Journal of Bioresources and Bioproducts最新文献

Petroleum-based materials are often used in the packaging industry. However, the single use value of such products can be problematic with regard to proper waste disposal. As such, molded pulp packaging can be used as an alternative, given its ease of recycling, composting, and eventual biodegradation. In this work, we aims to study the pulp properties of sunn hemp and its usage as molded pulp products. For this purpose, unbleached beaten and unbeaten soda pulps derived from the whole stem of sunn hemp were examined for their fiber morphology, fibrillation, fiber classification, and physical properties. The sunn hemp pulp was subsequently molded using a batch molding machine. To determine the hydrophobicity of the molded pulp products, the molded samples were manufactured with and without additives. Finally, some properties of the molded pulp products were examined and compared with the commercially available bleached bagasse molded pulp products. It was observed that the molded products made from sunn hemp pulp with additives had a higher water contact angle than that of the commercial products. In terms of general usage, the molded products from sunn hemp pulp with additives were found to be capable of storing hot water, hot cooking oil, as well as microwaving water. We concluded that the sunn hemp pulp could be used as an alternative fibrous raw material in the production of molded pulp packaging.

Boron (B) and nitrogen (N) co-doped 3D hierarchical micro/meso porous carbon (BNPC) were successfully fabricated from cellulose nanofiber (CNF)/ boron nitride nanosheets (BNNS)/ zinc-methylimidazolate framework-8 (ZIF-8) nanocomposites prepared by 2D BNNS, ZIF-8 nanoparticles, and wheat straw based CNFs. Herein, CNF/ZIF-8 acts as versatile skeleton and imparts partial N dopant into porous carbon structure, while the introduced BNNS can help strengthen the hierarchical porous superstructure and endow abundant B/N co-dopants within BNPC matrix. The obtained BNPC electrode possesses a high specific surface area of 505.4 m²/g, high B/N co-doping content, and desirable hydrophilicity. Supercapacitors assembled with BNPC-2 (B/N co-doped porous carbon with a CNF/BNNS mass ratio of 1꞉2) electrodes exhibited exceptional electrochemical performance, demonstrating high capacitance stability even after 5 000 charge-discharge cycles. The devices exhibited outstanding energy density and power density, as well as the highest specific capacitance of 433.4 F/g at 1.0 A/g, when compared with other similar reports. This study proposes a facile and sustainable strategy for efficiently fabrication of rich B/N co-doped hierarchical micro/meso porous carbon electrodes from agricultural waste biomass for advanced supercapacitor performance.

Lignin, as a natural antioxidant, shows great potential in food engineering and medicine. However, the inherent macromolecular structure, high polydispersity, and few phenolic hydroxy seriously limit its antioxidant activity. In this work, a mild iodocyclohexane demethylation for highly improving the antioxidant activity of lignin was proposed. The results showed –OCH₃ content exhibited an almost linear decrease as a function of treating time, and the demethylation and cleavage of β–aryl ether bonds prompt an obvious increase in phenolic hydroxyl content (4.01 mmol/g) and a significant decline in aliphatic hydroxyl (∼0.03 mmol/g). Meanwhile, attributing to the fragmentation of β–O–4, β–β, and β–5 substructures, the polydispersity of lignin molecular weight decreases from 2.7 to 2.2. As a result, the formed catechol-typed lignin showed an outstanding antioxidant activity, with the radical (DPPH·) scavenging index (inverse of concentration for 50% of maximal effect (EC₅₀) value) over 2 000 mL/mg, much superior to the commercial antioxidants (< 500 mL/mg). Further structure-activity relationship analysis implied that the Ph–OH/–OCH₃ ratio might act as a key factor influencing the antioxidant activity of lignin. This mild demethylation demonstrates a facile and effective method for highly enhancing the antioxidant activity of lignin and makes the catechol-typed lignin a green and promising product for practical use in food, medicine, and pharmacy.

