Different Agglomeration Processes Induced by the Varied Interaction of Fe-Fe Analogues with Differently Charged Surfactants

The catalytic activity of Prussian blue analogues (PBAs) is mainly tuned via the control of material sizes and morphologies. However, the shapes and sizes of many PBAs are difficult to control. In this work, a facile approach is demonstrated using differently charged surfactants to tune the catalytic activity of PBAs. Fe-Fe PBAs prepared with non-ionic P123, cationic cetyltrimethylammonium bromide, and anionic sodium dodecyl sulfate are chosen to study the effect of surfactant charges on the catalytic activity. The transesterification of propylene carbonate to dimethyl carbonate by methanol is selected as a model reaction. Owing to the different agglomeration processes of PB particles after modified with differently charged surfactants, significantly varied shapes and sizes were observed. Accordingly, the catalytic activity is greatly varied by adding surfactants. The different catalytic activities may arise from the different behaviors of agglomeration of PB particles after surfactant modification as well as the material size and shape changes. Besides, apparent activation energies for PBs adding different surfactants were derived. Finally, the agglomeration mechanism of PB particles in the presence of differently charged surfactants was proposed.

A novel alginate/gelatin sponge combined with curcumin-loaded electrospun fibers for postoperative rapid hemostasis and prevention of tumor recurrence

Surgical resection of the tumor remains the preferred treatment for most solid tumors at an early stage, but surgical treatment often leads to massive bleeding and residual tumor cells. Therefore, a novel alginate/gelatin sponge combined with curcumin-loaded electrospun fibers (CFAGS) for rapid hemostasis and prevention of tumor recurrence was prepared by using an electrospinning and interpenetrating polymer network (IPN) strategy. The present results show that alginate/gelatin sponge display excellent hemostatic properties and possess more advantages than commercial gelatin hemostasis sponge. More importantly, CFAGS could control the release of curcumin, inducing curcumin to accumulate at the surgical site of the tumor, thereby inhibiting local tumor recurrence in the subcutaneous postoperative recurrence model. In addition, the sponge was safe to implant in the body and did not cause toxicity to normal tissues and organs. This approach represents a new strategy to implant a dual functional sponge at the postoperative site as an adjuvant to the surgical treatment of cancer.

Polypyrrole/Carbon Nanotube Freestanding Electrode with Excellent Electrochemical Properties for High-Performance All-Solid-State Supercapacitors

In this study, a facile and environmentally friendly method was used to prepare a freestanding supercapacitor electrode displaying excellent areal capacitance and good cycle life performance. First, we prepared polypyrrole nanoparticles (PPyNP) through a simple in situ chemical polymerization using the plant-derived material curcumin as a bioavailable template. A PPyNP/f-CNT freestanding composite electrode of high mass loading (ca. 14 mg cm^-2) was prepared after blending the mixtures of the prepared PPyNP and functionalized CNTs (f-CNTs). The performance of the as-prepared material as a supercapacitor electrode was evaluated in a three-electrode setup using aqueous 1 M H₂SO₄ as the electrolyte. The PPyNP/f-CNT freestanding composite electrode exhibited a high areal capacitance of 4585 mF cm^-2 and a corresponding volumetric capacitance of 176.35 F cm^-3 at a current density of 2 mA cm^-2. A symmetric all-solid-state supercapacitor assembled using two identical pieces of PPyNP/f-CNT composite electrodes exhibited maximum areal energy and power density of 129.24 μW h cm^-2 and 12.5 mW cm^-2, respectively. Besides, this supercapacitor device exhibited good cycle life performance, with 79.03% capacitance retention after 10,000 charge/discharge cycles. These results suggest practical applications for these PPyNP/f-CNT freestanding composite electrode-based symmetric all-solid-state supercapacitors.

Cetyltrimethylammonium Bromide (CTAB) Bloated Micelles and Merged CTAB/Bolaamphiphiles Self-Assembled Vesicles toward the Generation of Highly Porous Alumina as Efficacious Inorganic Adsorbents

Herein, in a new approach, highly porous alumina materials (HiPAs) have been synthesized through cetyltrimethylammonium bromide (CTAB) bloated micelles or merged CTAB/dicarboxylic acid vesicular aggregates (di-acids with 8, 10, and 12 carbon atoms) as novel templates and characterized by N₂ sorption, low- and wide-angle XRD (X-ray diffraction), FE-SEM (field emission scanning electron microscopy), TEM (transmission electron microscopy), HR-TEM (high-resolution transmission electron microscopy), DLS (dynamic light scattering), and AFM (atomic force microscopy) analyses. In the absence of dicarboxylic acids, CTAB bloated micelles in ethanol-aqueous solutions were conductive to the formation of mesoporous γ-alumina hollow spheres (HiPA-CT) with high surface area (394 m² g^-1) and ultralarge pore volume (1.8 cm³ g^-1). Notably, merged giant vesicular assemblies formed between dicarboxylic acids and CTAB endowed the mesoporous alumina nanoparticle aggregates with tunable and unprecedented pore features (surface area of 415-735 m² g^-1 and ultrahigh pore volume of 1.37-2.57 cm³ g^-1), in which their pinnacle was obtained via CTAB/10 (HiPA-CT-10). Due to the tailored porosity, the HiPA-CT and HiPA-CT-10 were exploited for ciprofloxacin (CIP) adsorption experiments. The adsorption efficiency attained a climax at pH 6. At CIP concentrations below 1 ppm, 91 and 86% of CIP were removed by HiPA-CT and HiPA-CT-10, respectively. The maximum adsorption capacities of HiPA-CT and HiPA-CT-10 are 120 and 184 mg g^-1, respectively, in which the latter is surpassing those of inorganic antibiotic adsorbents reported so far. The kinetic results showed that the removal of CIP by HiPA-CT was faster due to the presence of macropores and more accessible active sites on mesoporous surfaces. The reusability test was acceptable after eight runs. The results signify that these novel materials have high potential for reducing our environmental concerns.