Extrusion of Porous Protein-Based Polymers and Their Liquid Absorption Characteristics.

This research investigates the influence of various interface treatment methods on the frost resistance performance of Roller Compacted Concrete (RCC) layers. Freeze-thaw cycle tests were conducted on RCC with interfaces treated using cement mortar, expansion agent mortar, and nano-SiO2 mortar. The study evaluated shear failure modes, shear strength, crack expansion, pore structure, and liquid uptake of the RCC interface after freeze-thaw cycles under different treatment methods. Results reveal that expansion agent mortar and nano-SiO2 mortar improve the shear strength of RCC after freeze-thaw cycles more effectively than cement mortar. The freeze-thaw cycles increase the width and expansion rate of cracks at the RCC interface during the shear process, while mortar treatments help delay crack development. Additionally, the pore volume at the RCC interface gradually increases, and the uniformity of pore distribution decreases under freeze-thaw cycles. During liquid uptake, mortar treatments slow down the upward migration of liquids by improving the pore structure at the interface. The liquid uptake of RCC exhibits a distinct linear relationship with its shear strength and pore structure. As liquid uptake time increases, water first fills larger pores before gradually entering smaller ones. Freeze-thaw cycles cause an increase in pore volume and enlargement, which leads to greater liquid uptake. Based on the damage mechanism of the RCC interface under freeze-thaw conditions, a model of shear strength degradation due to freeze-thaw cycles was established, aligning well with experimental results. Mechanism analysis indicates that nano-SiO2 and expansion agents enhance frost resistance by filling interface pores and cracks through reactions with certain compounds, thereby improving the microstructure.

A great amount of biowastes, comprising byproducts and biomass wastes, is originated yearly from the agri-food industry. These biowastes are commonly rich in proteins and polysaccharides and are mainly discarded or used for animal feeding. As regulations aim to shift from a fossil-based to a bio-based circular economy model, biowastes are also being employed for producing bio-based materials. This may involve their use in high-value applications and therefore a remarkable revalorization of those resources. The present review summarizes the main sources of protein from biowastes and co-products of the agri-food industry (i.e., wheat gluten, potato, zein, soy, rapeseed, sunflower, protein, casein, whey, blood, gelatin, collagen, keratin, and algae protein concentrates), assessing the bioplastic application (i.e., food packaging and coating, controlled release of active agents, absorbent and superabsorbent materials, agriculture, and scaffolds) for which they have been more extensively produced. The most common wet and dry processes to produce protein-based materials are also described (i.e., compression molding, injection molding, extrusion, 3D-printing, casting, and electrospinning), as well as the main characterization techniques (i.e., mechanical and rheological properties, tensile strength tests, rheological tests, thermal characterization, and optical properties). In this sense, the strategy of producing materials from biowastes to be used in agricultural applications, which converge with the zero-waste approach, seems to be remarkably attractive from a sustainability prospect (including environmental, economic, and social angles). This approach allows envisioning a reduction of some of the impacts along the product life cycle, contributing to tackling the transition toward a circular economy.

Background:Wireless Sensor Network (WSN) is a collection of tiny electromechanical nodes termed as sensors. Sensors are equipped with sensing unit, which is designed for application specific. When deployed either by planned or unplanned after deployment, sensor’s energy starts depleting due to various roles like sensing, communication and aggregation.Method:WSN is challenged with limited battery power. The aim is to enhance energy efficiency that leads to a prolonged lifetime of networks.Results:We have reviewed the patents related to energy efficiency in wireless sensor networks. This Paper presents the study of various energy efficient techniques, which can enhance the lifetime of sensor networks; it covers basics of WSN, their design, Classification, Communication in WSN and a survey of different techniques for effective utilization of sensor’s energy.Conclusion:Paper has emphasized on energy efficient clustering technique along with feature wise summary of existing clustering protocols.

An efficient technique using citric acid and glucose based natural deep eutectic solvent (G-C-NADES) was developed to obtain ultrahigh deamidated wheat gluten (UDWG) (deamidation degree (DD) > 90%). FTIR and 1H NMR indicated intensive hydrogen bonds (HBs) in G-C-NADES supermolecules. Quantum chemical calculations and molecular dynamic simulations demonstrated that 10 wt % diluted G-C-NADES still had a myriad of HBs. Physicochemical results showed UDWG had DD up to 92.45% after G-C-NADES deamidation, that is, 22% higher than citric-acid-DWG with a weak degree of hydrolysis (1.75%). Conformational characterization demonstrated the obvious conversion from α-helix to β-sheet via FTIR, the least amount of disulfide bonds by Raman spectra, and more exposure of tryptophan residues by fluorescence measurement for UDWG. It is proven that enhanced accessible conformation of WG reached with HBs of G-C-NADESs could contribute to the improvement on nucleophilic attack of deamidation, declaring that G-C-NADES might be a potential solvent for obtaining an ultrahigh deamidation for WG to successfully guarantee the safety of wheat gluten based cereal food regarding to lowering its allergy.

