Preparation of microcrystalline cellulose from rice straw under microwave irradiation

A review of valorization of agricultural waste for the synthesis of cellulose membranes: Separation of organic, inorganic, and microbial pollutants

Agricultural waste presents a significant environmental challenge due to improper disposal and management practices, contributing to soil degradation, biodiversity loss, and pollution of water and air resources. To address these issues, there is a growing emphasis on the valorization of agricultural waste. Cellulose, a major component of agricultural waste, offers promising opportunities for resource utilization due to its unique properties, including biodegradability, biocompatibility, and renewability. Thus, this review explored various types of agricultural waste, their chemical composition, and pretreatment methods for cellulose extraction. It also highlights the significance of rice straw, sugarcane bagasse, and other agricultural residues as cellulose-rich resources. Among the various membrane fabrication techniques, phase inversion is highly effective for creating porous membranes with controlled thickness and uniformity, while electrospinning produces nanofibrous membranes with high surface area and exceptional mechanical properties. The review further explores the separation of pollutants including using cellulose membranes, demonstrating their potential in environmental remediation. Hence, by valorizing agricultural residues into functional materials, this approach addresses the challenge of agricultural waste management and contributes to the development of innovative solutions for pollution control and water treatment.

Preparation and characterization of microcrystalline cellulose from rice bran

BACKGROUND

Rice bran, a by-product of rice processing, has not been fully utilized except for the small amount used for raising animals. The raw material source requirements of microcrystalline cellulose are becoming increasingly extensive. However, the characteristics of preparing microcrystalline cellulose from rice bran have not been reported, which limits the application of rice bran.

RESULTS

Microcrystalline cellulose was obtained from rice bran by alkali treatment, delignification, bleaching and acid hydrolysis. The morphology, particle size distribution, degree of polymerization, crystallinity, and thermal stability of rice bran microcrystalline cellulose were analyzed. The chemical compositions, scanning electron microscopy and Fourier-transform infrared analysis for rice bran microcrystalline cellulose showed that the lignin and hemicellulose were successfully removed from the rice bran fiber matrix. The morphology of rice bran microcrystalline cellulose was shown to be of a short rod-shaped porous structure with an average diameter of 65.3 μm. The polymerization degree of rice bran microcrystalline cellulose was 150. The X-ray diffraction pattern of rice bran microcrystalline cellulose showed the characteristic peak of natural cellulose (type I), and its crystallization index was 71%. The rice bran microcrystalline cellulose may be used in biological composites with temperatures between 150 °C and 250 °C.

CONCLUSION

These results suggest the feasibility of using rice bran as a low-price source of microcrystalline cellulose. © 2024 Society of Chemical Industry.

Microcrystalline cellulose from soybean hull as an excipient in solid dosage forms: Preparation, powder characterization, and tableting properties

Microcrystalline cellulose (MCC) is one of the essential functional excipients in the formulation of tablets. The need for cheaper MCC sources has drawn significant attention to exploring renewable sources. In this study, MCC was produced from soybean hull (SBH), the primary by-product of the soy industry, using a novel, simplified, and cost-effective approach. Various characterization techniques were used to study the physicochemical properties and micromeritics of the SBH-based MCC powders and compare them to those of the commercial Avicel PH-101. SBH MCCs had a larger particle size, a broader particle size distribution, a higher degree of polymerization, a higher degree of crystallinity, better thermal stability, and slightly superior flowability and compressibility than Avicel PH-101. The tableting blends (containing 60 % MCC) were prepared, and the post-compression out-of-die Heckel analysis showed that formulations with aggregated SBH MCCs were less ductile than those made with Avicel PH-101, resulting in a lower porosity (better compressibility) of the latter at higher compression pressures. The hardness values for all formulations were above 6 kg, with higher values for those made with Avicel PH-101. The lubricant sensitivity was lower for SBH MCCs. All tablets made using developed formulations showed very low friability (<0.1 %) and short disintegration times (<90 s), making them well-suited candidates for manufacturing orally disintegrating tablets (ODTs).

Characterization of microcrystalline cellulose prepared from long and short fibers and its application in ibuprofen tablets

As a bio-based material, microcrystalline cellulose (MCC) has been applied in many fields including pharmaceuticals, foods, and cosmetics in recent years. However, traditional preparation methods of MCC are facing many challenges due to economic and eco-environmental issues. In this study, softwood dissolved pulp was sieved to long fiber (LF) and short fiber (SF), and subsequently to prepare LF-MCC and SF-MCC by hydrochloric acid hydrolysis at different acid dosages (3-7 wt%), reaction times (30-90 min), and temperatures (75-95 °C). The as-obtained MCC products were compared in terms of morphology, size, crystallinity, and chemical structure. The results indicated that the crystallinity and yield of LF-MCC were high, with maximum values of 78.41 % and 98.68 %, respectively. The particle size distribution of SF-MCC was more uniform in the range of 20-80 μm, with a maximum of 59.44 % at 20-80 μm occupancy proportion. Moreover, SF-MCC had a typical rod-like shape and larger surface area as well as better thermal behavior than LF-MCC. When LF-MCC and SF-MCC were used as fillers in the production of ibuprofen tablets, the tablets added with LF-MCC exhibited higher hardness, friability, dissolution rate, and shorter disintegration time. Therefore, this work is very beneficial for the preparation and application of MCC.

