Effect of branched 1,4-butanediol citrate oligomers with different molecular weights on toughness and aging resistance of glycerol plasticized starch.

The thermoplastic starch with glycerol is easy to retrograde and sensitive to hygroscopicity. In this study, branched 1,4-butanediol citrate oligomers with different molecular weights (P1, P2, and P3) are synthesized, and then mixed with glycerol (G) as the co-plasticizers to prepare thermoplastic starch (CS/PG). The results show that the molecular weight and branching degree of the branched 1,4-butanediol citrate oligomers increase as reaction time prolongs. Compared with glycerol plasticized starch, the thermoplastic starch films with branched 1,4-butanediol citrate oligomers/glycerol (10 wt%/20 wt%) have a better toughness, transmittance, and aging resistance, and have a lower crystallinity, hygroscopicity, and thermal stability. The toughness, transmittance, and aging resistance of CS/PG films are positively correlated with the molecular weight of the branched 1,4-butanediol citrate oligomers. These are due to the fact that the branched 1,4-butanediol citrate oligomer with a high molecular weight could form a stronger hydrogen bond and the more stable cross-linked structure with starch chains than that with a lower molecular weight. The elongation at break of CS/P3G film stored for 3 and 30 d are 98.0 % and 88.1 %, respectively. The mixture of branched butanediol citrate oligomers and glycerol, especially P3/G, has a potential application in the preparation of thermoplastic starch.

Balancing energy security and marine pollution prevention: legal challenges of utilizing nuclear power for decarbonizing maritime transportation in the Arctic region.

The Arctic region is facing growing demands for energy to support various economic activities, while also grappling with the profound impacts of climate change. Black carbon particulate matter emissions reduction is a key objective to mitigate the susceptibility of the Arctic's ecosystems to the impact of climate change. Nuclear power has been suggested as a potential source of clean energy to decarbonize maritime transport in the Arctic. However, although the operation of nuclear-powered vessels and floating nuclear power platforms in the region ensures energy security and reduces black carbon emissions, it may pose significant risks of nuclear material release and radiological accidents and raise concerns about improper radioactive waste disposal. In regulating these nuclear-powered vessels and floating nuclear power platforms in the Arctic, the existing international legal regime faced a series of challenges. This research employs a method of policy analysis to analyze these legal challenges and explores how the international community could work together to cope with the challenges that arise in the Arctic during the operation of nuclear-powered vessels and platforms for maritime decarbonization purposes.

Using Nuclear Energy for Maritime Decarbonization and Related Environmental Challenges: Existing Regulatory Shortcomings and Improvements.

In recent years, the use of nuclear energy as propulsion for merchant ships has been proposed as a means of promoting the transition toward maritime decarbonization and environmentally sustainable shipping. However, there are concerns that nuclear-powered merchant ships could pose risks to the marine environment in the event of accidents, such as collisions, machinery failure or damage, fire, or explosions. The current international regulatory framework for nuclear-powered merchant ships is insufficient to address these risks. This research aims to address this gap by conducting a policy analysis of the existing regulations and a critical examination of their effectiveness in addressing the environmental risks of nuclear-powered merchant ships. Through this analysis, the study identifies the shortcomings and insufficiencies in the current framework and explores potential solutions to improve it, with the goal of enhancing the international community's ability to mitigate the potential impacts of radioactive marine pollution from nuclear-propelled ships in an era of maritime decarbonization.

Preparation and characterization of starch-based nanocomposites reinforced by graphene oxide self-assembled on the surface of silanecouplingagent modified cellulose nanocrystals.

