of thermoplastic starch composites.

A coherent standardization framework is essential for the industrial deployment of cellulose nanomaterials (CNMs). Although CNMs offer attractive properties for diverse industrial applications, their distinct morphological types—cellulose nanocrystals (CNCs), individualized cellulose nanofibrils (iCNFs), and entangled cellulose nanofibrils (eCNFs)—introduce morphological complexity that hinders reproducible quality evaluation. ISO has established terminology and several test method standards; however, testing standards remain limited for CNCs and iCNFs, and are still lacking for eCNFs, leaving a significant gap between material characterization and industrial use. This study proposes a structured framework that aligns terminology, test method, testing, and specification standards along the CNM industrialization pathway. The framework highlights the essential role of testing standards as the appropriate evaluation basis for CNMs at their present developmental stage, in contrast to specification standards suited to mature materials with clearly defined applications. A complementary scenario-based methodology is also introduced to support coherent and reproducible development of individual testing standards. By positioning existing ISO CNM standards within this pathway and clarifying the evaluative and bridging functions of testing standards, this study provides an industry-oriented foundation for reliable CNM quality assessment. The conceptual approach may also support standardization strategies for other bio-based materials in similarly early stages of industrialization.

Cellulose nanomaterials (CNs) are an emerging class of materials with numerous potential applications, including as additives or reinforcements for thermoplastics. Unfortunately, the preparation of CNs typically results in dilute, aqueous suspensions, and the lack of efficient water removal methods has hindered commercialization. However, water may also present opportunities for improving overall efficiencies if its potential is better understood and if it is better managed through the various stages of CN and composite production. Wet compounding represents one such possible opportunity by leveraging water’s ability to aid in CN dispersion, act as a transport medium for metering and feeding of CNs, plasticize some polymers, or potentially facilitate the preparation of CNs during compounding. However, there are also considerable challenges and much investigation remains. Here, we review various wet compounding approaches used in the preparation of cellulose nanocomposites as well as the related concepts of wet feeding and wet extrusion fibrillation of cellulose. We also discuss potential opportunities, remaining challenges, and research and development needs with the ultimate goal of developing a more integrated approach to cellulose nanocomposite preparation and a more sophisticated understanding of water’s role in the compounding process.

Applications of cellulose nanomaterials (CNMs) have attracted increasing attention in recent years. One conceivable path lies in their commercial applications for packaging, in which their barrier properties will play an important role in determining their competiveness with conventional materials. This review critically analyzes the performance of CNMs acting as a barrier against moisture and oxygen permeation in CNM films, CNM-coated polymers and papers, and CNM-reinforced polymer composites, gives some insights into remaining challenges, and brings an overall perspective of compositing CNMs with other materials to achieve balanced properties adequate for barrier packaging. In general, CNMs are a poor moisture barrier but excellent oxygen barrier in the dry state and are still good below 65% relative humidity. The addition of CNMs can improve the oxygen barrier of the resulting polymer composites; however, neat CNM coatings and films can afford better oxygen barrier properties than dispersed CNMs in coatings and nanocomposites. The morphology and surface functionality of CNMs can be tailored to maximize the barrier performance of materials comprising them. The higher the surface charge density is of CNMs, the better is the barrier performance of coated polymers. Like other oxygen barriers such as ethylene vinyl alcohol and cellophane, the moisture sensitivity and sealability of CNMs can be improved by sandwiching them with high moisture-resistant and sealable polymers such as a polyolefin. A multilayered structure with layers of CNMs providing oxygen resistance covered by other layers of polymers providing moisture resistance and sealability might be competitive in barrier packaging markets dominated by synthetic plastics.

In recent years, the research on nanocellulose composites with polymers has made significant contributions to the development of functional and sustainable materials. This review outlines the chemistry of the interaction between the nanocellulose and the polymer matrix, along with the extent of the reinforcement in their nanocomposites. In order to fabricate well-defined nanocomposites, the type of nanomaterial and the selection of the polymer matrix are always crucial from the viewpoint of polymer–filler compatibility for the desired reinforcement and specific application. In this review, recent articles on polymer/nanocellulose composites were taken into account to provide a clear understanding on how to use the surface functionalities of nanocellulose and to choose the polymer matrix in order to produce the nanocomposite. Here, we considered cellulose nanocrystal (CNC) and cellulose nanofiber (CNF) as the nanocellulosic materials. A brief discussion on their synthesis and properties was also incorporated. This review, overall, is a guide to help in designing polymer/nanocellulose composites through the utilization of nanocellulose properties and the selection of functional polymers, paving the way to specific polymer–filler interaction.

