Mechanical Disintegration Research Articles

Cellulose nanofiber aerogels modified with titanium dioxide nanoparticles as high-performance nanofiltration materials

Air pollution is a major environmental and public health issue. Each year, large amounts of particulate matter (PM) and other harmful pollutants are released into the atmosphere. Conventional polymer nanofiber filters lack the functionality to capture ultrafine PM. As a sustainable alternative, this work developed titanium dioxide (TiO2) nanoparticle surface-modified cellulose nanofiber (CNF) aerogels for PM2.5 filtration. CNFs were extracted via mechanical disintegration to diameters below 100 nm. The nanofibers were functionalized with 1.0–2.5 wt% TiO2 nanoparticles using citric acid cross-linking. Cylindrical aerogels were fabricated by freezing and lyophilizing aqueous suspensions. Structural, morphological, thermal, and mechanical properties were characterized. TiO2 modification increased density (11.8–19.7 mg/cm3), specific surface area (287–370 m2/g), and Young's modulus (33.5–125.5 kPa) but decreased porosity (99.6 %–97.7 %), pore size (20.2–15.6 nm) and thermal stability compared to unmodified cellulose aerogels. At 2.5 wt% loading, the optimized aerogels achieved 100 % absorption of 0.1–5 μm particulates owing to reduced pore size. Despite enhanced filtration capabilities, the modified CNF aerogels retained inherent biodegradability, degrading over 70 % within one month of soil burial. This pioneering research establishes TiO2 functionalized CNF aerogels as promising sustainable alternatives to traditional petroleum-based air filters, representing an innovative approach to creating next-generation nanofiltration materials capable of effectively capturing fine and ultrafine particulate matter pollutants.

Characterization of acute and subacute immune response to boiling histotripsy ablation of pancreatic adenocarcinoma

Boiling histotripsy (BH) is a cavitation-based pulsed focused ultrasound method of mechanical tissue disintegration. When applied to tumor ablation, BH was shown in a number of preclinical studies to stimulate antitumor immune responses, with the extent and dynamics depending on the tumor microenvironment. In this work, we assessed the response of pancreatic ductal adenocarcinoma (PDAC)—an immunologically “cold” tumor—to BH ablation. C57BL/6J mice (n = 6 per group) were bilaterally subcutaneously grafted with KPC-derived mT4 cell line in the hind limbs. When one of the two tumors reached 8 mm, 80% of its volume was ablated with BH (1.5 MHz, 3 ms pulses, 1% duty cycle, 450 W power, 15 pulses/point). The tumors, inguinal lymph nodes and spleens were harvested at 1-, 3-, and 6-day time points and processed for immune phenotyping through flow cytometry, histology, and immunohistochemistry. At earlier time points, the response within the tumor was dominated by neutrophils, and by day 6—by inflammatory monocytes both in treated and contralateral sides versus sham. Transient increases in B cells, neutrophils, NK, NKT cells, and monocytes were observed in the ipsilateral lymph nodes and in spleens on day 3, and mostly subsided by day 6. These data will inform further studies in optimization of combination therapies for PDAC. [Work supported by Focused Ultrasound Foundation.]

Oral Dissolving Films: A Review

Oral dissolving films (ODFs) are thin, flexible, and fast-dissolving sheets that can deliver active substances to the oral cavity. They offer several advantages over conventional oral dosage forms, such as ease of swallowing, precise dosing, improved patient compliance, and rapid onset of action. ODFs can be used for various therapeutic applications, such as anti-ulcer, anti-asthmatic, antihistamine, and analgesic drugs. This review article presents a comprehensive analysis of recent advancements in ODF formulation, manufacturing techniques, and their diverse applications in pharmaceutical, nutraceutical, and biomedical fields. The formulation of ODFs involves the selection of suitable polymers, plasticizers, surfactants, flavours, and sweeteners. The polymers are the main component that determines the mechanical properties, disintegration time, and drug release profile of the films. The plasticizers are added to improve the flexibility and elasticity of the films. The surfactants are used to enhance the solubility and permeability of the drugs. The flavours and sweeteners are used to mask the unpleasant taste of the drugs and improve the palatability of the films. The production methods of ODFs include solvent casting, hot melt extrusion, and roll casting. These methods differ in terms of the equipment, process parameters, and film quality. Each technique's advantages, limitations, and potential for scalability are outlined, providing insight into the critical factors influencing ODF development. In summary, this review article provides a comprehensive overview of the recent progress in ODF technology, encompassing formulation optimization, manufacturing advancements, and innovative applications. As the field of oral dissolving films continues to evolve, this article offers valuable insights for researchers, clinicians, and pharmaceutical industry stakeholders seeking to harness the full potential of this versatile drug delivery platform. Keywords: Oral dissolving films, Plasticizer, Solvent casting method, Hot melt extrusion, Roll casting