The dispersion of cellulose nanocrystal (CNC) in starch matrix limited its application. In this study, CNC modified by silanecouplingagent before graphene oxide (GO) self-assembled on the surface of modified CNC, then CNC-GO as a filler was used to prepare starch-based nanocomposite films (CS/CNC-GO). The structure of CNC-GO and CS/CNC-GO films and the properties of CS/CNC-GO films were studied by FT-IR, Raman, SEM, surface potential, UV-Vis, moisture absorption and tensile tests. The results showed that GO was successfully self-assembled on the surface of CNC modified by silanecouplingagent. CNC-GO was superior to CNC in reinforcing the strength of starch film, improving the transmittance of starch film and decreasing moisture rate of starch film. Tensile strength, elongation at break and transmittance of CS/CNC-GO film with 5 wt% CNC-GO reached maximum, which was 53.96 MPa, 3.72% and 38.76%, respectively. Moisture rate of CS/CNC-GO film with 3 wt% CNC-GO reached minimum that was 12.13%. These were assigned to the more uniform dispersion of CNC-GO in the starch matrix and the stronger interfacial interaction between starch and CNC-GO.

A comparative investigation of gelatinized and regenerated starch composites reinforced by microfibrillated cellulose.

This research demonstrated a novel and ecofriendly method for producing regenerated starch (RS)/microfibrillated cellulose (MFC) composite films with a nearly 1.4-fold improvement in tensile strength than traditional gelatinized starch (GS) films. Pure starch was dissolved in 14 wt% urea/4 wt% sodium hydroxide (NaOH) solution at 0 °C. Then, RS films and their biocomposite films containing MFC were prepared by dialyzing and solution-casting method. Results showed that the tensile strength and elongation at break of RS increased by 44.8% and 82.4%, compared with that of GS film, respectively. Owing to the adequate dispersion, lower viscosity-average molecular weight, higher amylose content, lower crystallinity and smaller crystal grain size, RS/MFC composite films exhibited significantly improved mechanical properties. The novel strategy used in this study will be helpful in preparing regenerated starch materials with excellent mechanical properties and biodegradability as alternatives to petrochemical plastics for the development of sustainable materials.

Preparation and Performance Evaluation of Antibacterial Melt-Spun Polyurethane Fiber Loaded with Berberine Hydrochloride.

(1) Background: Bacterial infections have long threatened global public safety; hence, it is significant to continuously develop antibacterial fibers that are closely related to people's daily lives. Berberine hydrochloride is a natural antibacterial agent that has application prospects in the preparation of antibacterial fibers. (2) Methods: This study firstly verified the antibacterial properties of berberine hydrochloride and its possible antibacterial mechanism. Thereafter, berberine hydrochloride was introduced into the self-made melt-spun polyurethane fiber through optimized coating technology. The performance of coating modified polyurethane fiber has been systematically evaluated, including its antibacterial properties, mechanical properties, and surface wettability. (3) Results: Results show that the antibacterial polyurethane fiber with desirable comprehensive properties is expected to be used in the biomedical fields. (4) Conclusions: The research also provides a reference for the development and application of other natural antibacterial ingredients in fiber fields.

Transition Metal and Metal-Nx Codoped MOF-Derived Fenton-Like Catalysts: A Comparative Study on Single Atoms and Nanoparticles.

To deal with the ever-growing toxic benzene-derived compounds in the water system, extensive efforts have been dedicated for catalytic degradation of pollutants. However, the activities and efficiencies of the transition metal-based nanoparticles or single-atom sites are still ambiguous in Fenton-like reactions. Herein, to compare the Fenton-like catalytic efficiencies of the nanoparticles and single atoms, the free-standing nanofibrous catalyst comprising Co nanocrystals and Co-Nx codoped carbon nanotubes (CNTs) or bare Co-Nx doped CNTs is fabricated. It is noteworthy that all these nanofibrous catalysts exhibit efficient activities, mesoporous structures, and conductive carbon networks, which allow a feasible validation of the catalytic effects. Benefiting from the maximized atomic utilization, the atomic Co-Nx centers exhibit much higher reaction kinetic constant (κ = 0.157 min-1 ) and mass activity toward the degradation of bisphenol A, far exceeding the Co nanocrystals (κ = 0.082 min-1 ). However, for the volume activities, the single-atom catalyst does not show apparent advantages compared to the nanocrystal-based catalyst. Overall, this work not only provides a viable pathway for comparing Fenton-like catalytic effects of transition metal-based nanoparticles or single atoms but also opens up a new avenue for developing prominent catalysts for organic pollutants' degradation.

