Plasticizer migration in bloodmeal‐based thermoplastics

Tri‐ethylene glycol (TEG) is an effective plasticizer for many protein‐based thermoplastics because of its low volatility, however, partial miscibility with the protein matrix may still lead to some phase separation. Spatial variation of TEG concentration in bloodmeal‐based thermoplastics as a result of processing was investigated using synchrotron‐based FT‐IR micro‐spectroscopy. Although TEG forms strong hydrogen bonding with proteins, for the protein to fold into β‐sheets bound plasticizer must be released. TEG can then migrate, pooling into localized areas, rich in plasticizer. Further heating causes further migration towards the edge of plasticized bloodmeal particles where the TEG may evaporate. Thermo‐gravimetric analysis confirmed that loss of TEG by evaporation may occur at 120°C, given enough time for diffusion. Efficient mixing combined with a short residence time at elevated temperature mean significant plasticizer loss is unlikely during processing. However, it does limit long‐term use at elevated temperatures. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39969.     

Influence of 4ZnO–B2O3 Addition on Dielectric Properties and Microstructures of Barium Strontium Titanate

This study investigates the effect of 4ZnO–B₂O₃ on the sintering behavior, dielectric properties, and microstructures of Ba_0.6Sr_0.4TiO₃ (BST) ceramics. These ceramics were sintered in air at temperatures ranging from 900°C to 1080°C. BST ceramics with 4ZnO–B₂O₃ addition can be sintered to a theoretical density higher than 95% at 1050°C. A secondary phase (Ba₂ZnTi₅O₁₃) is produced in the BST ceramics during 4ZnO–B₂O₃ addition. Compositional analysis using TEM-EDX of the BST ceramics with 3 wt% 4ZnO–B₂O₃ revealed that the Zn ion is generally located at the triple points. This result indicates that BaO, TiO₂, and ZnO form a liquid phase that acts as a secondary phase at the lower sintering temperatures. The amount of secondary phase was observed to increase as the amount of 4ZnO–B₂O₃ additives increased. In addition, the original Ba_0.6Sr_0.4TiO₃ phase was shifted to the Ba_0.5Sr_0.5TiO₃ phase by the addition of 3 wt% 4ZnO–B₂O₃ at 1050°C. The Ba_0.6Sr_0.4TiO₃ ceramic with 2 wt% 4ZnO–B₂O₃ sintered at 1050°C in air for 2 h exhibited dielectric properties of ɛ_r=1883 and dissipation loss=0.36%. Moreover, BST with 1 wt% 4ZnO–B₂O₃ addition sintered at 1080°C exhibits dielectric properties of ɛ_r=2330, dissipation loss=0.29%, and bulk density >95% of theoretical density.     

Conductive Polymer-Coated 3D Printed Microneedles: Biocompatible Platforms for Minimally Invasive Biosensing Interfaces

Conductive polymeric microneedle (MN) arrays as biointerface materials show promise for the minimally invasive monitoring of analytes in biodevices and wearables. There is increasing interest in microneedles as electrodes for biosensing, but efforts have been limited to metallic substrates, which lack biological stability and are associated with high manufacturing costs and laborious fabrication methods, which create translational barriers. In this work, additive manufacturing, which provides the user with design flexibility and upscale manufacturing, is employed to fabricate acrylic-based microneedle devices. These microneedle devices are used as platforms to produce intrinsically-conductive, polymer-based surfaces based on polypyrrole (PPy) and poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS). These entirely polymer-based solid microneedle arrays act as dry conductive electrodes while omitting the requirement of a metallic seed layer. Two distinct coating methods of 3D-printed solid microneedles, in situ polymerization and drop casting, enable conductive functionality. The microneedle arrays penetrate ex vivo porcine skin grafts without compromising conductivity or microneedle morphology and demonstrate coating durability over multiple penetration cycles. The non-cytotoxic nature of the conductive microneedles is evaluated using human fibroblast cells. The proposed fabrication strategy offers a compelling approach to manufacturing polymer-based conductive microneedle surfaces that can be further exploited as platforms for biosensing.     