Towards simultaneous determination of tablet porosity and height by terahertz time-domain reflection spectroscopy

The quality control of pharmaceutical tablets is still based on testing small sample numbers using at- and off-line testing methods. Traditional in-process controls, such as tablet mass, height, mechanical strength, and disintegration time are time- and resource-consuming and poorly suited to support an effective transition towards continuous manufacturing. Another suitable parameter to monitor during production would be tablet porosity. Porosity can be linked to mechanical strength and disintegration but typically requires knowledge of tablet dimensions and mass. Tablet porosity measurements based on terahertz time-domain spectroscopy (THz-TDS) offer a fast and non-destructive approach to in-process control testing for physical tablet properties. This study presents THz-TDS reflection measurements as an alternative to the previously reported transmission setup. It is shown that the proposed method can determine porosity based on the reflected amplitude from the tablet surface, but also allows for precise determination of tablet height in the same measurement. The tablet mass can be estimated by combining the height and porosity measurements. This opens up for the opportunity to determine the tablet's mechanical strength by using the possible correlation to the determined porosity.

Calcium peroxide induced mechanical disintegration in acidic environment for efficient biogas and biopolymer generation from paper mill sludge

The proposed research envisioned to improve the accessibility of organics and hydrolysis of paper mill waste activated sludge for polyhydroxybutyrate production and anaerobic digestion. In order to fill this research gap an exploration has been made by adding lower dosage of calcium peroxide at acidic pH for the removal of exopolymeric substances thereby improving the disintegration efficacy. The results indicate that the calcium peroxide dosage of 0.06 g/g SS at pH 5 was optimum for floc fragmentation. The influence of floc fragmented sludge on disintegration by disperser shows the solubilization and solid decrement of 18.8% and 12.4% at the specific energy input of 4729.24 kJ/kg total solid. The impact of pretreated supernatant on polyhydroxybutyrate accumulation shows the maximum polyhydroxybutyrate content of 85.03 % while utilizing 60% (v/v) of pretreated sludge supernatant as a carbon source at 42 h. Subsequently, the settled sludge was directed towards an anaerobic biodegradability assay and found about 167 mL/g of chemical oxygen demand of biogas generation, which is higher than the crude sample (52 mL/g of chemical oxygen demand). The higher solubilization in pretreated sample reveals the easier accessibility of substrate by the microorganisms, thereby enhances bioenergy and valued product generation.

Sodium lauryl sulfate as lubricant in tablets formulations: Is it worth?

Lubricants are excipients used in tablet formulations to reduce friction and adhesion forces within the die or on the punches surface during the manufacturing process. Despite these excipients are always required for the tablets production, their amount must be carefully evaluated since lubricants can negatively impact on mechanical strength, disintegration and dissolution behavior of solid dosage forms. Alternative compounds have been suggested to overcome the issues of conventional lubricants and sodium lauryl sulfate (SDS) is one of the most promising one. Despite SDS has been object of several investigations, a definitive conclusion on its effectiveness cannot still be drawn. Particularly, its efficacy on tablets disaggregation and API dissolution is still unclear. Here, the effect of SDS on all the relevant features of tablets and tableting process has been evaluated on immediate release hydrophobic tablets formulations in comparison with conventional lubricants. The results of this investigation are quite outspoken: SDS has a low lubricant power while it determines only a limited improvement on tablets hardness. It greatly improves the tablets wettability but only on model formulations, the presence of superdisintegrants resets its effectiveness and any possible effect on tablets disaggregation. None of the tested formulations showed improvement on the API dissolution rate.

Cellulose Nanocrystal Preparation via Rapid Hydrolysis of Wood Cellulose Fibers Using Recyclable Molten Ferric Chloride Hexahydrate