Synergistic effects of sodium adipate/triethylene glycol on the plasticization and retrogradation of corn starch.

Starch retrogradation resulted in bad performance and taste of starch products. In this study, the corn starch films modified by sodium adipate and triethylene glycol were prepared by solution casting. The retrogradation of modified starch films were studied by FT-IR, XRD, SEM, tension test and UV-Vis. The results showed that sodium adipate was more effective than triethylene glycol in inhibiting the short-term retrogradation of starch, and triethylene glycol was more effective than sodium adipate in inhibiting the long-term retrogradation of starch. However, the mixture of sodium adipate and triethylene glycol, especially 15% adipic acid and 10% triethylene glycol, showed synergistic effects on the short-term and long-term retrogradation of starch. The starch film with 15% adipic acid and 10% triethylene glycol had the highest elongation at break, the best transmittance, the lowest change rate of elongation at break, and the lowest moisture content among all the recipes.

Effect of hyperbranched poly(trimellitic glyceride) paired with different metal ions on the physicochemical properties of starch.

The novel hyperbranched poly(trimellitic glyceride) (PTG) starch plasticizer synthesized in our previous study was neutralized with different alkaline metal hydroxides. Mixed with starch, the effects of different alkaline metal cations, M+, on gelatinization of starch suspensions and thermal behaviors of the films were analyzed using RVA and DMA, respectively. The structures of the starch suspensions, films and freeze-dried samples (S/PTG-M) were investigated using DSC, XRD and FTIR spectroscopy, respectively. M+ increased the gelatinization temperature of starch suspensions in the order of S/PTG-Li > S/PTG-Na > S/PTG-K. The formation of a complex between M+ and starch in the films observed using FTIR spectroscopy improved the stability of the starch paste and gel, and increased the gel temperature of starch dispersions. The corresponding starch gel was relatively thermostable, but not shear-resistant. PTG decreased the Tg of starch films with different paired M+. PTG-Li and PTG-K, but not PTG-Na, strengthened the mechanical properties of starch films.

Effect of sodium citrate/polyethylene glycol on plasticization and retrogradation of maize starch.

Maize starch was plasticized by mixtures of sodium citrate and polyethylene glycol 200 (PEG200) at varied weight ratios (citric acid/PEG200, 25/0, 20/5, 15/10, 10/15, 5/20 and 0/25). The structure and pasting, aging, moisture absorption and thermal properties of the plasticized starches were studied by means of Fourier transformed infrared, X-ray diffraction, rapid viscosity analysis, tension test and thermogravimetric analysis. Comparing with single plasticizer, co-plasticizers with appropriate proportions are more effective in hindering the retrogradation of starch paste and film. The results also showed that the mechanical property and humidity sensitivity of the starch film worsen after the introduction of PEG200 compared with sodium citrate plasticized starch, but the thermal stability and anti-aging property increase. This is consistent with the association ability of plasticizers with starch observed from FTIR. In addition to the simple additive effect of components on some properties, special formulations also show some synergistic effects, such as the co-plasticizer of 20% citric acid and 5% PEG200 has a better comprehensive property for plasticizing the maize starch bulk than sodium citrate or PEG200 alone. The mixture of sodium citrate and PEG200 can be used as a candidate plasticizer for preparing thermoplastic starch for food and packaging industries.

Programmable Release of Berberine Chloride Hydrate from Shape Memory Fibers Prepared from Core-Sheath Wet-Spinning Technology.

