scholarly journals All-Cellulose Composites: A Review of Recent Studies on Structure, Properties and Applications

Molecules ◽  
2020 ◽  
Vol 25 (12) ◽  
pp. 2836
Author(s):  
Behnaz Baghaei ◽  
Mikael Skrifvars

Nowadays, there is greater demand for greener materials in societies due to environmental consciousness, depleting fossil fuels and growing ecological concerns. Within the foreseeable future, industries and suppliers will be required to be more aware of challenges faced due to the availability of resources and use more sustainable and renewable raw materials. In this context, cellulose can be expected to become a vital resource for materials owing to its abundance, versatility as a biopolymer, several different forms and potential applications. Thus, all-cellulose composites (ACCs) have gained significant research interest in recent years. ACC is a class of biocomposites in which the matrix is a dissolved and regenerated cellulose, while the reinforcement is undissolved or partly dissolved cellulose. This review paper is intended to provide a brief outline of works that cover recent progress in the manufacturing and processing techniques for ACCs, various cellulose sources, solvents and antisolvents, as well as their properties.

Química Nova ◽  
2021 ◽  
Author(s):  
Lucas Santos ◽  
Gabrielle Fraga ◽  
Danilo Pontes ◽  
Leila Campos ◽  
Luiz Pontes ◽  
...  

Levulinic acid is a reactive polar organic compound deemed as a building block for several products with relevant applications, replacing traditional substances in the petrochemical industry. Considered a platform molecule, levulinic acid is industrially produced from the acid hydrolysis of biomass – mainly plant-based – using hydrochloric or sulfuric acid in homogenous catalysis. However, considering the World Market for levulinic acid is expected to reach US$ 71.9 million in 2027, growing annually at 14.1%, and its applications in agriculture, pharmaceuticals, plasticizers, cosmetics, and food additives, the development of alternative production processes is sought. Hence, a survey was performed on publications considering the alternatives for biomass-based levulinic acid production processes: I) alternative homogenous catalysts to avoid using noble materials in the reactor; II) heterogeneous catalysis to facilitate and reduce the catalyst’s separation and recovery costs; III) ionic liquids, exploiting their high solvency, stability, and catalytic capacity. Additionally, biomass alternatives for obtaining levulinic acid are presented, showing that other agricultural residues and animal biomass options are being considered, targeting process flexibilization while reducing costs and producing derivatives at more competitive prices. Thus, it can be stated that levulinic acid is an important platform molecule for biorefineries’ economics, replacing fossil fuels with renewable raw materials.


2018 ◽  
Vol 48 (1) ◽  
pp. 191-222
Author(s):  
Anna Turlej ◽  
Marta Skolniak

Abstract The development of the commercial air carriers market causes an increase in the aviation fuel consumption and the air pollution. There are intensive works in order to invent the possibility of supplying the aviation engines with biofuels. The hydrogen gas is needed for technological processes to obtain the synthetic biocomponents from biomass, which met the quality standards for fuels and aviation fuels. Pure hydrogen gas is scarce in the Earth’s atmosphere and has to be derived from petroleum products. Its acquisition currently requires the processing of petroleum-based matter. The whole world is looking for easy, cheap and safe ways of producing hydrogen from a variety of renewable raw materials, that are an alternative to fossil fuels. The article shows the technological potential of experimental methods for hydrogen production from ethanol produced from biodegradable waste, which is widely considered as a renewable and environmentally friendly resource.


Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 407
Author(s):  
Eulalia Gliscinska ◽  
Javier Perez de Amezaga ◽  
Marina Michalak ◽  
Izabella Krucinska

This article presents thermoplastic sound-absorbing composites manufactured on the basis of renewable raw materials. Both the reinforcing material and the matrix material were biodegradable and used in the form of fibers. In order to mix flax fibers with polylactide fibers, the fleece was fabricated with a mechanical system and then needle-punched. The sound absorption of composites obtained from a multilayer structure of nonwovens pressed at different conditions was investigated. The sound absorption coefficient in the frequency ranging from 500 Hz to 6400 Hz was determined using a Kundt tube. The tests were performed for flat composites with various structures, profiled composites, and composite/pre-pressed nonwoven systems. Profiling the composite plate by convexity/concavity has a positive effect on its sound absorption. It is also important to arrange the plate with the appropriate structure for the incident sound wave. For the composite layer with an added pre-pressed nonwoven layer, a greater increase in sound absorption occurs for the system when a rigid composite layer is located on the side of the incident sound wave. The addition of successive nonwoven layers not only increases the absorption but also extends the maximum absorption range from the highest frequencies towards the lower frequencies.