Cellulose nanocrystals (CNCs) are clean and sustainable materials that have drawn significant attention in academia and industry because of their unique physicochemical properties. However, realizing economical and environmentally friendly production of CNCs remains a challenge. In this study, we proposed an innovative strategy to fabricate CNCs, which involves the acid hydrolysis pretreatment of wood cellulose fibers using innocuous and recyclable ferric chloride hexahydrate (FeCl3·6H2O). During the molten FeCl3·6H2O treatment, the degree of polymerization (DP) of the cellulose fibers sharply decreased, along with the transformation of cellulose I to cellulose II crystallites. Molten FeCl3·6H2O quickly hydrolyzed cellulose fibers within 5 min at 80 °C, inducing a rapid decrease in the DP from 922 to 196, and the water-insoluble solid (WIS) retention reached 80.1%. CNCs were successfully produced from the mechanical disintegration of the WIS with a low energy input. Hence, the yield of CNCs is consistent with that of the WIS. Interestingly, the CNCs exhibited typical cellulose II crystallites, which were significantly different from those of the cellulose feedstock (cellulose I). Detailed characterization revealed that the CNCs had tunable number-averaged heights of 10.4–26.9 nm and high thermal stability (a maximal weight loss temperature of 327 °C). Most notably, FeCl3·6H2O was easily recycled from the hydrolysate after hydrolysis, with a high recovery of 94.0–94.5 wt %, using simple concentration and crystallization technologies. Thus, this study proposes a novel production technology for CNCs that is both economical and eco-friendly, providing new ideas for clean and large-scale production of CNCs.

Mechanical properties and disintegration behavior of EICP-reinforced sea sand subjected to drying-wetting cycles

Enzyme-induced carbonate precipitation (EICP) has emerged promising in various geotechnical applications, and has been presented as an alternative to the traditional cementitious materials-based ground improvement method. However, the study on mechanical properties and disintegration behavior of EICP-reinforced sea sand subjected to drying-wetting cycles are limited. This study investigated the mechanical properties and disintegration behavior of EICP-reinforced sea sand against the impact of drying-wetting (D-W) cycles. The uniaxial compressive strength (UCS) tests were performed to discuss the effect of drying-wetting cycles on the mechanical behavior of EICP-treated sea sand. The disintegration tests were conducted on EICP-treated sea sand to investigate the disintegration resistance of bio-cemented samples with various cementation levels. The microstructures of samples before and after disintegration were examined to disclose the disintegration mechanisms of EICP-reinforced sea sand. D-W cycles significantly affect the mechanical properties of EICP-reinforced sea sand, with UCS decreasing by 63.7% after undergoing 15 D-W cycles. The disintegration resistance index of specimens with a lower cementation level decreases significantly under the effect of D-W treatment. The higher disintegration resistance of specimens with higher cementation can be attributed to more crystals with better crystallinity formed in the contact point between sand particles within specimen. The crystals formed by soybean husk urease are mainly calcite and the crystallinity of spherical calcites would gradually change into larger rhombic calcite with further bio-grouting. The crystal with poor crystallinity is susceptible to the effect of D-W treatment, resulting in the obvious disintegration of EICP-reinforced sea sand. Overall, this study is expected to provide useful guidance on the long-term stability and drying-wetting disintegration mechanisms of EICP-reinforced sea sand.

Impact of Surface Roughness on the Impingement of Urea–Water Solution Droplets

The understanding of impingement processes is crucial for optimizing automotive selective catalytic reduction (SCR) systems. An accurate description of this behavior helps design exhaust systems and increases the validity of modeling approaches. A component test bench was set up, featuring a droplet chain generator for producing droplet sizes typically found in the urea–water solution sprays of SCR systems. A heatable impingement plate with an interchangeable surface enabled investigation of the influence of surface roughness. Data were acquired using a high-speed camera and image postprocessing. The droplet–wall interaction could be described using different regimes. An approach to characterizing impingement behavior based on weighted-regime superposition enabled gradual transitions between regimes, instead of step-like changes. It was observed that the surface roughness increased the droplet–solid contact area and generated thermal-induced secondary droplets at lower temperatures. A region of enhanced mechanical disintegration of the droplet was found, caused by peaks of the surface shearing off parts of the droplet. The probability of a droplet rebounding from the wall was reduced on a rough surface, due to the interference of the surface spikes with the droplet’s spreading and contracting motion. Additionally, the influence of surface topography was investigated using a shot-peened surface. Caused by this surface’s reduced root mean square slope, the aforementioned enhancement of mechanical disintegration was not observed.

Pilot ex vivo study on non-thermal ablation of human prostate adenocarcinoma tissue using boiling histotripsy

Focused ultrasound technologies are of growing interest for noninvasive ablation of localized prostate cancer (PCa). Here we present the results of the first case study evaluating the feasibility of non-thermal mechanical ablation of human prostate adenocarcinoma tissue using the boiling histotripsy (BH) method on ex vivo tissue. High intensity focused ultrasound field was generated using a 1.5-MHz custom-made transducer with nominal F#=0.75. A sonication protocol of 734 W acoustic power, 10-ms long BH-pulses, 30 pulses per focal spot, 1 % duty cycle, and 1 mm distance between single foci was tested in an ex vivo human prostate tissue sample containing PCa. The protocol used here has been successfully applied in the previous BH studies for mechanical disintegration of ex vivo prostatic human tissue with benign hyperplasia. BH treatment was monitored using B-mode ultrasound. Post-treatment histologic analysis demonstrated BH produced liquefaction of the targeted tissue volume. BH treated benign prostate parenchyma and PCa had similar tissue fractionation into subcellular fragments. The results of the study demonstrated that PCa tumor tissue can be mechanically ablated using the BH method. Further studies will aim on optimizing protocol parameters to accelerate treatment while maintaining complete destruction of the targeted tissue volume into subcellular debris.