Smart wet-spun fibers for highly programmable release of therapeutic drug have been rarely reported. Herein, thermalresponsive composite fibers were successfully prepared by core-sheath wet-spinning technology in present study. They consisted of a model drug of natural antibacterial berberine chloride hydrate (BCH) and a drug carrier of temperature responsive shape memory polyurethane (SMPU). The obtained composite fibers featured with well-controlled microscopic morphologies, exhibiting significantly enhanced thermal stability and superb mechanical properties. In vitro drug release test and corresponding release kinetics study were performed for investigation of BCH's release behavior. Results demonstrated that the release behaviors of BCH from the core-sheath fibers were pH-dependent, influenced by both diffusion from pore channels and the solubility of BCH in the release mediums, and BCH imbedded only in core part showed a longer release period compared with that in both core and sheath parts of the composite fibers. More importantly, the release rate of BCH can be simply controlled by changing the initial shapes of fibers through stretching and fixation of the stretched deformations. Furthermore, the antibacterial durability of the smart composites fibers was demonstrated and tracked according to the growth inhibition against both negative E. coli and positive S. aureus bacteria strains. All these results suggest that the developed composite fibers can be promising candidates as smart drug delivery vehicles for highly adjustable doses of target drugs towards practical applications.

Super-tough poly (l-lactide) materials: Reactive blending with maleic anhydride grafted starch and poly (ethylene glycol) diacrylate.

Super-tough poly (l-lactide) (PLLA) without compromising its biodegradability and biocompatibility was fabricated by reactive blending with PLLA and maleic anhydride grafted starch (MS)/poly (ethylene glycol) diacrylate (PEGDA). PEGDA as reactive compatibilizer exhibits higher compatibilization efficiency and significant plasticization effect in PLLA matrix. Fourier transform infrared spectroscopy (FT-IR) confirmed that PEGDA monomer successfully located at the molecules of MS and some interesterification reactions occurred between PEGDA and PLLA. The ductility of PLLA materials were significantly improved, for example, the elongation of break increased to 298% at the optimum PLLA/MS/PEGDA content. Dynamic mechanical thermal analysis (DMTA) demonstrated the glass transition temperature of blends decreased with the contents of MS/PEGDA increasing. The differential scanning calorimeter (DSC) results revealed that cold crystallization temperature and melting temperature of blends were decreased with the augment of the contents of MS/PEGDA. Wide angle X-ray diffraction (WARD) and DSC certified that a high crystalline article was obtained through practical extrusion process, which could propagate shear yielding deformation to dissipate energy during tensile fracture. Scanning electron microscope (SEM) demonstrated that the blends with PEGDA did not exhibit a visible phase-separated morphology from cryogenic fractured surfaces compared with the blend without PEGDA.

Bioinspired approach to enhance mechanical properties of starch based nacre-mimetic nanocomposite.

In this work, a facile biomimetic method was proposed to enhance the interfacial adhesion between layered clay and polymer matrix inspired by strong adhesion of mussel adhesive proteins. Montmorillonite (MMT) was coated with a thin layer of polydopamine (PDA) through self-polymerization of dopamine (DA) and subsequently assembled with corn starch (CS) to generate CS/MMT-DA nanocomposite. FTIR, XPS, SEM and XRD results demonstrated that PDA coating benefited not only the intercalation and dispersion of the modified MMT (MMT-DA) in the polymer matrix but also the strong interfacial adhesion between filler and matrix. The tensile strength of CS/MMT-DA nanocomposites was largely enhanced by increasing the amount of DA or polymerization time. This work can largely expand the application of MMT and provide a new idea for preparing high performance starch nanocomposites.

Fabrication and characterization of starch-based nanocomposites reinforced with montmorillonite and cellulose nanofibers.

In this study, one-dimensional (1D) cellulose nanofibers (CNFs) were used to stabilize the dispersion of two-dimensional (2D) montmorillonite (MMT) plates in aqueous system. Then the prepared MMT/CNF solution was simultaneously merged into water soluble corn starch (CS) to obtain CS/MMT/CNF composite freestanding films through a casting method. The reinforcing effect from building blocks of MMT and CNF, interfacial interactions of hydrogen and covalent bonding together led to enhanced tensile strength and Young's modulus, reduced moisture susceptibility and increased transparency of the ternary CS nanocomposites. These extraordinary properties of the ternary nanocomposites clearly point towards a new strategy for designing and fabricating high-performance starch-based nanocomposites by using binary fillers with different geometric shapes and aspect ratio. This kind of ternary nanocomposite can be widely used in food packing and preservation as a biodegradable and green film.

