Effect of shear and heat milling of starch on the properties of tapioca starch/cellulose nanofiber composites

Bibliometric study and potential applications in the development of starch films with nanocellulose: A perspective from 2019 to 2023

This study aimed to perform a bibliometric analysis of starch films with nanocellulose, using the Scopus database and VOSviewer and Bibliometrix software. A total of 258 documents were identified between 2019 and 2023, reflecting a growing interest in research, particularly in journals such as the International Journal of Biological Macromolecules, Polymers, and Carbohydrate Polymers. The most common terms were "starch" (349 occurrences), "cellulose" (207), and "tensile strength" (175). China (58 articles), Brazil (38), and India (33) led scientific production, with authors like Ilyas (13 articles) and Sapuan (10) at the forefront. Approximately 41.7 % of the studies used corn starch. The analysis revealed that 66 % of the studies investigated films with cellulose nanofibrils (CNF), 32 % with cellulose nanocrystals (CNC), and 2 % with bacterial nanocellulose (CB). The majority of studies (94.1 %) used the casting method for film production. Additionally, 35.44 % focused on reinforcing films with nanocellulose, while 7 % developed blends with other biopolymers. About 59.44 % examined the performance of starch films for food packaging, 11.25 % explored practical applications in various foods. Furthermore, 7.94 % incorporated active agents to improve antioxidant and antimicrobial properties, 1.30 % investigated active packaging. Moreover, 2.36 % explored the use of films in materials engineering, and 2.36 % explored biomedical potential. Only 0.40 % evaluated the impact of films on wastewater treatment. The analysis highlights the potential of starch films with nanocellulose, demonstrating their diverse applications and the growing interest in the field.

The rigid-flexible balanced molecular crosslinking network transition interface: An effective strategy for improving the performance of bamboo fibers/poly(butadiene succinate-co-butadiene adipate) biocomposites

The poor interfacial compatibility of natural fiber-reinforced polymer composites has become a major challenge in the development of industry-standard high-performance composites. To solve this problem, this study constructs a novel rigid-flexible balanced molecular crosslinked network transition interface in composites. The interface improves the interfacial compatibility of the composites by balancing the stiffness and strength of the fibers and the matrix， effectively improving the properties of the composites. The flexural strength and flexural modulus of the composites were enhanced by 38 % and 44 %, respectively. Water absorption decreased by 30 %. The initial and maximum thermal degradation temperatures increased by 20 °C and 16 °C, respectively. The maximum storage modulus increased by 316 %. Furthermore, the impact toughness was elevated by 41 %, attributed to the crosslinked network's efficacy in absorbing and dissipating externally applied energy. This innovative approach introduces a new theory of interfacial reinforcement compatibility, advancing the development of high-performance and sustainable biocomposites.

Highly efficient removal of tannic acid from wastewater using biomimetic porous materials

To effectively remove tannic acid (TA) from wastewater, using green and natural materials has attracted increasing attention. Inspired by Galla Chinensis (GC) with high content of TA, this study synthesized a biomimetic porous adsorbent to mimic the GC structure using dialdehyde tapioca starch (DTS) and gelatin (GL). The TA adsorption performance and mechanism of synthetic porous material were investigated. Results revealed that the porous material exhibited a maximum TA adsorption capacity of 1072.01 mg/g, along with a high removal rate of 95.16% under the conditions of a DTS-GL mass ratio of 1:1, DTS aldehyde content of 48.16%, a solid content of 5%, and a pH of 2 at 25 °C. The adsorption of TA by DTS was not affected by water-soluble cationic and anion. The adsorption kinetics of TA on the porous material followed the pseudo-second-order model, and this Langmuir adsorption model (R2 = 0.9954) which were well described the adsorption of TA by the material, indicating that the adsorption primarily occurred in a monolayer. FTIR, XRD, DSC, TG, XPS, and SEM-EDS were employed to characterize the structure characteristics of the porous material. The cross-linking between DTS and GL by Schiff base reaction imparted a chemical structure could absorb TA by hydrogen bonding. The TA desorption rates of in 30% acetone and 40% ethanol solutions were 88.76% and 91.03%, respectively. The porous material prepared by the GC-inspired approach holds promise as an ideal choice for loading polyphenolic compounds and provides a new perspective for the design and application of bioinspired engineering materials.