Swelling and flow of expanding clays as a cause for non‐tectonic deformations in a glacial–interglacial environment: Holy Cross Mountains, Poland

AbstractNot all deformational structures are tectonic in nature. Those that do not form under the influence of endogenic causes, but are the result of, for example, gravity, compaction or diapiric extrusion, are referred to as non‐tectonic phenomena. An example of such deformation is the steep and overturned dips of Callovian and Oxfordian layers in the gently folded Mesozoic cover of the Holy Cross Mountains. Their steepening was a result of processes taking place in the underlying ductile formations of Keuper–Rhaetian (Upper Triassic) and Bathonian, slightly enhanced by glaciotectonics. The latter are dominated by claystones, with a minor share of mudstones and sandstones. Their plasticity was due to a significant share of mixed‐layer minerals of smectite‐illite type, which under conditions of high water could swell. Low‐density water‐saturated clays were extruded from under the edge of a limestone slab leading to its deformation. The diapiric flow of the clay‐mass was stimulated by low temperature, high water saturation of rocks and mechanical disintegration associated with freeze–thaw processes during the Pleistocene.

Long-term impact of pulses and organic amendments inclusion in cropping system on soil physical and chemical properties

Mono-cropping of maize–wheat, mechanical disintegration of soils, and continuous chemical fertilization have deteriorated soil health in the Indo-Gangetic Plains. We studied the long-term impact of pulse-based cropping systems with integrated nutrient management on soil physical and chemical properties and yield sustainability. We evaluated four different cropping systems: (1) maize–wheat (M–W), (2) maize–wheat–mungbean (M–W–Mb), (3) maize–wheat–maize–chickpea (M–W–M–C), (4) pigeonpea–wheat (P–W) each with three degrees of soil fertilization techniques: (1) unfertilized control (CT), (2) inorganic fertilization (RDF), and (3) integrated nutrient management (INM). The field experiment was undertaken in a split-plot design with three replications each year with a fixed layout. P–W and M–W–Mb systems enhanced soil properties such as volume expansion by 9–25% and porosity by 7–9% (p < 0.05) more than M–W, respectively. P–W and M–W–Mb increased soil organic carbon by 25–42% and 12–50% over M–W (RDF). P–W system enhanced water holding capacity and gravimetric moisture content by 10 and 11% (p < 0.05) than M–W. Pulse-based systems (P–W and M–W–Mb) had higher available nitrogen (8–11%), phosphorus (42–73%), and potassium (8–12%) over M–W (p < 0.05). M–W–Mb increased 26% maize yield and 21% wheat yield over M–W (p < 0.05) at the thirteenth crop cycle. P–W system had a higher sustainable yield index (p < 0.05) of wheat over the M–W. Thus, pulse inclusion in the cropping system in combination with INM can enhance physical and chemical properties vis-à-vis sustainable yield index over the cereal-cereal system.

The impact of apple destructuring and thermal treatment on bioactive compounds: the fate of dietary fibre and polyphenols in puree and homogenate

SummaryThe present study aimed at understanding the response of dietary fibres and phenolic compounds to apple matrix disintegration and thermal treatment. Apple was processed by mimicking industrial operations of blanching, destructuring by high‐speed homogenisation (HSH) or high‐pressure homogenisation (HPH), and pasteurisation. A viscous puree (0.73 Pa × s), made of juice embedding intact cells and large cell clusters, was obtained by HSH. Conversely, HPH completely disrupted apple tissue leading to a fluid homogenate (0.27 Pa × s) in which the fibrous matrix was suspended. Despite these differences, apple puree and homogenate presented similar content of total and soluble dietary fibre, with no significant differences in the chemical structure of apple pectin, as demonstrated by FT‐IR and NMR analyses. Apple puree and homogenate retained more than 80% of the phenolic content originally present in apple pulp (about 2125 mg/gdw) without detriment to radical scavenging activity. This minor phenolic depletion, regardless of the different extent of mechanical disintegration, was mainly due to the decrease of thermolabile flavanols upon application of analogous heat treatments.