It is crucial to adapt the processing of forest bio-resources into biochemicals and bio-based advanced materials in order to transform the current economic climate into a greener economy. Tall oil, as a by-product of the Kraft process of wood pulp manufacture, is a promising resource for the extraction of various value-added products. Tall oil fatty acids-based multifunctional Michael acceptor acrylates were developed. The suitability of developed acrylates for polymerization with tall oil fatty acids-based Michael donor acetoacetates to form a highly cross-linked polymer material via the Michael addition was investigated. With this novel strategy, valuable chemicals and innovative polymer materials can be produced from tall oil in an entirely new way, making a significant contribution to the development of a forest-based bioeconomy. Two different tall oil-based acrylates were successfully synthesized and characterized. Synthesized acrylates were successfully used in the synthesis of bio-based thermoset polymers. Obtained polymers had a wide variety of mechanical and thermal properties (glass transition temperature from –12.1 to 29.6 °C by dynamic mechanical analysis, Young's modulus from 15 to 1 760 MPa, and stress at break from 0.9 to 16.1 MPa). Gel permeation chromatography, Fourier-transform infrared (FT-IR) spectroscopy, matrix-assisted laser desorption/ionization-time of flight mass spectrometry, and nuclear magnetic resonance were used to analyse the chemical structure of synthesized acrylates. In addition, various titration methods and rheology tests were applied to characterize acrylates. The chemical composition and thermal and mechanical properties of the developed polymers were studied by using FT-IR, solid-state nuclear magnetic resonance, thermal gravimetric analysis, differential scanning calorimetry, dynamic mechanical analysis, and universal strength testing apparatus.

In the present study, the hydrolysates generated via autohydrolysis of spruce wood chips were directly used as feedstock for producing coagulants. The in-situ polymerization of acrylamide (AM) and lignocellulose (LC) of hydrolysates was successfully conducted. The reaction was optimized to generate lignocellulose-acrylamide (LC-AM) with the highest molecular weight (41,060 g/mol) and charge density (–0.25 meq/g) under the optimum conditions, which were 3 h, 60 ℃, 4% (w) initiator based on the dried mass of hydrolysate, and an AM/LC molar ratio of 5.63. A nuclear magnetic resonance (NMR) spectroscopy confirmed the grafting of acrylamide on LC. Other properties of LC-AM were characterized by the elemental analyzer, zeta potential analyzer, gel permeation chromatography (GPC), and particle charge detector (PCD). The LC-AM was applied as a coagulant for removing ethyl violet dye from a simulated dye solution. The results indicated that 47.2% dye was removed from the solution at a low dosage of 0.2 g/g. The dual flocculation of LC-AM with other polymers for dye removal is suggested to further improve its effectiveness.

Passive cooling strategy shows great potential in mitigating global warming and reducing energy consumption. Because of the high emissivity in the atmospheric transparency window (λ ≈ 8–13 µm), cellulose is considered as a good candidate for radiative cooling. However, traditional cellulose coolers generally show poor solar reflection and can be polluted by dust outside, thereby resulting in poor daytime cooling efficiency. To address these drawbacks, we developed sustainable cellulose nanowhiskers (CNWs)/ZnO composite aerogel films with favorable optical performance, mechanical robustness, and self-cleaning function for efficient daytime radiative cooling, which can be achieved via freeze casting and hot-pressing process. Due to formation of multi-level porous structure and chemical bonds (Si-O-C/Si-O-Si), such aerogel film exhibited high solar reflectance (97%) and high infrared emittance (92.5%). It achieved a sub-ambient temperature drop of 6.9 °C under direct sunlight in hot weather. Most importantly, the surface roughness and low surface energy enable cellulose aerogel film hydrophobicity (contact angle = 133°), thereby resulting in an anti-dust function. This work provides insight into the design of sustainable thermal regulating materials to realize carbon neutrality.