Near-Infrared (NIR) Silver Sulfide (Ag2S) Semiconductor Photocatalyst Film for Degradation of Methylene Blue Solution

A silver sulfide (Ag₂S) semiconductor photocatalyst film has been successfully synthesized using a solution casting method. To produce the photocatalyst films, two types of Ag₂S powder were used: a commercialized and synthesized powder. For the commercialized powder (CF/comAg₂S), the Ag₂S underwent a rarefaction process to reduce its crystallite size from 52 nm to 10 nm, followed by incorporation into microcrystalline cellulose using a solution casting method under the presence of an alkaline/urea solution. A similar process was applied to the synthesized Ag₂S powder (CF/syntAg₂S), resulting from the co-precipitation process of silver nitrate (AgNO₃) and thiourea. The prepared photocatalyst films and their photocatalytic efficiency were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and UV-visible spectroscopy (UV-Vis). The results showed that the incorporation of the Ag₂S powder into the cellulose films could reduce the peak intensity of the oxygen-containing functional group, which indicated the formation of a composite film. The study of the crystal structure confirmed that all of the as-prepared samples featured a monoclinic acanthite Ag₂S structure with space group P₂₁/C. It was found that the degradation rate of the methylene blue dye reached 100% within 2 h under sunlight exposure when using CF/comAg₂S and 98.6% for the CF/syntAg₂S photocatalyst film, and only 48.1% for the bare Ag₂S powder. For the non-exposure sunlight samples, the degradation rate of only 33-35% indicated the importance of the semiconductor near-infrared (NIR) Ag₂S photocatalyst used.

A critical review on the techniques used for the synthesis and applications of crystalline cellulose derived from agricultural wastes and forest residues

In order to meet the growing energy crisis of the 21st century, the utilization of bio-based materials has become a field of high research endeavour. In view of that, the present review paper is focused on different techniques that are frequently explored for the synthesis of value-added crystalline derivatives of cellulose like MCC and NCC from agricultural wastes and forest residues. Moreover, a comparative analysis between thermochemical and biochemical methods is carried out for such valorization of biomass considering the mechanism involved with various reactions. Further, a critical analysis is performed on various individual techniques specifically used for the applications of MCC and NCC in different fields including environmental, polymer industry, pharmaceutical and other emerging sectors. This article will assist the readers not only to explore new biomass sources but also provides an in-depth insight on various green and cost-effective methods for sustainable production of crystalline cellulose.

Advantages and Disadvantages of Bioplastics Production from Starch and Lignocellulosic Components

The accumulation of plastic wastes in different environments has become a topic of major concern over the past decades; therefore, technologies and strategies aimed at mitigating the environmental impacts of petroleum products have gained worldwide relevance. In this scenario, the production of bioplastics mainly from polysaccharides such as starch is a growing strategy and a field of intense research. The use of plasticizers, the preparation of blends, and the reinforcement of bioplastics with lignocellulosic components have shown promising and environmentally safe alternatives for overcoming the limitations of bioplastics, mainly due to the availability, biodegradability, and biocompatibility of such resources. This review addresses the production of bioplastics composed of polysaccharides from plant biomass and its advantages and disadvantages.

Preparation, characterization and its potential applications in Isoniazid drug delivery of porous microcrystalline cellulose from banana pseudostem fibers

Banana pseudostem, a cellulose-rich by-product, is regarded as an important agricultural waste during the process of banana production. Microcrystalline cellulose was successfully prepared from banana pseudostem using acid hydrolysis method. Microcrystalline cellulose was characterized through various techniques such as XRD, TGA, SEM, FTIR and antioxidant activity to explore the possible applications in the pharmaceutical industries especially as a drug delivery vehicle. The investigation revealed that the derived microcrystalline cellulose is non-aggregated, short rods with high crystallinity index 67% and stable up to 347 °C. FTIR spectroscopy showed that hydrolysis treatments are efficient for the removal of lignin and hemicellulose content. Microcrystalline cellulose exhibited good antioxidant activity 90.29% at 100 μg/ml. In vitro studies for the drug release were carried out in simulated intestinal fluid (SIF) using Isoniazid drug. The study proves that microcrystalline cellulose can be directly obtained from banana pseudostem which is not only beneficial to reduce the cost of traditional microcrystalline cellulose but is also conducive to the value-added utilization of the pseudostem.

Extraction and characterization of microcrystalline cellulose from waste cotton fabrics via hydrothermal method

A large amount of accumulated waste cotton fabrics (WCFs) have caused environmental problem and depletion of resources. The extraction of microcrystalline cellulose as value-added products is one of the effective ways to the recycling of WCFs. This study aimed to extract microcrystalline cellulose from WCFs by the hydrothermal method and compare the extracted microcrystalline cellulose (EMC) with Avicel PH101 microcrystalline cellulose (MCC). The EMC was extracted under hydrothermal conditions (solid-liquid ratio 1:30, HCl concentration 0.6 mol/L, 150 °C, 100 min), with a yield and the degree of polymerization of 85.54% and 228, respectively. The samples were characterized by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, nuclear magnetic resonance, thermogravimetric analysis and contact angle testing. The detailed analyses showed that the properties of EMC prepared from WCFs are similar to those of commercial MCC. The results indicated that WCFs is a critical and potential low-cost raw material to prepare MCC.