Data on chemical composition of coffee husks and lignin microparticles as their extracted product.

Coffee husks are an abundant and underutilized biomass waste released from coffee production. Experimental analysis showed that coffee husks consisted of 39.2 ± 0.2 wt% cellulose, 12.6 ± 0.1 wt% hemicellulose, 23.3 ± 0.1 wt% Klason lignin, 2.9 ± 0.4 wt% acid-soluble lignin, 8.7 ± 0.2 wt% extractives, and 9.5 ± 0.2 wt% ash. Moreover, different minor elements, including K, Ca, Mg, Al, Fe, Ti, S, and Si, were found. Subsequently, coffee husks were used for the extraction of lignin using an alkaline treatment. As a result, lignin microparticles were formed with a relatively uniform size of 0.55 ± 0.11 mm. Altogether, the current article provided useful data for the valorization of coffee husks and the primary properties of lignin microparticles for further use.

Dermal tissue penetration of in-plane silicon microneedles evaluated in skin-simulating hydrogel, rat skin and porcine skin.

Recently, microneedle-based sensors have been introduced as novel strategy for in situ monitoring of biomarkers in the skin. Here, in-plane silicon microneedles with different dimensions and shapes are fabricated and their ability to penetrate skin is evaluated. Arrays with flat, triangular, hypodermic, lancet and pencil-shaped microneedles, with lengths of 500-1000 µm, widths of 200-400 µm and thickness of 180-500 µm are considered. Fracture force is higher than 20 N for all microneedle arrays (MNA) confirming a high mechanical stability of the microneedles. Penetration force in skin-simulating hydrogels, excised rat abdominal skin and porcine ear skin is at least five times lower than the fracture force for all MNA designs. The lowest force for skin penetration is required for triangular microneedles with a low width and thickness. Skin tissue staining and histological analysis of rat abdominal skin and porcine ear skin confirm successful penetration of the epidermis for all MNA designs. However, the penetration depth is between 100 and 300 µm, which is considerably lower than the microneedle length. Tissue damage estimated by visual analysis of the penetration hole is smallest for triangular microneedles. Penetration ability and tissue damage are compared to the skin prick test (SPT) needle applied in allergy testing.

Magnetic Activated Carbon from ZnCl2 and FeCl3 Coactivation of Lotus Seedpod: One-Pot Preparation, Characterization, and Catalytic Activity towards Robust Degradation of Acid Orange 10.

Lotus seedpods (LSPs) are an abundant and underutilized agricultural residue discarded from lotus seed production. In this study, ZnCl2 and FeCl3 coactivation of LSP for one-pot preparation of magnetic activated carbon (MAC) was explored for the first time. X-ray diffraction (XRD) results showed that Fe3O4, Fe0, and ZnO crystals were formed in the LSP-derived carbon matrix. Notably, transmission electron microscopy (TEM) images showed that the shapes of these components consisted of not only nanoparticles but also nanowires. Fe and Zn contents in MAC determined by atomic absorption spectroscopy (AAS) were 6.89 and 3.94 wt%, respectively. Moreover, SBET and Vtotal of MAC prepared by coactivation with ZnCl2 and FeCl3 were 1080 m2/g and 0.51 cm3/g, which were much higher than those prepared by single activation with FeCl3 (274 m2/g and 0.14 cm3/g) or ZnCl2 (369 m2/g and 0.21 cm3/g). MAC was subsequently applied as an oxidation catalyst for Fenton-like degradation of acid orange 10 (AO10). As a result, 0.20 g/L MAC could partially remove AO10 (100 ppm) with an adsorption capacity of 78.4 mg/g at pH 3.0. When 350 ppm H2O2 was further added, AO10 was decolorized rapidly, nearly complete within 30 min, and 66% of the COD was removed in 120 min. The potent catalytic performance of MAC might come from the synergistic effect of Fe0 and Fe3O4 nanocrystals in the porous carbon support. MAC also demonstrated effective stability and reusability after five consecutive cycles, when total AO10 removal at 20 min of H2O2 addition slightly decreased from 93.9 ± 0.9% to 86.3 ± 0.8% and minimal iron leaching of 1.14 to 1.19 mg/L was detected. Interestingly, the MAC catalyst with a saturation magnetization of 3.6 emu/g was easily separated from the treated mixture for the next cycle. Overall, these findings demonstrate that magnetic activated carbon prepared from ZnCl2 and FeCl3 coactivation of lotus seedpod waste can be a low-cost catalyst for rapid degradation of acid orange 10.

Pyrolytic carbon resonators for micromechanical thermal analysis.

Thermal analysis is essential for the characterization of polymers and drugs. However, the currently established methods require a large amount of sample. Here, we present pyrolytic carbon resonators as promising tools for micromechanical thermal analysis (MTA) of nanograms of polymers. Doubly clamped pre-stressed beams with a resonance frequency of 233 ± 4 kHz and a quality factor (Q factor) of 800 ± 200 were fabricated. Optimization of the electrical conductivity of the pyrolytic carbon allowed us to explore resistive heating for integrated temperature control. MTA was achieved by monitoring the resonance frequency and quality factor of the carbon resonators with and without a deposited sample as a function of temperature. To prove the potential of pyrolytic carbon resonators as thermal analysis tools, the glass transition temperature (T g) of semicrystalline poly(L-lactic acid) (PLLA) and the melting temperature (T m) of poly(caprolactone) (PCL) were determined. The results show that the T g of PLLA and T m of PCL are 61.0 ± 0.8 °C and 60.0 ± 1.0 °C, respectively, which are in excellent agreement with the values measured by differential scanning calorimetry (DSC).