Incorporation of Different Metal Ion for Tuning Color and Enhancing Antioxidant Activity of Curcumin/Palygorskite Hybrid Materials

Curcumin is one of the dietary dyes extracted from turmeric and used for prevention and treatment of various illnesses. However, the low bioavailability and poor stability of curcumin limits its relevant applications. Therefore, different metal ions including Cu2+, Zn2+, Mg2+, Al3+, or Fe3+ were incorporated to tune the color, enhance the environmental stability and antioxidant activity of curcumin in the presence of palygorskite in this study. The as-prepared samples were studied using X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, Zeta potential, and transmission electron microscopy. In addition, the density functional theory calculation was also performed to explore the possible interaction among metal ions, curcumin and palygorskite. It was found that the color changing and stability enhancing were ascribed to the curcumin-metal ions coordination as well as chemical interactions between curcumin-metal complex and palygorskite. Moreover, the as-prepared composites showed more excellent color, thermal stability, antioxidant activity, and fluorescence properties than that of the curcumin/palygorskite composites due to the presence of metal ions. The finding of this investigation may contribute to developing the multifunctional composites with different colors and good antioxidant activity for relevant applications based on curcumin and palygorskite.

Improved method of manufacturing carbon nanotube infused multifunctional 3D woven composites

This research work aimed to develop smart multifunctional composites via a process for uniformly dispersing carbon nanotubes (CNT) on an orthogonal three-dimensional (3D) woven glass fabric with minimised filtering effect. These smart composites could detect strain under tensile and flexural loading by the piezoresistive response of the infused CNT network. Conventional vacuum assisted resin transfer moulding was modified to control the infusion of 0.25 wt% CNT on the 3D woven glass fabric by varying the vacuum pressure. Results showed that at 101.3 kPa vacuum pressure, the CNT percolated through the thickness of the orthogonal 3D woven glass fabric while being marginally filtered by the fibres and were suitable for sensing tensile strain, whereas at 30.4 kPa, the CNT were deposited only on the surface of the fabric preform without getting filtered and were suitable for sensing flexural strain.

Mechanical Performance and Applications of CNTs Reinforced Polymer Composites—A Review

Developments in the synthesis and scalable manufacturing of carbon nanomaterials like carbon nanotubes (CNTs) have been widely used in the polymer material industry over the last few decades, resulting in a series of fascinating multifunctional composites used in fields ranging from portable electronic devices, entertainment and sports to the military, aerospace, and automotive sectors. CNTs offer good thermal and electrical properties, as well as a low density and a high Young’s modulus, making them suitable nanofillers for polymer composites. As mechanical reinforcements for structural applications CNTs are unique due to their nano-dimensions and size, as well as their incredible strength. Although a large number of studies have been conducted on these novel materials, there have only been a few reviews published on their mechanical performance in polymer composites. As a result, in this review we have covered some of the key application factors as well as the mechanical properties of CNTs-reinforced polymer composites. Finally, the potential uses of CNTs hybridised with polymer composites reinforced with natural fibres such as kenaf fibre, oil palm empty fruit bunch (OPEFB) fibre, bamboo fibre, and sugar palm fibre have been highlighted.

One-Step Synthesis of Ribonucleases A–Ag Nanocomposites as Fluorescent Nanodrugs for in vivo Delivery

Proteins and enzymes with potential therapeutic function have been widely used in drug delivery. Meanwhile, nanocrystals (NCs) have showed their advantage as in vivo fluorescent indicators. Combining of these two kinds of materials can result in multifunctional composites. Here, a one-step synthesis of protein–NCs nanocomposites with near infrared (NIR) fluorescence and efficient therapeutic function was developed. Ag NCs were formed using ribonucleases A (RNase A) enzyme as a stabilizer. Meanwhile, the RNase A with long chain rapped around Ag NCs and formed RNase A–Ag nanocomposites. The nanocomposites remained both the NIR fluorescence of Ag NCs and antitumor activity of RNase A. The inhibition of the growth of tumor cells by the nanocomposites was confirmed. This study developed an efficient drug delivery system through combination of the protein and nanoparticles, which had potential clinical application in the future.

Conductive Metakaolin Geopolymer with Steel Microfibres​

Research of alkali-activated materials and geopolymers suggests their increased ability to transfer the electric charge thus indicating their suitability for self-sensing and other multifunctional composites. In this paper, the electrical properties of metakaolin geopolymer are enhanced by the incorporated steel microfibres that also improve the mechanical and fractural properties of the composite. Selected electrical properties of metakaolin geopolymer mortars with steel microfibres (up to 30 % of metakaolin wt.) were assessed via impedance spectroscopy analysis and followed by testing their compressive and flexural strength. Mercury intrusion porosimetry and SEM imaging enabled to characterize the binder microstructure and quality of fibre-matrix bonding.