16 research outputs found
Sugarcane Bagasse and Cellulose Polymer Composites
Waste recycling has been the main topic of various scientific researches due to environmental management. Renewable agricultural sources such as pineapple leaf, sisal, jute, piassava, coir, and sugarcane bagasse are among agro waste, normally known as biomass, which is recently used for reinforcing polymeric materials. Sugarcane bagasse fiber residues has been extensively investigated and employed as a source of reinforcement of polymers. The major residue is normally burnt for energy supply in the sugar and alcohol industries and as a result, tons of ash is created. The ash contained inorganic components which are valuable for reinforcement in polymeric materials. This chapter reports on the use of sugarcane bagasse, sugarcane bagasse ash (SBA) and its cellulose as reinforcing fillers for polymers
Effect of Sugarcane Bagasse, Softwood, and Cellulose on the Mechanical, Thermal, and Morphological Properties of PP/PE Blend
The usage of cellulosic fibers as fillers for thermoplastics has generated great interest due to their numerous advantages and benefits compared to conventional fibers. This article examines a comparative study on the mechanical, thermal, and morphological properties of polypropylene/polyethylene (PP/PE)/cellulose (sugarcane bagasse (SCB) and softwood (SW)) blend composites prepared through melt compounding. The morphology of the obtained PP/PE/SCB and PP/PE/SW blend composites was investigated using scanning electron microscopy (SEM). The X-ray diffraction (XRD) analysis showed reduced crystallinity of the PP/PE blend after fiber interaction. Thermal results showed that the PP/PE/SW blend was more thermally stable compared to the PP/PE/SCB blend. Additionally, the onset temperature of main degradation decreased with th e incorporation of extracted celluloses. Differential scanning calorimetry (DSC) analysis revealed that the introduction of SCB or SW raw fiber and extracted celluloses did not significantly change the melting and crystallization behavior of the PP/PE blend. Dynamic mechanical analysis (DMA) revealed that the storage modulus of the PP/PE/SCB raw and PP/PE/SW raw materials were lower than their corresponding cellulose blend composites across the temperature range studied
Thermal Degradation Kinetics of Sugarcane Bagasse and Soft Wood Cellulose
The properties of untreated sugar cane bagasse (SCB) and soft wood (SW) and their respective celluloses were investigated. The celluloses indicated improved crystallinity index values and decreased concentration of lignin and hemicellulose compared to their untreated counterparts. Three degradation models, Kissinger-Akahira-Sunose (KAS), Flynn-Wall-Ozawa (OFW), and Kissinger (KGR) methods were employed to determine apparent activation energy values. Generally, the thermal degradation processes of both sugarcane bagasse and soft wood included dehydration, degradation of hemicellulose and cellulose, whereas the lignin degraded from the degradation temperature of hemicellulose to the end of the cellulose. The apparent activation energy values obtained from the OFW and KAS models vary with the degree of conversion, and showed similar trends. The activation energies obtained by KGR were relatively lower than those obtained from the KAS and OFW methods
Effect of Acetylation on the Morphology and Thermal Properties of Maize Stalk Cellulose Nanocrystals: A Comparative Study of Green-Extracted CNC vs. Acid Hydrolysed Followed by Acetylation
This study highlights the advantages of employing acetylation to enhance the morphology and thermal properties of cellulose nanocrystals (CNCs) derived from maize stalks. Utilizing a green synthesis approach for CNC extraction, this research presents a novel comparison between green extracted CNCs, and their acid hydrolysed, followed by their acetylated counterparts (ACCNCs). This comparison reveals significant improvements in the properties of acetylated CNCs over those produced through conventional acid hydrolysis. The study employs advanced characterization techniques, including Fourier Transform Infrared (FTIR) spectroscopy, X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Thermogravimetric Analysis (TGA), to analyze untreated maize stalk extracted cellulose, green extracted CNCs, and acetylated CNCs. FTIR spectroscopy identifies changes in functional groups, underscoring the efficacy of the extraction and modification processes. XRD analysis demonstrates a beneficial transformation from cellulose I to cellulose II allomorphs post-acetylation, with increased crystallinity index values indicating effective removal of amorphous regions. SEM imaging reveals the preservation of rod-like structures in CNCs, while acetylated CNCs exhibit advantageous morphological changes, such as reduced nanocrystal length and increased branching. TGA results show superior thermal stability in green extracted CNCs and favorable thermal degradation behavior in acetylated CNCs. Overall, this study underscores the potential of acetylation to develop sustainable nanomaterials with tailored properties, offering significant advancements for various applications. Emphasizing the advantages of the prepared ACCNCs and the green synthesis method over traditional acid hydrolysis extraction, this research paves the way for innovative applications in diverse fields
Dopants concentration on the properties of various host materials by sol-gel method: Critical review
