Journal of Composites and Compounds
Volume:4 Issue: 11, Jun 2022

In this study, two types of ZnO nanostructures (ZnO nanotips and ZnO nanorods) were synthesized through a chemical bath deposition (CBD) method. These two structures were then compared by optical and structural analyses. The result showed the significant effect of ammonia concentration and the preferential etchings along the c axis on the formation of ZnO nanotips (NTs). To improve the absorption, nanostructures were optimized by reflectance analysis. To enhance the optical properties of the optimized sample, reduced graphene oxide (rGO) layers were transferred on the ZnO NTs surface by the electrophoretic deposition (EPD) method. The deposition of rGO layers on ZnO NTs can increment the optical absorption over a wide range of frequencies. The reflectance results showed enhanced adsorption capacity in the case of rGO/ZnO NTs.

ZnS:Eu nanoparticles also have the ability to produce reactive oxygen species that can be used to treat cancers. Eu doped zinc sulfide quantum dots (QDs) were prepared by the chemical Co-precipitation method. X-ray diffraction analysis (XRD), scanning electron microscopy (SEM) and infrared Fourier transform (FT-IR) analysis were used to characterize the quantum dots. The photoluminescence spectrum (PL) of ZnS:Eu QD in excitation wavelength of 280 nm shows two emission peaks at 384 and 715 nm. In order to use these QDs as photosensitizer in photodynamic therapy, anthracene and methylene blue chemical detectors were used for detection of singlet oxygen and hydroxyl radical, respectively. The significant point for these quantum dots is that, in addition to production of hydroxyl radical, they also have the ability to produce singlet oxygen with UV-C radiation. The antimicrobial effect of ZnS:Eu QDs was also investigated using a disc diffusion method on 11 microbial strains. Zinc sulfide nanoparticles with Europium impurities can have good medical application due to their good antibacterial activity and ability to produce reactive oxygen species.

A new creatinine molecular imprinted polymer on the surface of goethite nanorods (CMIPG) was synthesized using the core-shell structure for the absorption and identification of creatinine. Nano goethite particles (NG) that had been modified with fumaric acid were employed as a core, and a polymerization procedure was carried out in the methacrylic acid (MAA) presence as a functional monomer and creatinine as a template on the surface of the modified goethite nanorods (MGN). Characterization of the CMIPG by energy dispersive spectroscopy-coupled scanning electron microscopy (SEM-EDS), field emission scanning electron microscopy (FESEM), Fourier transform infrared (FT-IR), and thermal gravimetric analysis (TGA) showed that the polymerization was successful. The effect of different factors such as pH, contact time, the amount of the adsorbent, imprinting efficiency, and primary creatinine concentration on creatinine adsorption capacity of CMIPG were evaluated and the results showed that recognition sites were created on the nanoparticles’ surface through the polymerization process. The ability of CMIPG for selective identification was studied by the binary solution of creatinine and its analogous such as creatine, L-tyrosine, and N-hydroxysuccinimide (NHS) revealing its ability to selectively absorb creatinine. Moreover, the CMIPG's release and reusability, isotherm, and kinetic models were examined.

Because of its unique qualities, concrete is the second most commonly utilized building material after water. However, there are significant downsides to the Portland cement manufacturing process, producing one ton of carbon dioxide per every ton of Portland cement. As a result, the usage of a Portland cement substitute appears to be required. On the other hand, the "waste-free" idea and the manufacturing of new materials with an environmental impact will be less important in future cities than the aims of sustainable development. To further develop environmentally friendly materials, it is vital to understand the environmental stimuli of novel materials as well as to assess the environmental effects of standard building materials. Geopolymers are ceramic-like materials with three-dimensional poly-compact structures that are made by chemically activating aluminum and silica-containing solids at low temperatures. Industrial wastes or by-products like coal combustion ash, smelting iron furnace slag, construction debris, or agricultural waste like rice husk ash can be utilized to make geopolymer concrete and construction. The present article reviews the studies on the use of geopolymer technology in sustainable materials to develop urban sustainability and reduce the emission of environmental pollutants with a life cycle assessment approach. Findings and results of studies show that geopolymer concretes have higher mechanical, chemical, and energy consumption properties than conventional concrete and offer significant environmental benefits.

Decellularization is the process of eliminating the cellular compartment of living tissues chemically or physically, resulting in an acellular extracellular matrix (ECM) scaffold that can be employed for a variety of reasons. Decellularized matrices are useful for tissue engineering applications because they preserve the tissue-specific mechanical, biochemical, and structural microenvironments while facilitating cellular engraftment and activities in the matrix. A variety of tissues have been decellularized by a variety of mechanical, chemical, and enzyme-based techniques and used to create bio scaffolds for diverse cell types such as primary cells, progenitor cells, and stem cells. Various applications and approaches are used in ocular tissue engineering and regeneration. Repairing the damaged structure in the corneal epithelium or the retinal ganglion cells is one of them. Scaffolds of biocompatible, biodegradable, natural, or synthetic polymers may be used in such applications. Stem cells can also be used to replicate vital cells in order to maintain vision function. Decellularized matrices can be used to create scaffolds for ocular tissue engineering, artificial arteries, cell culture matrices, and transplantation carriers, among other things. To gain a better understanding of regenerative medicine, we'll look at different types of decellularized tissue matrices and how they've been used to create artificial organs and regenerate injured tissues.

Hydrogels made from a variety of materials may be used as a novel technology in regenerative medicine in the biomedical field. Hydrogels may be made using both chemical and physical processes, depending on the source material. Size, elastic modulus, swelling, and degradation rate are only a few of the many physical parameters that may be used to define hydrogels in experiments. Hydrogels made from natural polymers have been the focus of our review. Due to their remarkable biocompatibility and nontoxicity, simple gelation, and functionalization, hydrogels derived from natural polymers have received extensive attention in recent decades. As a result, natural polymer hydrogels are considered excellent biomaterials that have great potential in the biomedical field. Because carriers play such a large role in determining how far and how fast drugs reach their intended recipients, the need for intelligent drug delivery systems (DDSs) is on the rise. An outstanding goal of this study is to examine the impact that various crosslinking process parameters have on the drug delivery mechanism.

Nowadays, providing powerful and green energy sources is one of the main challenges for a cleaner environment. Rechargeable lithium-ion batteries (LIBs), as effective energy storage devices, have gained lots of attention because of their relatively low self-discharge rate, high energy density, and rapid response. Since the efficiency of LIBs is significantly dependent on electrode materials; attention has been paid to the design of various electrodes.  carbon materials with their special structural, electrical, and mechanical properties are considered promising anode materials in LIBs. However, more research is still needed to identify suitable carbonaceous materials to improve the properties of anodes. In this regard, transition metals and silicon as high-capacity anodes can combine with carbon to develop LIBs. In this review, the employed carbonaceous materials and their composites as well as their outlook for LIB anodes have been investigated.