Intensifying Heat Using MOF-Isolated Graphene for Solar-Driven Seawater Desalination at 98% Solar-to-Thermal Efficiency

Photothermal materials are crucial for diverse heating applications, but it remains challenging to achieve high energy conversion efficiency due to the difficulty to concurrently improve light absorbance and suppress heat loss. Herein, a zeolitic imidazolate framework-isolated graphene (G@ZIF) nanohybrid is demonstrated that utilizes ultrathin, heat-insulating ZIF layers, and G@ZIF interfacial nanocavity to synergistically intensify light absorbance and heat localization. Under artificial sunlight illumination (≈1 kW m⁻²), the G@ZIF film attains a maximum temperature of 120 °C in an open environment with a 98% solar-to-thermal conversion efficiency. Importantly, the porous ZIF layer allows small molecules/media to enter and access the embedded hot graphene surface for targeted heat transfer in practical applications. As a proof-of-concept, the G@ZIF-based steam generator realizes 96% energy conversion from light to vapor with near-perfect desalination and water purification efficiencies (>99.9%). This design is generic and can be extended to other photothermal systems for advanced solar-thermal applications, including catalysis, water treatments, sterilization, and mechanical actuation.     

Graphene-Based Sorbents for Multipollutants Removal in Water: A Review of Recent Progress

The coexistence of multiple toxic water pollutants (heavy metals, organic dyes, oils, and organic solvents) limits the sustainable supply of clean water worldwide and urges the development of advanced water purification technology that can remove these contaminants simultaneously. Since its discovery, graphene-based materials have gained substantial attention toward development of new-generation sorbents for water purification. Despite several recently published reviews on water purification technology using graphene and its derivatives, there is still a gap in the review considering multiple water-pollutant remediation using advanced graphene materials. In this review, in the first instance, a comparative structure–function–performance relationship between graphene-based sorbents and the multipollutants in water is established. A fundamental correlation is made between the sorption performance for diverse pollutants in water with the more specific adsorption properties (surface area, pore size, type of functional groups, C/O, C/N, and C/S atomic ratio) of advanced graphene sorbents. Second, the underlying interaction mechanisms are uncovered between different classes of water pollutants using single graphene-based sorbents. Third, the rational design of advanced multipollutant sorbents based on graphene is elaborated. The reality, challenges, and opportunities of advanced graphene materials as emerging sorbents for sustainable water purification technology are finally presented in the last section.     

Effect of food to microorganisms (F/M) ratio on biohythane production via single-stage dark fermentation

Hythane is a mixture of hydrogen and methane gases which are generally produced in separate ways. This work studied mesophilic biohythane gas (H₂+CH₄+CO₂) production in a bioreactor via single-stage dark fermentation. The fermentation was conducted in batch mode using mixed anaerobic microflora and food waste and condensed molasses fermentation soluble to elucidate the effects of food to microorganisms (F/M) ratio (ranging from 0.2 to 38.2) on gas production, metabolite variation, kinetics and biohythane-composition indicator performances. The experimental results indicate that the F/M ratio and fermentation time affect biohythane production efficiency with values of peak maximum hydrogen production rate 9.60 L/L-d, maximum methane production rate 0.72 L/L-d, and hydrogen yield (HY) of 6.17 mol H₂/kg COD_added. Depending on the F/M ratios, the H₂, CH₄ and CO₂ biogas components were 10–60%, 5–20% and 35–70%, respectively. Prospects for the further real application for single-stage biohythane fermentation based on the experimental data are proposed. This work characterizes an important reactor operation factor F/M ratio for innovative single-stage dark fermentation.     