Inorganic porous materials have long dominated the field of porous materials due to their stable structure and wide applications. In the past decade, porous polymers have generated considerable interest among researchers because of their easily tunable porosity, carbon-rich backbones, and prominent physical properties. These attributes enable porous polymers to be used in various applications such as sensing, gas separation and storage, catalysis, and energy storage. However, poor dispersibility has long hindered the development of porous polymers. A majority of the reported porous polymers can only be synthesized with amorphous structure through direct precipitation from solutions during reactions. The rational design and synthesis of porous polymers with controllable morphology, such as two-dimensional (2D) morphology, remains great challenge. Two-dimensional nanomaterials have attracted considerable interest because of their unique properties, which originate from the intrinsic chemical structures and 2D dimensionality. Among 2D nanomaterials, 2D porous polymers, which possess the advanced features of polymers, porous materials, and 2D nanomaterials, have been a rising star. Conventionally, polymerization strategies for generating 2D porous polymers mainly include the cross-linking of multiarmed monomers in 2D-space-confined environments, such as crystalline solid surfaces, liquid-liquid interfaces, and liquid-air interfaces. However, these methods always involve complicate operations, e.g., under vacuum, sophisticated equipment, film transfer technology, exfoliation, and so on and, most importantly, are difficult to scale up. To overcome this synthesis obstacle, 2D nanomaterials, such as graphene, can be used as 2D templates for synthesis of sandwich-like 2D porous polymers and porous carbon nanosheets. p-Bromobenzene-, p-cyanobenzene-, polyacrylonitrile-, and amino-functionalized graphene are used as templates for direct surface polymerization through reactions such as Sonogashira-Hagihara coupling reaction, condensation reaction, ionothermal reaction, reversible addition-fragmentation chain transfer polymerization, Friedel-Crafts reaction, and oxidation reaction. Therefore, sandwich-like 2D conjugated microporous polymers, Schiff-base type porous polymers, covalent triazine frameworks, hyper-cross-linked porous polymers, and mesoporous conducting polymers can be easily prepared. Beyond graphene, other excellent 2D nanomaterials, e.g., MoS2, can also act 2D templates to construct 2D porous polymers and corresponding hybrid materials. In addition, 2D morphology for porous polymer can be achieved without 2D templates in a few cases. For instance, olefin-linkage-linked covalent organic frameworks can be synthesized through Knoevenagel condensation reaction. As is known, porous polymers can serve as carbon-rich precursors to generate heteroatom doped porous carbons for energy storage and catalysis. Thus, one benefit of 2D porous polymers is new access toward porous carbon nanosheets through direct pyrolysis without using inorganic porous templates. In this Account, we summarize recent research on 2D porous polymers and corresponding porous carbon nanosheets.

Porous organic polymers with different pore structures for sensitive solid-phase microextraction of environmental organic pollutants

Palm wood powder derived from palm wood waste was utilized as a novel absorbent material. The investigation involved exploring its pore structure and size to achieve the controlled release of bioactive compounds from plai oil, providing protection against pathogenic bacteria and thereby extending the shelf life of broccoli. The palm wood sachet was prepared before being placed into the broccoli bag. The process to create the sachet involved freezing the palm wood at -10°C and then drying it at a temperature of 200°C. After drying, the material was ground to achieve a particle size of 20 mesh and then packaged into sachets made from wood pulp. The optimized palm wood plai oil sachet (PWPS), measuring 5×7cm, with a thickness of 0.58µm, was produced by soaking 2g of palm powder in plai oil at a concentration of 30µL/mL before drying and packing it inside a 5-L polyethylene plastic bag (24×34cm) along with broccoli (150g). The packages were kept at 4°C for 20days to determine the antimicrobial activity of the PWPS and broccoli quality. PWPS significantly inhibited the growth of Escherichia coli, Salmonella Typhimurium, Staphylococcus aureus, and Listeria monocytogenes in broccoli for at least 20days. The sachet demonstrated complete inhibition of all bacteria when reused at least two times and an 80% reduction in efficacy after three uses. Moreover, the PWPS controlled the growth of total aerobic bacteria and yeast and mold in broccoli, meeting microbiological criteria for up to 14days. Broccoli stored with PWPS showed good quality results and contained high antioxidant value. These results demonstrate the potential application of PWPS in controlling food pathogens and spoilage microbes during storage. PRACTICAL APPLICATION: This study introduces a novel absorbent material made from palm wood powder, addressing the need for utilizing abundant waste palm wood in the food industry. The material benefits the safe transportation of vegetables from farms to markets. Its porous structure allows efficient absorption of plai oil emulsion, ensuring pathogen-free and high-quality treated broccoli. The reusable sachets benefit farmers seeking to extend the shelf life of fresh produce. This cost-effective method utilizes plai oil vapor, making it suitable for large-scale production.

