Amine-functionalized porous silica production via ex- and in-situ method using silicate precursors as a selective adsorbent for CO2 capture applications.

A comparison of the amine-modified silica particle's characteristics via ex- and in-situ routes and their application as a CO2 gas adsorbent is reported. Modifying silica particles via ex-situ involves two separate steps: forming porous silica particles with sodium lauryl sulfate (SLS) as a template and impregnation using ultrasound assistance. In contrast to ex-situ modification, in-situ modification of silica particles is carried out in one step by mixing directly between the silica source and the modifying agent. Controlling the characteristics of modified silica particles via in-situ is carried out by adding an SLS template removed simultaneously with particle formation to increase the surface area and porosity. Increasing the SLS template concentration shows a linear relationship between increasing particle surface area and amine loading. However, two different modification routes exert a direct influence on aminopropyl distribution. Silanization via in-situ which involves a simultaneous condensation reaction produces a higher amine loading reaching 1.2845 mmol/g of silica than via ex-situ which is only 0.9610 mmol/g of silica. The amount of aminopropyl that can be grafted on the silica surface shows a linear relationship to the quantity of CO2 gas adsorption capacity. Amine-modified silica particles obtained the highest adsorption capability via the in-situ route with an SLS 3 CMC template of 2.32 mmol/g silica at an operating pressure of 6 bar.

Nano Uncaria gambir as Chemopreventive Agent Against Breast Cancer.

Background: Breast cancer is one of the main causes of death in women. Uncaria gambir is an Indonesian herbal plant that can be used as an anti-cancer. However, herbal medicines have low bioavailability, which affects their bioactivity. Nanoencapsulation can increase bioavailability and stability of bioactive compounds in herbal medicines. Purpose: This recent finding tried to unravel anti-cancer and chemopreventive of U. gambir nano-encapsulated by Na-alginate. Study Design: U. gambir bioactive compounds were isolated and characterized using UV-Vis spectrometer, FTIR, NMR and HR-MS. U. gambir extract was nanoencapsulated using Na-alginate. Anti-cancer effect was assessed by MTT assay towards T47D cell. Meanwhile, a chemopreventive analysis was carried out in breast cancer mice-induced benzo[α]pyrene. The healthy mice were divided into 8 groups comprising control and treatment. Results: Elucidation of U. gambir ethyl acetate extract confirmed high catechin content, 89.34% (w/w). Successful nanoencapsulation of U. gambir (G-NPs) was indicated. The particle size of G-NPs was 78.40 ± 12.25 nm. Loading efficiency (LE) and loading amount (LA) of G-NPs were 97.56 ± 0.04% and 32.52 ± 0.01%, respectively. G-NPs had an EC50 value of 10.39 ± 3.50 µg/mL, which was more toxic than the EC50 value of extract towards the T47D cell line. Administration of 200 mg/kg BW G-NPs to mice induced by benzo[α]pyrene exhibited SOD and GSH levels of 13.69 ng/mL and 455.6 ng/mL. In addition, the lowest TNF-α level was 27.96 ng/mL. A dose of 100 mg/kg BW G-NPs could best increase CAT levels by 7.18 ng/mL. There was no damage or histological abnormalities found in histological analysis of the breast tissue in the group given 200 mg/kg BW G-NPs.

TEMPO-oxidized cellulose nanofiber (TOCN) decorated macroporous silica particles: Synthesis, characterization, and their application in protein adsorption.

Effective protein adsorption has attracted attention for broad application in the biomedical field. In this study, we introduce the synthesis of a TEMPO-oxidized cellulose nanofiber (TOCN) decorated macroporous SiO2 (TOCN@macroporous SiO2) particle and its protein adsorption performance. The TOCN@macroporous SiO2 particles have a unique cellulose nanofiber network structure on the macroporous, highly-negative zeta potential (-62 ±â€¯2 mV) and high surface area (30.8 m2/g) for dried-state cellulose based particles. These characteristics provide sites that are rich in electrostatic interaction to exhibit an outstanding adsorption capacity of lysozyme (1865 mg/g). Furthermore, the TOCN@macroporous SiO2 particles have remarkably high reusability (>90% adsorption capacity) and good release of adsorbate (>80%) after 10 times of use. The material proposed in this paper has the potential for application in drug delivery, protein adsorption, biosensors, and other biomedical fields.

Hexagonal hollow silica plate particles with high transmittance under ultraviolet-visible light.

Creating hollow structures is one strategy for tuning the optical properties of materials. The current study aimed to increase the optical transmittance of silica (SiO2) particles. To this end, hexagonal-shaped hollow silica plate (HHSP) particles were synthesized from tetraethyl orthosilicate (TEOS) and zinc oxide (ZnO) template particles, using a microwave-assisted hydrothermal method. The size and shell thickness of the HHSP particles could be adjusted by using different TEOS/ZnO molar ratios and different ZnO template sizes, respectively. The optical transmittance of the HHSP particles depended on the shell thickness and particle size. The highest transmittance was 99% in the ultraviolet and visible region (300-800 nm) and was exhibited by HHSP particles with the thinnest shell thickness of 6.3 nm. This transmittance was higher than that exhibited by spherical hollow silica particles with a similar shell thickness. This suggested morphology-dependent transmittance for the semiconducting material. These preliminary results illustrate the promising features of the HHSP particles and suggest their potential application in future transparent devices.

Enhanced Electrocatalytic Activity of Pt/3D Hierarchical Bimodal Macroporous Carbon Nanospheres.

Proton exchange membrane fuel cells require electrocatalysts with a high platinum (Pt) loading, large active surface area, and favorable hydrodynamic profile for practical applications. Here, we report the design of three-dimensional hierarchical bimodal macroporous carbon nanospheres with an interconnected pore system, which are applied as an electrocatalyst support. Carbon-supported Pt (Pt/C) catalysts were prepared by aerosol spray pyrolysis followed by microwave chemical deposition. The hierarchical porous structures not only increased the dispersion of Pt nanoparticles but also improved catalytic performance. A hierarchical bimodal macroporous Pt/C catalyst with a mixture of 30 and 120 nm size pores showed the best performance. The electrochemical surface area and mass activity values of this support were 96 m2 g-1-Pt and 378 mA mg-1-Pt, respectively at a Pt loading of 15 wt %.

Production of morphology-controllable porous hyaluronic acid particles using a spray-drying method.

Hyaluronic acid (HA) porous particles with controllable porosity and pore size, ranging from 100 to 300 nm, were successfully prepared using a colloidal templating and spray-drying method. HA powder and polystyrene latex (PSL) particles, which were used as the precursor and templating agent, respectively, were mixed in aqueous solution and spray-dried using a two-fluid nozzle system to produce HA and PSL composite particles. Water was evaporated during spray-drying using heated air with a temperature of 120 degrees C. This simple process was completed within several seconds. The prepared particles were collected and washed with an organic solvent to dissolve the PSL templating agent. The porosity and pore size of the resulting particles were easily controlled by changing the initial mass ratio of precursor to templating agent, i.e., HA to PSL, and by altering the size of the PSL template particles.