Conventional plastics exacerbate climate change by generating substantial amounts of greenhouse gases and solid wastes throughout their lifecycle. To address the environmental and economic challenges associated with petroleum-based plastics, bioplastics have emerged as a viable alternative. Bioplastics are a type of plastic that are either biobased, biodegradable, or both. Due to their biodegradability and renewability, bioplastics are established as earth-friendly materials that can replace nonrenewable plastics. However, early bioplastic development has been hindered by higher production costs and inferior mechanical and barrier properties compared to conventional plastics. Nevertheless, studies have shown that the addition of additives and fillers can enhance bioplastic properties. Recent advancements in bioplastics have incorporated special additives like antibacterial, antifungal, and antioxidant agents, offering added values and unique properties for specific applications in various sectors. For instance, integrating antibacterial additives into bioplastics enables the creation of active food packaging, extending the shelf-life of food by inhibiting spoilage-causing bacteria and microorganisms. Moreover, bioplastics with antioxidant additives can be applied in wound dressings, accelerating wound healing by preventing oxidative damage to cells and tissues. These innovative bioplastic developments offer promising opportunities for developing sustainable and practical solutions in various fields. Within this review are two main focuses: an outline of the bioplastic classifications to understand how they fit in as the coveted conventional plastics substitute and an overview of the recent bioplastic innovations in the antibacterial, antifungal, and antioxidant applications. We cover the use of different polymers and additives, presenting the findings and potential applications within the last decade. Although current research primarily focuses on food packaging and biomedicine, the exploration of bioplastics with specialized properties is still in its early stages, offering a wide range of undiscovered opportunities.

Carbothermal reduction using biochar (BC) is a green and effective method of synthesizing BC-supported nanoscale zero-valent iron (nanoFe⁰) composites. However, the effect of BC surface area on the structure, distribution, and performance such as the heavy metal uptake capacity of nanoFe⁰ particles remains unclear. Soybean stover-based BCs with different surface areas (1.7 − 1 472 m²/g) were prepared in this study. They have been used for in-situ synthesis BCs-supported nanoFe⁰ particles through carbothermal reduction of ferrous chloride. The BCs-supported nanoFe⁰ particles were found to be covered with graphene shells and dispersed onto BC surfaces, forming the BC-supported graphene-encapsulated nanoFe⁰ (BC-G@Fe⁰) composite. These graphene shells covering the nanoFe⁰ particles were formed because of gaseous carbon evolved from biomass carbonization reacting with iron oxides/iron salts. Increasing BC surface area decreased the average diameters of nanoFe⁰ particles, indicating a higher BC surface area alleviated the aggregation of nanoFe⁰ particles, which resulted in higher heavy metal uptake capacity. At the optimized condition, BC-G@Fe⁰ composite exhibited uptake capacities of 124.4, 121.8, 254.5, and 48.0 mg/g for Cu²⁺, Pb²⁺, Ag⁺, and As³⁺, respectively (pH 5, 25 °C). Moreover, the BC-G@Fe⁰ composite also demonstrated high stability for Cu²⁺ removal from the fixed-bed continuous flow, in which 1 g of BC-G@Fe⁰ can work for 120 h in a 4 mg/L Cu²⁺ flow continually and clean 28.6 L Cu²⁺ contaminated water. Furthermore, the BC-G@Fe⁰ composite can effectively immobilize the bioavailable As³⁺ from the contaminated soil, i.e., 5% (w) of BC-G@Fe⁰ composite addition can immobilize up to 92.2% bioavailable As³⁺ from the contaminated soil.

Hydrogen as a clean energy carrier has attracted great interests world-wide for substitution of fossil fuels and for abatement of the climate change concerns. However, green hydrogen from renewable resources is less than 0.1% at present in the world hydrogen production and this is largely from water electrolysis which is beneficial only when renewable electricity is used. Hydrogen production from diverse renewable resources is desirable. This review presents recent advances in hydrogen production from woody biomass through biomass steam gasification, producer gas processing and H₂/CO₂ separation. The producer gas processing includes steam-methane reforming (SMR) and water-gas shift (WGS) reactions to convert CH₄ and CO in the producer gas to H₂ and CO₂. The H₂ storage discussed using liquid carrier through hydrogenation is also discussed. The CO₂ capture prior to the SMR is investigated to enhance H₂ yield in the SMR and the WGS reactions.