Laminar N-Doped Carbon Materials from a Biopolymer for Use as a Catalytic Support for Hydrodechlorination Catalysts

Nitrogen-doped porous carbons were prepared using a chitosan biopolymer as both a carbon and nitrogen precursor and metallic salts (CaCl2 and ZnCl2-KCl) as a templating agent with the aim of evaluating their performance as catalyst supports. Mixtures of chitosan and templating salts were prepared by simple grinding subjected to pyrolysis and finally washed with water to remove the salts. The resulting materials were characterized, showing that homogeneous nitrogen doping of carbon was achieved (7–9% wt.) thanks to the presence of a nitrogen species in the chitosan structure. A lamellar morphology was developed with carbon sheets randomly distributed and folded on themselves, creating slit-shaped pores. Substantial porosity was observed in both the micropore and mesopore range with a higher surface area and microporosity in the case of the materials prepared by ZnCl2-KCl templating and a larger size of mesopores in the case of ZnCl2. Catalysts with well-dispersed Pd nanoparticles (around 10 nm in diameter size) were synthesized using the chitosan-based carbons obtained both by salt templating and direct chitosan pyrolysis and tested in the aqueous phase hydrodechlorination of 4-chlorophenol. The fast and total removal of 4-chlorophenol was observed in the case of catalysts based on carbons obtained by templating with CaCl2 and ZnCl2-KCl in spite of the low metal content of the catalysts (0.25% Pd, wt.).

Investigation of Dynamic Recrystallization Phenomenon in Drawn Ti-6Al-4V Alloy

The microstructure evolution during the drawing process of Ti-6Al-4V alloy with a lamellar morphology as an initial microstructure was investigated. Microstructure analysis on specimens with a different reduction ratio supported by 2D-drawing process simulation using DEFORMTM was utilized to examine the deformed state and microstructure behavior of the alloy. Dynamic recrystallization (DRX) phenomenon on the high reduction ratio (52.7%) was achieved fine equiaxed grain. A Zenner-Holllomon calculation using temperature and strain rates was also conducted to evaluate the DRX. Furthermore, a higher drawing reduction ratio attributed to a high fraction of kinked lamellar, which DRX occurred in the shear band and the regions of broken lath or kinked.

Metallopolymer-block-oligosaccharide for sub-10 nm microphase separation

The novel high-χ BCPs comprising poly(vinyl ferrocene) and oligosaccharides formed hexagonal cylinder morphology with d values of ∼8 nm. Lamellar morphology with d values of ∼9 nm was also realized by mixing these polymers and glucose.

Accounting for π–π stacking interactions in the mesoscopic models of conjugated polymers

Accounting for π–π interactions between conjugated polymer molecules via dynamic bonds allows their self-assembly into a lamellar morphology with π–π stacks.

Flexible nanocellulose-based aerogel with loading of modified UiO-66 as efficient adsorbent for removal of heavy metal ions

Currently, preparation of outstanding adsorbents has attracted public concern in environmentally friendly and sustainable pollutant redress. Herein, we report a directional freeze-drying method to prepare a flexible and reusable adsorbent through introducing modified metal-organic framework material (UiO-66-EDTA) into cellulose nanofibers (CNF) aerogel. By controlling the concentration of crosslinkable carboxymethy cellulose (CMC) solution, we produced aerogels with different pore structures, fibrillar, columnar and lamellar morphology. The obtained UiO-66-EDTA/CNF/CMC aerogel (U-EDTACCA) showed excellent adsorption performance for total 9 types of heavy metal ions with the removal efficiency reaching 91%. Moreover, the aerogels could retain 88% of its original shape after 5 times cycling. The aerogel may be appropriate material for adsorbing heavy metal ions.

Hydrothermal Synthesis of SnO2 Nanorod as Anode Materials for Lithium-Ion Battery

In this study, SnO2 nanorods are successfully prepared by simple template-free hydrothermal method without surfactant. SnO intermediate with lamellar morphology is first formatted by hydrothermal method and SnO2 nanorods are obtained after calcinations. The results of XRD characterization show that lamellar structured SnO intermediate has preferred orientation in 0 0 1 direction. According to supposed mechanism during formation process of SnO2 nanorods, tiny crystal nucleus of Sn(OH)2 and a bit of SnCO3 are generated from SnCl2 and urea. Then the crystal nucleus gather together to form a nanorod. With continued reaction, nanorods gather together to form sheets and the sheets grow up to lamellar morphology and the intermediate decomposes into SnO because of the hydrothermal process. The SnO intermediate convert to SnO2 with sheets breaking to nanorods after calcination. The results of galvanostatic cell cycling show that SnO2 particle has high specific discharge capacity capacity. This experiment of SnO2 nanorod preparation provides us an effective way of easy processing, low cost, and more environmentally synthesis strategy to synthesize SnO2 nanorods.