Mechanical activation-enhanced metal-organic coordination strategy to fabricate high-performance starch/polyvinyl alcohol films by extrusion blowing

The production of high-performance starch-based packaging films by extrusion blowing is challenging, ascribed to poor processability of the blend precursors. In this study, a new strategy of mechanical activation (MA)-enhanced metal-organic coordination was proposed to improve the processability of starch (St)/polyvinyl alcohol (PVA) blend precursor, with calcium acetate (CA) as a chelating agent and glycerol as a plasticizer. MA pretreatment activated the hydroxyl groups of starch and PVA for constructing strong metal-organic coordination between CA and St/PVA during reactive extrusion, which effectively enhanced the melt processing properties of the blend precursor, contributing to the fabrication of high-performance St/PVA films by the extrusion-blowing method. The as-prepared St/PVA films exhibited excellent mechanical properties (tensile strength of 34.5 MPa; elongation at break of 271.8 %), water vapor barrier performance (water vapor permeability of 0.704 × 10-12 g·cm-1·s-1·Pa-1), and oxygen barrier performance (oxygen transmission rate of 0.7 cm3/(m2·day·bar)), along with high transmittance and good uniformity. These outstanding characteristics and performances can be attributed to the improved interfacial interaction and compatibility between the two matrix phases. This study uncovers the mechanism of MA-enhanced metal-organic coordination for improving the properties of starch-based films, which provides a convenient and eco-friendly technology for the preparation of high-performance biodegradable films.

Recent advances in starch-based coatings for the postharvest preservation of fruits and vegetables

Efficient and low-cost postharvest preservation of fruits and vegetables has always been one of the urgent problems to be solved in the food field. Due to the wide sources, good environmental and human safety, and high biodegradability, starch-based coating preservation method has great application prospects in the postharvest preservation of fruits and vegetables. However, starch materials also have the disadvantages of poor mechanical properties and easy water absorption performance, which makes it difficult to fully meet the requirements in practical production. Therefore, starch is often used in combination with other components to form composite materials. This paper began with an introduction to the preservation principles of edible starch-based coatings, including inherent properties and extra functional properties. Besides, the preservation principles of edible coatings and the recent advances in the field of fruit and vegetable preservation were also comprehensively reviewed, focusing on the preparation and application of starch-based coatings. The information will contribute to the further development of starch-based coatings to improve the postharvest preservation effect of fruits and vegetables.

Preparation and characterization of chemically modified tapioca starch-ionic liquid antibacterial films

The plasticizing and antibacterial effects of ionic liquids (ILs) in the preparation of tapioca starch-IL films were studied for the first time. 1-Ethyl-3-methylimidazolium acetate ([Emim][OAc]) caused complete disruption of starch crystallites during thermal compression, while some crystallites remained after the plasticization of starch with choline acetate ([Ch][OAc]). Compared to native tapioca starch (NTS), the plasticization of acetylated tapioca starch (ATS) and cross-linked tapioca (CTS) was slightly promoted and inhibited, respectively. Starch-[Emim][OAc] films exhibited higher hydrophobicity and mechanical properties but lower antibacterial activity than starch-[Ch][OAc] films. CTS-[Ch][OAc] films presented higher mechanical strength and antibacterial activity than NTS-[Ch][OAc] and ATS-[Ch][OAc] films. From this study, we conclude that ILs can be used in the preparation of antibacterial starch films to play the roles of plasticization and antibacterial activity. The antibacterial activity of starch films depends on types of ILs and their interactions with starch during film preparation.

Flame-retardant phytic acid-decorated thermoplastic starch/halloysite nanotube composite films with enhanced mechanical strength and excellent barrier properties

Thermoplastic starch (TPS), a green and fully biodegradable composite, is considered the most viable option for replacing petroleum-based polymers. However, the poor mechanical properties, high flammability and moisture absorption susceptibility of TPS severely restrict its large-scale applications. Through PA phosphorylation and blending with halloysite nanotubes (HNTs), phytic acid (PA)-phosphorylated HNT/TPS composite films (HNTPSFs) were fabricated with enhanced mechanical strength, excellent flame retardancy, and improved barrier properties. The introduction of HNTs substantially increased the mechanical properties (tensile strength increased 54.3 % and elongation at break decreased 37.0 %) of TPS films and reduced the diffusion of water vapor (decreased 34.1 %). Thermogravimetric analysis studies demonstrated that the HNTPSFs had exceptional thermal stability at their anticipated working temperatures. Furthermore, when the PA content in the composite films increased, the peak heat release rate, total heat release and fire growth index of the HNTPSFs all decreased substantially, demonstrating the improved flame retardancy of HNTPSFs. Hence, the synthesized fully biodegradable TPS composites show enormous potential in the field of renewable biopolymers.