Investigation of the features of the porous morphology of anodic alumina films at the initial stage of anodization

The work is devoted to the study of the porous structure formation of anodic alumina films at the initial stage of aluminium anodizing. SEM images of the surface morphology of the oxalic acid anodic films were analyzed. It was shown that at the initial stage, both major and minor pores are formed, the diameter ratio of which is about 1.16 and does not depend on the anodizing voltage. The results obtained indicate that the minor pores in the anodic films are located inside hexagonal cells composed of the major pores.

Optimization and Scale-up Methodology in Preparing Microsponge Loaded with 5-Fluorouracil (5-FU).

The present investigation aims at developing models by response surface methodology (FCCCD) followed by the scale-up method in preparing control release microsponge particles loaded with 5- fluorouracil, a drug used to treat actinic keratosis and colon cancer, and producing a new Dermal Delivery System. The polymer-based (ethyl cellulose and eudragit RS 100) microsponge particles were prepared by the w/o/w double emulsification method. The optimized product was formed with the combination of independent variables levels: polymer (600 mg), stirring speed (1198 rpm) and surfactant (2% w/v), yielding responses as yield (~63.6257%), the average size of particles (~151.563 µm), entrapment efficiency (~75.319 %) and drug release in 8hr (~75.75%), with desirability value of 0.737. The products showed similar responses as obtained in scale-up work. FT-IR, DSC and SEM studies confirmed the drug's compatibility with polymers and porous morphology. Finally, gel embedded optimised product showed shear-thinning rheological property, ideal for drug release from the thixotropic gel.

Flexible iron oxide supercapacitor electrodes by photonic processing

We report the preparation of flexible and nano-porous iron oxide-reduced graphitic oxide (Fe2O3–rGO) electrodes using a novel photonic processing method. Due to this unique technique, high-temperature thermal processing could be accomplished on inexpensive and low-temperature substrates instantaneously as opposed to longer processing times of conventional thermal processing. The nano-porous morphology of the electrode not only accommodates the volume changes of the electrode but also facilitates the transport of the electrolyte ions into the electrodes. The as-prepared electrode showed excellent electrochemical performance with an initial specific capacitance of 179 F/g at 2 A/g. Moreover, it exhibited excellent specific capacitance retention after 5000 cycles (70%), revealing its superior cyclic stability. Along with having specific capacitance comparable to that of rigid electrodes, the as-prepared electrode is bendable and lightweight, signifying its potential application in foldable and wearable consumer electronic devices which require continuous energy supply while going through physical deformation. Graphic abstract

Study of The Variation of Activating Agents on Specific Capacitance Values on The Synthesis of Supercapacitor Electrodes Based on Pepper Peel Waste

The by-product of pepper production in Bangka Belitung is the waste of pepper skin. This waste tends to be untapped and thrown away so that it can disrupt the environmental ecosystem. One of the efforts to utilize pepper skin waste is processing it into activated carbon as the base material for supercapacitor electrodes. The initial stage of the synthesis was carried out by a pre-carbonization process on a sample of dry and clean pepper peel waste. Furthermore, the sample is chemically activated using a chemical activator and also physical activation at a temperature of 700ºC in N2 gas flow conditions. The activated carbon resulting from the activation is then molded into electrode plates in the form of pellets with a diameter of 1 cm. The electrode plates were characterized using a scanning electron microscope-energy dispersive x-ray (SEM-EDX) to determine morphology and cyclic voltammetry (CV) to determine the specific capacitance value. SEM test results show that the electrode sample has porous morphology and CV results show that the sample activated using the KOH activator has a specific capacitance value of 15.20 F/g. These results indicate that the activated carbon synthesized from the waste of pepper peel can be used as a supercapacitor electrode material and also a solution for overcoming the negative effects of pepper skin waste.

Synthesis of Ambient Cured GGBFS Based Alkali Activated Binder Using a Sole Alkaline Activator: A Feasibility Study

Utilisation of industrial waste-based material to develop a novel binding material as an alternative to Ordinary Portland Cement (OPC) has attracted growing attention recently to reduce or eliminate the environmental footprint associated with OPC. This paper presents an experimental study on the synthesis and evaluation of alkali activated Ground granulated blast furnace slag (GGBFS) composite using a NaOH solution as an alkaline activator without addition of silicate solution. Different NaOH concentrations were used to produce varied GGBFS based alkali activated composites that were evaluated for Uncofined Compressive Strength (UCS), durability, leachability, and microstructural performance. Alkali activated GGBFS composite prepared with 15 M NaOH solution at 15% L/S ratio achieved a UCS of 61.43 MPa cured for 90 days at ambient temperatures. The microstructural results revealed the formation of zeolites, with dense and non-porous morphology. Alkali activated GGBFS based composites can be synthesized using a sole alkaline activator with potential to reduce CO2 emission. The metal leaching tests revealed that there are no potential environmental pollution threats posed by the synthesized alkali activated GGBFS composites for long-term use.

Open Porous Composite Monoliths for Biomedical Applications via Photocrosslinking of Low Internal Phase Nano-Emulsion Templates

Highly cross-linked polyethylene glycol monoliths (HCPEG) with interconnected micro and nanoporosity are produced via photo-crosslinking of low internal phase emulsions (LIPE). Unlike previous works, this approach allows the pre-processing functionalization of both polymer matrix and porosity by loading both phases of the emulsion template with several active fillers, such as enzymes, semiconductive polymers, and metallic nanostructures. Importantly, both polymer matrix and porosity of the resulting composite HCPEG monoliths show neither serious cross-contamination nor morphological alterations. All in all, this material behaves like a network of nano/micro flasks embedded into a permeable media. Mechanical and dielectric properties of these composites HCPEG monoliths can be tuned by varying the content of fillers. Since these composite materials are produced by photo-crosslinking of LIPEs, they can be easily and rapidly processed into complex shapes like microneedles arrays through replica molding without detrimental modifications of the porous morphology. In principle, the proposed strategy allows us to fabricate medical devices. As proof of concept, we embedded glucose oxidase enzyme in the nanoporosity and the resulting composite porous material retained the catalytic activity towards the oxidation of glucose.

Starch-Based Super Water Absorbent: A Promising and Sustainable Way to Increase Survival Rate of Trees Planted in Arid Areas

This research aimed to scale up the production of starch-based super water absorbent (SWA) and to validate the practical benefits of SWA for agricultural applications. SWA was successfully prepared in an up-scaling production by radiation-induced graft polymerization of acrylic acid onto cassava starch. Chemical characterization by FTIR and thermal characterization by TGA showed results that differentiated starting materials from the prepared SWA, thus confirming effective preparation of starch-based SWA via radiation-induced graft polymerization. SEM results visibly revealed a highly porous morphology of the synthesized SWA, substantiating its high swelling ability. Results from the field tests, performed for two seasons, revealed that the prepared SWA was able to increase the survival rate of young rubber trees planted in arid area by up to 40%, while simultaneously enhancing the growth characteristics of the young rubber trees.