Nanoscale ◽  
2015 ◽  
Vol 7 (42) ◽  
pp. 17957-17963 ◽  
Author(s):  
Quanling Yang ◽  
Tsuguyuki Saito ◽  
Lars A. Berglund ◽  
Akira Isogai

Transparent all-cellulose composites prepared from cellulose nanofibrils and regenerated cellulose exhibit high mechanical strength, stiffness, thermal stability, and oxygen barrier properties with only 1% cellulose nanofibril content, resulting from the nano-reinforcement mechanism and nanofibril-induced crystallization of cellulose molecules in the matrix.


2020 ◽  
pp. 48-55
Author(s):  
M.E. Sharanda ◽  
◽  
E.A. Bondarenko ◽  

Ethylene glycol and propylene glycol are important representatives of polyols. On an industrial scale, they are obtained from petrochemical raw materials. Within a decade, significant efforts were made for the producing of polyols from biologically renewable raw materials - carbohydrates. The general trend for carbohydrate hydrogenolysis includes application of liquid-phase process with the use of modified metal-oxide catalysts, at 120-120 ° C and pressure of 3MPa or above. So high pressure is used for the reason to increase hydrogen solubility, and also due to the high partial pressure of low boiling solvents. We supposed that usage of high boiling solvents could allow hydrogenolysis to be performed at the lower pressure. Ethylene glycol and propylene glycol are of particular interest as such kind of solvent since they are both the main products of glucose hydrogenolysis. In this work, the process of hydrogenolysis of glucose and fructose over Cu / MgO-ZrO2 catalyst have been studied at temperature range of 160-200 °C and a pressure of 0.1-0.3 MPa in a flow reactor. The solvents were simultaneously the target products of the reaction - ethylene glycol and / or propylene glycol. Gas chromatography and 13C NMR were used for the reaction products identification. It was found that the solubility of glucose in propylene glycol is 21 % by weight, and in ethylene glycol 62% by weight. It was pointed out that the process of hydrogenolysis can take place at a pressure close to atmospheric. Under these conditions, the conversion of hexoses reaches 96-100 %. The reaction products are preferably propylene glycol and ethylene glycol. The total selectivity for C3-2 polyols is 90-94 %, that is higher than in the hydrogenolysis of glucose in aqueous solution.


Author(s):  
Singh K. ◽  
Pandit K. ◽  
Mishra N.

The matrix tablets of cinnarizine and nimodipine were prepared with varying ratio of Carbopol- 971P and co-excipients of varying hydrophilicity (i.e. dicalcium phosphate and spray dried lactose) by direct compression and wet granulation using alcoholic mucilage. The prepared tablets were evaluated for weight variation, hardness and friability. The influence of concentration of the matrix forming material and co-excipients on the release rate of the drug was studied. The release rate of Cinnarizine (more soluble drug) from tablets followed diffusion controlled mechanism whereas for nimodipine (less soluble drug), the drug release followed case-II or super case- II transport mechanism based on Korsmeyer- Peppas equation. The results indicated that the drug release from matrix tablets was increases with increase in hydrophilicity of drug and co-excipients. The release of drug also increased with thermal treatment and decreasing polymer concentration.