Growth and Application of ZnO Nanostructures

Nanostructures are the building blocks of future nanodevices and thus methods for fabricating nanostructures of various materials in various forms are fundamentally important. Among those nanostructures ZnO has received much attention over the past few years due to the wide range of research by many different groups focused on different novel nanostructures with different properties. Although ZnO nanowires have been intensively studied, there are only a few methods that showed promising characteristics for practical applications. Without much effort, it can be grown in many different nanostructure forms, thus allowing various novel devices to be achieved. In this study, we intend to review those methods that enable nanostructure growth to be more controllable and feasible for applications. The methods for fabricating ZnO nanostructures are introduced in the first part. In the second part, the application of those nanostructures are mentioned and explained. Finally, the future realization of nanodevices is discussed.     

Biohydrogen production from soluble condensed molasses fermentation using anaerobic fermentation

Using anaerobic micro-organisms to convert organic waste to produce hydrogen gas gives the benefits of energy recovery and environmental protection. The objective of this study was to develop a biohydrogen production technology from food wastewater focusing on hydrogen production efficiency and micro-flora community at different hydraulic retention times. Soluble condensed molasses fermentation (CMS) was used as the substrate because it is sacchariferous and ideal for hydrogen production. CMS contains nutrient components that are necessary for bacterial growth: microbial protein, amino acids, organic acids, vitamins and coenzymes. The seed sludge was obtained from the waste activated sludge from a municipal sewage treatment plant in Central Taiwan. This seed sludge was rich in Clostridium sp.A CSTR (continuously stirred tank reactor) lab-scale hydrogen fermentor (working volume, 4.0 L) was operated at a hydraulic retention time (HRT) of 3–24 h with an influent CMS concentration of 40 g COD/L. The results showed that the peak hydrogen production rate of 390 mmol H₂/L-d occurred at an organic loading rate (OLR) of 320 g COD/L-d at a HRT of 3 h. The peak hydrogen yield was obtained at an OLR of 80 g COD/L-d at a HRT of 12 h. At HRT 8 h, all hydrogenase mRNA detected were from Clostridium acetobutylicum-like and Clostridium pasteurianum-like hydrogen-producing bacteria by RT-PCR analysis. RNA based hydrogenase gene and 16S rRNA gene analysis suggests that Clostridium exists in the fermentative hydrogen-producing system and might be the dominant hydrogen-producing bacteria at tested HRTs (except 3 h). The hydrogen production feedstock from CMS is lower than that of sucrose and starch because CMS is a waste and has zero cost, requiring no added nutrients. Therefore, producing hydrogen from food wastewater is a more commercially feasible bioprocess.     

Association between PDCD1 Gene Polymorphisms and Risk of Systemic Lupus Erythematosus in Three Main Ethnic Groups of the Malaysian Population

The programmed cell death 1 (PDCD1) gene encodes for the PD-1 (programmed death 1) molecule, which negatively regulates self-reactive T- and B-cells in the maintenance of peripheral tolerance. A previous report had shown the development of lupus-like phenotypes in PD-1-deficient C57BL/6 mice, was suggestive to the role of PDCD1 in predisposing to systemic lupus erythematosus (SLE). Hence, we aimed to investigate the association between PDCD1 and SLE susceptibility in the Malaysian population. A TaqMan-based real-time PCR was employed to screen for PD1.1, PD1.3, PD1.5 and PD1.6 in both SLE and healthy control groups of 200 samples each. The observed frequency for PD1.5C/C genotype was significantly higher in Indian SLE patients and Malay controls (p < 0.01). On the other hand, the PD1.5C/T genotype might predispose the Malays to SLE, but confer a protective effect among the Indians (p < 0.01). The PD1.1, PD1.3 and PD1.6 were, however, not correlated to genetic predisposition of SLE in our Malaysian population. In conclusion, PD1.5 variant was significantly associated to SLE susceptibility in our Malaysian cohort. Our failure in replicating the association between other investigated PDCD1 variants and risk of getting SLE might due to ethnic and geographic variations in the distribution of these genetic variants.