Over the past years, the interest in doped phosphor materials has been extensively studied, due to their potential in applications such as light emitting diodes (LEDs), photonic circuits, sensors, and luminescent thin films. The most investigated phosphor materials by researchers include strontium aluminate, Zinc aluminate, magnesium aluminate, silica, and so forth. The incorporation of dopant ions in the host materials has shown a significant effect on the luminescence efficiency and the emission bands' position, which influences their kind of application. To achieve such luminescent materials, the sol-gel method has proved to be a competent method for the synthesis of doped phosphor materials due to its high purity, high homogeneity, and low-temperature processing. In this review, various sol-gel-prepared doped nanophosphor materials have been investigated. The effect of dopant concentration on the optical, morphological, and structural properties of nanophosphors were thoroughly discussed. Informative conclusions and up-to-date recommendations were drawn for future research and the possible establishment of new applications
A Review of the Impact of Zinc Oxide Nanostructure Morphology on Perovskite Solar Cell Performance
Zinc oxide (ZnO) has been widely studied over the last decade for its remarkable properties in optoelectronic and photovoltaic devices because of its high electron mobility and excitonic properties. It has probably the broadest range of nanostructured forms that are also easy and cheap to synthesize using a wide variety of methods. The volume of recent work on ZnO nanostructures and their devices can potentially overshadow significant developments in the field. Therefore, there is a need for a concise description of the most recent advances in the field. In this review, we focus on the effect of ZnO nanostructure morphologies on the performance of ZnO-based solar cells sensitized using methylammonium lead iodide perovskite. We present an exhaustive discussion of the synthesis routes for different morphologies of the ZnO nanostructure, ways of controlling the morphology, and the impact of morphology on the photoconversion efficiency of a given perovskite solar cell (PSC). We find that although the ZnO nanostructures are empirically similar, one-dimensional structures appear to offer the most promise to increasing photoconversion efficiency (PCE) by their proclivity to align and form vertically stacked layers. This is thought to favor electron hopping, charge mobility, and conductivity by allowing multiple charge conduction pathways and increasing the effective junction cross-sectional area. The combined effect is a net increase in PCE due to the reduced surface reflection, and improved light absorption
Developments on Perovskite Solar Cells (PSCs): A Critical Review
This review provides detailed information on perovskite solar cell device background and monitors stepwise scientific efforts applied to improve device performance with time. The work reviews previous studies and the latest developments in the perovskite crystal structure, electronic structure, device architecture, fabrication methods, and challenges. Advantages, such as easy bandgap tunability, low charge recombination rates, and low fabrication cost, are among the topics discussed. Some of the most important elements highlighted in this review are concerns regarding commercialization and prototyping. Perovskite solar cells are generally still lab-based devices suffering from drawbacks such as device intrinsic and extrinsic instabilities and rising environmental concerns due to the use of the toxic inorganic lead (Pb) element in the perovskite (ABX3) light-active material. Some interesting recommendations and possible future perspectives are well articulated
Encapsulation of Gold Nanorods with Porphyrins for the Potential Treatment of Cancer and Bacterial Diseases: A Critical Review
Cancer and bacterial diseases have been the most incidental diseases to date. According to the World Health Report 2018, at least every family is affected by cancer around the world. In 2012, 14.1 million people were affected by cancer, and that figure is bound to increase to 21.6 million in 2030. Medicine therefore sorts out ways of treatment using conventional methods which have been proven to have many side effects. Researchers developed photothermal and photodynamic methods to treat both cancer and bacterial diseases. These methods pose fewer effects on the biological systems but still no perfect method has been synthesized. The review serves to explore porphyrin and gold nanorods to be used in the treatment of cancer and bacterial diseases: porphyrins as photosensitizers and gold nanorods as delivery agents. In addition, the review delves into ways of incorporating photothermal and photodynamic therapy aimed at producing a less toxic, more efficacious, and specific compound for the treatment
A Thermic Effect on Degradation Kinetics of Sugar Cane Bagasse Polypropylene Composites
In this study, thermal degradation mechanisms and the kinetics of PP (Polypropylene) composites containing alkali and saline treated SC (Sugar cane bagasse) have been evaluated using a non-isothermal thermogravimetric analysis under consistent nitrogen atmosphere. The study indicates dynamics of kinetics that need to be considered should the composites be applied in high temperature applications. NaOH treated composites revealed a reduced fiber size compared to the other composites. The presence of SC generally reduced the functional group intensities of FTIR peaks, however some peaks re-emerged after the treatments. The composites indicated higher thermal stability and char content than the pristine polymer. In fact, NaOH treated composite is more thermally stable, while the saline is the least stable of the rest. Well known reliable degradation kinetics methods were employed in order to unpack thermal degradation behavior and possible metaphors. Flynn–Wall–Ozawa (FWO) and Kissinger–Akahira–Sunose (KAS) thermal degradation kinetic models are in agreement that the presence of both SC and those in the PP matrix that have been treated lead to increased activation energy values with the competing reactions in the degradation process. Nonetheless, the linear relation is not absolutely perfect and the competing reactions seem complex at lower temperatures as there are overlying inconsistencies in activation energies. Interestingly, bagasse indicated some effect on the mechanism that included the hindering of free radicals that emanated from the first cleavage of PP