Cellulose nanomaterials are naturally occurring with unique structural, mechanical and optical properties. While the paper and packaging, automotive, personal care, construction, and textiles industries have recognized cellulose nanomaterials' potential, we suggest cellulose nanomaterials have great untapped potential in water treatment technologies. In this review, we gather evidence of cellulose nanomaterials' beneficial role in environmental remediation and membranes for water filtration, including their high surface area-to-volume ratio, low environmental impact, high strength, functionalizability, and sustainability. We make direct comparison between cellulose nanomaterials and carbon nanotubes (CNTs) in terms of physical and chemical properties, production costs, use and disposal in order to show the potential of cellulose nanomaterials as a sustainable replacement for CNTs in water treatment technologies. Finally, we comment on the need for improved communication and collaboration across the myriad industries invested in cellulose nanomaterials production and development to achieve an efficient means to commercialization.

The technological advancements in agriculture and food technology industry have created many controversial ethics and social responsibility areas. The aim of this paper is to discuss the past, present and potential future trends in ethics and corporate social responsibility in agriculture and food technology industry. It also seeks to identify the ethics and corporate social responsibility gap generated by the rapid technological advancements in this industry. The factors that need to be taken into account by corporate as a part of its ethics and social responsibility when introducing new technology were discussed in this paper. The discussion revealed that new technologies have generated great ethics and social responsibility. These concerns are in regard to consumers and workers health, environment, economic, over use of natural resources and the impact on future generation life. Based on this discussion it was established that in the current situation and with regard to the advancements in agriculture and food technology, the industry has ethical and social responsibility towards the general consumers. This paper reasons that corporations working in agriculture and food technology are required to actively consider their responsibility and adopt ethical and social responsibility policy. Moreover, this paper has predicted the future trends on light of the past and present technological advancements. Based on the discussion, the paper concluded that there is an ethical and social responsibility gap due to the advancements in agriculture and food technology. Thus, it is the responsibility of corporation to address this gap when evaluating new technology. The evaluation should consider several suitable means such as environmental impact analysis as well as social impact analysis. It was also concluded that the current risk assessment of genetically modified food has its limitation due to the availability of limited long term scientific evidence. In order to align the corporate practice with its ethics and social responsibility a list of recommendations were formulated by the authors. These recommendations included but not limited to: 1. The integration of consumer health impact with other relevant factors such as economical and environmental impacts; 2. Adequate labelling of genetically modified ingredient; 3. Adopting an ethic and social responsibility policy; 4. Implementation of post-marketing surveillance and monitoring strategy to assess the long term effects of genetically modified food on human health, and 5. The implementation of a suitable system to control the release of unauthorized genetically modified crops from research laboratories into the food chains and the environment. Key words: Agriculture, ethics, food technologies, genetically modified food.

A variety of chemicals are used in various stages of oil exploitation to ensure the normal progress of exploitation and improve the efficiency of oil recovery. However, most of the conventional petroleum-based chemicals are non-biodegradable, which will remain as wastes after applying, leading to serious environmental menace. In recent years, cellulose nanomaterials have attracted extensive interest due to their renewable and biodegradable features, as well as excellent chemical, mechanical, and rheological properties. This review comprehensively summarizes recent advances in exploring cellulose nanomaterials for oil exploration applications. Firstly, the preparation and properties of cellulose nanomaterials are briefly introduced. Then, the applications of cellulose nanomaterials in different petroleum exploitation processes, including drilling, cementing, and enhancing oil recovery are systematically discussed. Finally, the perspectives and challenges of cellulose nanomaterials for oil exploration applications are provided. It is expected that cellulose nanomaterials will be developed as promising oilfield chemicals for large scale application.

Cellulosic nanomaterials exhibit great potential in various applications due to their unique properties, abundant availability, and low production cost. Although cost effective to produce it is costly to ship, primarily due to the excess of water (>95 wt.%) in growth media necessary to produce the cellulosic nanomaterials. Therefore, a need has been identified by cellulosic material providers to develop energy-efficient, dewatering or drying of cellulosic nanomaterials, “as cellulosic nanomaterials are not economical to ship long distances while containing significant water content”. Moreover, the dewatered or dried cellulosic nanomaterials should be readily re-dispersed in water without any changes in its functional properties. Faraday Technology in collaboration with AVAPCO, answer this need by developing an economical manufacturing method and apparatus for electrochemical dewatering of cellulosic nanomaterials including cellulose nanocrystals (CNCs) and cellulose nanofibrils (CNFs). Specifically, our innovation is directed towards dewatering of CNCs and CNFs, not drying. AVAPCO has indicated that dewatering to 20-30 wt.% solids would be the end product for numerous applications such as cosmetics and paper processing. Using innovative reactor designs, we demonstrated the feasibility of a cost-effective, industrially viable, and energy efficient ElectroDewatering approach capable of generating 20 wt.% final solids, that was rehydrated under vortex and confirmed for re-dispersibility. Material properties (structure, particle size) were maintained by the dewatered cellulosic nanomaterials. Implementing sophisticated electric fields, we reduced energy use by 50% compared to conventional constant voltage approaches at similar or higher dewatering performance. Specifically, this talk will discuss the results of these advancements. Acknowledgements: The financial support of DOE Contract No. DE-SC0018787 is acknowledged.