Augmenting Intrinsic Fenton-Like Activities of MOF-Derived Catalysts via N-Molecule-Assisted Self-catalyzed Carbonization.

To overcome the ever-growing organic pollutions in the water system, abundant efforts have been dedicated to fabricating efficient Fenton-like carbon catalysts. However, the rational design of carbon catalysts with high intrinsic activity remains a long-term goal. Herein, we report a new N-molecule-assisted self-catalytic carbonization process in augmenting the intrinsic Fenton-like activity of metal-organic-framework-derived carbon hybrids. During carbonization, the N-molecules provide alkane/ammonia gases and the formed iron nanocrystals act as the in situ catalysts, which result in the elaborated formation of carbon nanotubes (in situ chemical vapor deposition from alkane/iron catalysts) and micro-/meso-porous structures (ammonia gas etching). The obtained catalysts exhibited with abundant Fe/Fe-Nx/pyridinic-N active species, micro-/meso-porous structures, and conductive carbon nanotubes. Consequently, the catalysts exhibit high efficiency toward the degradation of different organic pollutions, such as bisphenol A, methylene blue, and tetracycline. This study not only creates a new pathway for achieving highly active Fenton-like carbon catalysts but also takes a step toward the customized production of advanced carbon hybrids for diverse energy and environmental applications.

Effect of hyperbranched poly(trimellitic glyceride) with different molecular weight on starch plasticization and compatibility with polyester.

Hyperbranched poly(trimellitic glyceride) (PTG) plasticizers for starch were prepared by using trimellitic anhydride and glycerol as raw materials in a simple one-step synthesis. The structure and branching degree of PTGs were confirmed by Fourier transformed infrared, gel permeation chromatography and 1H nuclear magnetic resonance. The PTGs as plasticizers were composited with maize starch (S) via cooking and film formation. The structure and mechanical, thermal properties of the plasticized starch composites, and its adhesion to cotton and polyester yarns were studied in details. Results indicated that the PTG/S composites had better mechanical property and thermal stability, and lower moisture absorption than glycerol/starch (GLY/S) with the same content (w/w). With the increase in PTG molecular weight, elongation at break of PTG/S film decreased and tensile strength increased, and moisture absorption of PTGs/S reduced. In addition, PTGs/S had a better effect on adhesion to cotton and polyester yarns than GLY/S.

Structure and properties of urea-plasticized starch films with different urea contents.

Films of thermoplastic starch (TPS) plasticized with different contents of urea were prepared by using a solution casting method. Scanning electron microscopy, X-ray diffraction and IR spectroscopy were used to characterize structures of the TPS films, respectively. Water vapor sorption isotherms and tensile properties of the films were determined. TPS films showed more smooth and transparent in appearance and less B-type crystallinity than the starch film without urea. The effect of urea content on the structure and behavior of the TPS film could be divided in three stages: (1) below urea 10% where urea interacted with starch via H-bonding and the films showed an antiplasticization effect, (2) from urea 10% to 30% where an apparent plasticization effect appeared on the starch because of free urea molecules as the effective plasticizer, and (3) a macroscopic phase separation occurred due to supersaturation of urea when urea content was more than 30%.

[Chromaticity analysis for colorants in dye-based ink-jet ink].

For ink-jet color inks used for the well-known printers, taking Canon, EPSON, HEWLETT PACKARD and LEXMARK as samples, transmittances of the ink solutions were determined, and then the chromaticity analyses were made, in order to calculate the tristimulus values and the chromatic coordinate of each color sample. Also, the gamuts, chroma values, dominant wavelengths and complementary wavelengths were obtained by using the chromatic method for the samples. In this paper, an empirical formula was suggested for the relationship between the complementary wavelengths of the three primary colors: lambda compl, M approximately equal 10/9 (lambda compl, Y) + 10 and lambda compl, M approximately equal 10/9 (lambda compl, Y) - 20. It was found that the empirical formula is well suited for matching the complementary wavelengths of the three primary colors for ink sets of the samples studied.