Domiati cheese is the most popular brand of cheese ripened in brine in the Middle East in terms of consumed quantities. This study was performed to investigate the impact of the microbiological quality of the used raw materials, the applied traditional processing techniques and ripening period on the quality and safety of the produced cheese. Three hundred random composite samples were collected from three factories at Fayoum Governorate, Egypt. Collected samples represent twenty-five each of: raw milk, table salt, calf rennet, microbial rennet, water, environmental air, whey, fresh cheese, ripened cheese & swabs from: worker hands; cheese molds and utensils; tanks. All samples were examined microbiologically for Standard Plate Count (SPC), coliforms count, Staphylococcus aureus (S. aureus) count, total yeast & mould count, presence of E. coli, Salmonellae and Listeria monocytogenes (L. monocytogenes). The mean value of SPC, coliforms, S. aureus and total yeast & mould counts ranged from (79×102 CFU/m3 for air to 13×108 CFU/g for fresh cheese), (7×102 MPN/ cm2 for tank swabs to 80×106 MPN/ml for raw milk), (9×102 CFU/g for salt to 69×106 CFU/g for fresh cheese) and (2×102 CFU/cm2 for hand swabs to 60×104 CFU/g for fresh cheese), respectively. Whereas, E. coli, Salmonella and L. monocytogenes failed to be detected in all examined samples. There were significant differences in all determined microbiological parameters (p ≤0.05) between fresh and ripened cheese which may be attributed to different adverse conditions such as water activity, pH, salt content and temperature carried out to improve the quality of the product.


Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1055
Author(s):  
Hersh Chaitin ◽  
Michael L. Lu ◽  
Michael B. Wallace ◽  
Yunqing Kang

Many decellularized extracellular matrix-derived whole organs have been widely used in studies of tissue engineering and cancer models. However, decellularizing porcine esophagus to obtain decellularized esophageal matrix (DEM) for potential biomedical applications has not been widely investigated. In this study a modified decellularization protocol was employed to prepare a porcine esophageal DEM for the study of cancer cell growth. The cellular removal and retention of matrix components in the porcine DEM were fully characterized. The microstructure of the DEM was observed using scanning electronic microscopy. Human esophageal squamous cell carcinoma (ESCC) and human primary esophageal fibroblast cells (FBCs) were seeded in the DEM to observe their growth. Results show that the decellularization process did not cause significant loss of mechanical properties and that blood ducts and lymphatic vessels in the submucosa layer were also preserved. ESCC and FBCs grew on the DEM well and the matrix did not show any toxicity to cells. When FBS and ESCC were cocultured on the matrix, they secreted more periostin, a protein that supports cell adhesion on matrix. This study shows that the modified decellularization protocol can effectively remove the cell materials and maintain the microstructure of the porcine esophageal matrix, which has the potential application of studying cell growth and migration for esophageal cancer models.


Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2742
Author(s):  
Raquel Iglesias ◽  
Raúl Muñoz ◽  
María Polanco ◽  
Israel Díaz ◽  
Ana Susmozas ◽  
...  

The present work reviews the role of biogas as advanced biofuel in the renewable energy system, summarizing the main raw materials used for biogas production and the most common technologies for biogas upgrading and delving into emerging biological methanation processes. In addition, it provides a description of current European legislative framework and the potential biomethane business models as well as the main biogas production issues to be addressed to fully deploy these upgrading technologies. Biomethane could be competitive due to negative or zero waste feedstock prices, and competitive to fossil fuels in the transport sector and power generation if upgrading technologies become cheaper and environmentally sustainable.


2020 ◽  
Vol 164 ◽  
pp. 08031
Author(s):  
Evgeniy Velichko ◽  
Edward Tshovrebov ◽  
Ural Niyazgulov

The article deals with issues of monitoring, planning, organizational and technical support, economic regulation and improving the efficiency of the infrastructure for processing, recycling and disposal of waste, resource conservation and management of secondary resources, their use as secondary raw materials for production, services, work and power generation. The Russian Federation has significant potential for economic growth due to the efficient use of secondary resources from billions of tons of generated production and consumption waste annually. These ecologically unsafe anthropogenic objects can be characterized as a source of valuable renewable raw materials, material and fuel and energy resources. However, the scale and level of use of various types of secondary resources are characterized by considerable unevenness and depend on the demand for secondary raw materials, the resource value of the waste, the environmental situation arising from treating them as environmental polluters, on the real economic conditions that determine the profitability of each specific type. economic activities that use secondary resources for the manufacture of products, works, services, energy production. The methods of monitoring the industry for the treatment, disposal and disposal of waste are: information-analytical, information-statistical, sociological, geo-information. The legal status of the monitoring system of the industry for the treatment, disposal and disposal of waste is determined by the limitations of its functionality within the framework of the goals and objectives facing it.


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