The present study investigates the intricate relationships between the properties of cellulose nanomaterials (CNMs) and the lignocellulosic feedstocks from which they are derived. The starting pulps, consisting of eucalyptus, pine, hemp, and sisal commercial bleached pulps where characterized, and later subjected to TEMPO-mediated oxidation at several concentrations, followed by mechanical treatment in a high-pressure homogenizer. The resulting CNMs were extensively analyzed to assess carboxyl content, nanofibrillation yield, optical transmittance, and rheological and structural properties through methods including X-ray diffraction, X-ray photoelectron spectroscopy, solid-state 13C nuclear magnetic resonance, and sugar composition analysis post-acidic methanolysis. Despite the consistent processing conditions, the study reveals significant differences in the physicochemical and rheological behaviors of CNMs, strongly linked to the inherent properties of their respective feedstocks. These disparities highlight the pivotal influence of feedstock characteristics on the final attributes of CNMs, while most of the previous works linked these differences either to chemical or structural differences. The findings suggest that optimizing CNM properties for specific applications requires precise control over feedstock selection and processing parameters, underscoring the critical role of material origin in the development and application of advanced nanomaterials.

The transformative and versatile role of cellulose nanomaterials (CNMs) as an enabling technology in the preparation of multiscale mesostructured ceramics, with pore sizes in the meso- (2-50 nm) and macroporosity (above 50 nm) range with controlled porous architecture across the structure is explored. CNMs have revolutionized functional advanced materials concepts and technology by using natural resources to derive superb properties. Its unique chemical and physical properties have inspired its exploitation as a reinforcement agent, stimuli responsive tool, and templating agent mostly for biologic and polymeric materials, as well as for metals and ceramics. CNMs can act as a sacrificial filler templating agent, a surface modifier agent, and as an aid for shaping macrostructures into bulk samples. A deep knowledge of the synergistic interaction mechanisms between CNMs and ceramic particles to assemble them in solution and into solid structures is key to advance this technology, and to develop a predictive understanding of synthesis and processing mechanisms that relates morphology evolution, processing, and final physical properties. The potential ease of processing and versatility of CNMs for functional ceramic technology, intimately linked to the CNMs' nature and properties, will make a significant impact with respect to the current state of the art.

Nanocellulose has attracted substantial interest as a promising candidate for bio-nanocomposites due to its excellent physico-chemical properties such as high surface area, high mechanical strength and low density. The application of cellulosic nanoparticles for the fabrication of bio- and nanocomposites is a relatively new field of research. Cellulose micro- and nanofibres can be used as reinforcement in biocomposite materials as they provide higher mechanical, thermal and biodegradation properties to composite. In this chapter, we consider cellulose nanocrystals (CNCs) and cellulose nanofibres (CNFs) as the nanocellulosic materials. A brief discussion on their source and properties is also incorporated. Because of the numerous publications on cellulose nanocomposites, this chapter discusses the structure of different cellulose substrates and their different types of expedient properties. A comprehensive discussion on the gas barrier, thermal, mechanical, water absorption, permeability and crystallinity which are responsible for gaining so much interest towards these materials is also included. The chapter also discusses relatively new applications of nanocellulose, namely, water sorption and gas barrier functionality. The mechanism of the oxygen barrier and the effect of nanocellulose-based materials on different gas barrier properties are also discussed. This chapter, overall, is a guide to help in designing nanocellulose-based composites through the utilization of nanocellulose-specific properties and the selection of functional polymers, paving the way to a selection of specific cellulose nanoparticles depending on their property.

Chapter 9 - Structure/Function Relations of Chronic Wound Dressings and Emerging Concepts on the Interface of Nanocellulosic Sensors

Nanocellulose composites with enhanced mechanical and flame-retardant properties based on grafting of inorganic organic/multilayer core-shell matter - MSNs-TMSB/DA/TOCNF.

This review describes the recent advances in the production and application of cellulose nanomaterials. Cellulose nanomaterials (CNMs), especially cellulose nanocrystals and cellulose nanofibers, can be produced using different preparation processes resulting in materials with unique structures and physicochemical properties that are exploited in different fields such as, biomedical, sensors, in wastewater treatment, paper and board/packaging industry. These materials possess attractive properties such as large surface area, high tensile strength and stiffness, surface tailor-ability via hydroxyl groups and are renewable. This has been a driving force to produce these materials in industrial scale with several companies producing CNMs at tons-per-day scale. The recent developments in their production rate and their applications in various fields such as medical sector, environmental protection, energy harvesting/storage are comprehensively discussed in this review. We emphasize on the current trends and future remarks based on the production and applications of cellulose nanomaterials.