Recent advances on nitrogen-doped metal-free materials for the selective catalytic oxidation of hydrogen sulfide

Biomass carbon materials with porous array structures derived from soybean dregs for effective electromagnetic wave absorption

Thermoelectric ceramics for generators

Structural design, preparation and characterization of light, isotropic and robust statically determined organic frameworks as reusable adsorbents

Wireless sensor networks can be deployed in normal as well as rough environment for data gathering fashion. Sensor nodes are more easy to failure because of their battery sources are irreplaceable. In Wireless Sensor networks (WSN), the sensors near to the sink will drain out of their energy first, resulting in holes in the WSNs. An important base for energy efficient routing technique in wireless sensor networks is the formation of energy holes near the sink. In this paper we propose Adaptive Tree Based Sink Relocation (ATBR) model. The proposed mechanism uses information related to residual battery energy of sensor nodes to adaptively adjust the routing tree and relocating scheme for the sink.

Security and Energy efficiency are two key factors to be contemplated in the design of applications based on wireless sensor networks (WSNs). Optimization of energy consumption is obligatory for an increased life time of the network. Without security, attackers can disrupt the entire operation of sensor network by instigating diverse attacks like message tampering, message dropping either in partial or whole and message flooding etc. This work proposes a secure energy efficient attack resilient routing technique for zone based wireless sensor network with proactive detection of malicious zones and mitigation from the attacks. Different from earlier works on detecting each malicious node, this work cleaves the network to zones and allots a probabilistic fuzzy score to model the success ratio of packet propagation through the zone. The routing is adaptive to ongoing residual energy and security risks. A Firm decision cannot be made on the frameworks influencing the life time of the network considering it may influence the operations of network. Experimentation of the proposed solution is done in NS2 and contrasted with the existing solutions to prove the effectiveness of the approach.

PurposeFused deposition modeling enables multiscale structure control. However, most of this structural space is unexplored. Specifically, the impact of biomimetic porous structures on the mechanical behavior and reliability of common thermoplastics are unclear. In this work, porous structures inspired by the multifunctional crab exoskeleton were 3D-printed with different raster orientations, including fully rotating rasters similar to Bouligand structures found in biological materials. Tensile tests and simulations were performed to observe the stochastic behavior of fracture properties and to reveal the underlying origins of mechanical reliability in biomimetic porous systems.Design/methodology/approachTensile tests were performed on 3D-printed porous structures with four different rasters. These rasters were biomimetic Bouligand, semi-Bouligand, 00 raster and 45°/−45° raster. In addition, two different sets were manufactured to observe the impact of contours on the mechanical behavior. A total of 137 tensile tests were performed. A total of 88 finite element simulations were executed using Abaqus built-in Hashin damage initiation criterion and energy-based damage evolution law. Weibull analyses were performed to quantify the stochastic properties.FindingsBiomimetic Bouligand structure is effective in increasing fracture strength. Average fracture strength of the Bouligand structure was 33% higher compared to the default 45°/−45° and 10% higher compared to 00 rasters. Variations in strength were lower in Bouligand structure compared to the default 45°/−45° raster. However, 00 raster had the highest Weibull modulus m = 54 compared to Bouligand m = 25 and 45°/−45° m = 17. Simulations showed that Bouligand structure is effective in increasing the mechanical reliability through local damage accumulation around the holes. The simulated Weibull modulus of the Bouligand structure was 40 compared to the moduli of other rasters that ranged from 18 to 25.Practical implicationsThe mechanical reliability of porous Bouligand structures is higher compared to other rasters, which makes the biomimetic structure a better choice for industrial applications. Contours decrease the strength and strain at failure for 3D-printed porous structures. Bouligand structures with rotating raster orientations increased strength and strain at failure when contours are present in the porous structure.Originality/valueTo the best of the authors’ knowledge, this is the first study showing the effects of biomimetic raster orientations on the mechanical behavior and the effects of contours on the tensile fracture properties of 3D-printed porous acrylonitrile butadiene styrene using tensile tests and fracture simulations. This is the first study applying composite fracture model to anisotropic porous 3D-printed polymers.

“Joint-linker type gels”, which are synthesized by addition reactions between multi-functional compounds as joint molecules, and a,w-bifunctional compounds as linker molecules, have been developed in various systems. The resulting gels formed homogeneous network structure. The network structure (geometry of the network, mesh size) in the gels can be controlled by molecular structure of the joint molecule and length of the linker molecules. Click-type reactions are usable to synthesize the various types of the joint-linker type gels in various solvents. Compatibility between network structure and solvents affected the mechanical properties. Recently, we found that phase separation induced by the network formation in the gels yielded porous polymers in various reaction systems. The porous structure was controllable by the reaction conditions, monomer concentration, reaction temperature, and so on. Most of the joint-linker type porous polymers were unbreakable by compression test. The porous polymers also absorbed many kinds of solvents.