Figure‐of‐Merit Compatibility of Solid Oxide Fuel Cells

Solid oxide fuel cell (SOFC) is one of the most efficient energy converters which can produce electricity from reactions of gaseous chemicals. However, a high operating temperature (T o) of 800–1200 °C is required to achieve the highest peak performance. Such high T o triggers miscellaneous problems, that is, mechanical disintegration with further degradation of its electrical performance for a long‐term application. Despite accomplishing various approaches for the improvement of SOFC performance, the standard level to determine SOFC performance has never been achieved. To date, a quantitative analysis is only pinpointing the power output density (P out). The SOFC cannot be simply determined by a mere P since other parameters that is chemical stability between SOFC components, mismatch of thermal expansion coefficient, and area‐specific resistance also contribute to the mechanical durability and electrochemical stability of the SOFC. Hence, herein, a novel idea is proposed to characterize the overall performance of SOFC through the figure‐of‐merit compatibility (χ cp) of SOFC cells. The χ cp can reflect a level of SOFC performance, thus it can be utilized for future improvements.

Pigment Production of Chlamydomonas Strains in Response to Norflurazon and ZnO Nanoparticles

Numerous species of microalgae have been utilized for pigment production. More and more species are gaining popularity due to their ability to accumulate pigments with varying chemical compositions and the fact that some have distinctive byproducts that can be co-produced. Despite the fact that many of the species have unique by-products and traits, they are not being used economically due to high production costs. Utilizing agricultural and industrial wastewater for algae cultivation is one way to lower manufacturing costs. Herbicide-contaminated wastewater can result from agricultural contamination. Norflurazon is a popular pesticide frequently used for weed control. The presence of norflurazon in water renders that water unusable and requires proper treatment. Nanoparticles of ZnO (ZnO NPs), on the other hand, are utilized in a variety of industrial productions of numerous household goods. Water contaminated with ZnO NPs can present potential risks to human health and the environment. In this study, two field isolates of the green microalga Chlamydomonas reinhardtii, a widely used model organism, were examined for their reaction to these two compounds in order to assess the responses of different natural strains to environmental stresses. Norflurazon at 10 µM had a higher inhibitory effect on growth and pigment production than ZnO NPs at 200 mg L−1. Although both norflurazon and ZnO NPs inhibit cell growth and pigmentation, they do so through distinct processes. Norflurazon induces oxidative stress in cells, resulting in photosystem damage. ZnO nanoparticles, on the other hand, did not cause photosystem damage but rather mechanical cell damage and disintegration. In addition, the physiological responses of the two Chlamydomonas strains were distinct, supporting the utilization of natural algal strains for specific types of environmental pollutants.

How Cooking Time Affects In Vitro Starch and Protein Digestibility of Whole Cooked Lentil Seeds versus Isolated Cotyledon Cells.

Lentils are sustainable sources of bioencapsulated macronutrients, meaning physical barriers hinder the permeation of digestive enzymes into cotyledon cells, slowing down macronutrient digestion. While lentils are typically consumed as cooked seeds, insights into the effect of cooking time on microstructural and related digestive properties are lacking. Therefore, the effect of cooking time (15, 30, or 60 min) on in vitro amylolysis and proteolysis kinetics of lentil seeds (CL) and an important microstructural fraction, i.e., cotyledon cells isolated thereof (ICC), were studied. For ICC, cooking time had no significant effect on amylolysis kinetics, while small but significant differences in proteolysis were observed (p < 0.05). In contrast, cooking time importantly affected the microstructure obtained upon the mechanical disintegration of whole lentils, resulting in significantly different digestion kinetics. Upon long cooking times (60 min), digestion kinetics approached those of ICC since mechanical disintegration yielded a high fraction of individual cotyledon cells (67 g/100 g dry matter). However, cooked lentils with a short cooking time (15 min) showed significantly slower amylolysis with a lower final extent (~30%), due to the presence of more cell clusters upon disintegration. In conclusion, cooking time can be used to obtain distinct microstructures and digestive functionalities with perspectives for household and industrial preparation.

Amelioration of Biogas Production from Waste-Activated Sludge through Surfactant-Coupled Mechanical Disintegration

The current study intended to improve the disintegration potential of paper mill sludge through alkyl polyglycoside-coupled disperser disintegration. The sludge biomass was fed to the disperser disintegration and a maximum solubilization of 6% was attained at the specific energy input of 4729.24 kJ/kg TS. Solubilization was further enhanced by coupling the optimum disperser condition with varying dosage of alkyl polyglycoside. The maximum solubilization of 11% and suspended solid (SS) reduction of 8.42% were achieved at the disperser rpm, time, and surfactant dosage of 12,000, 30 min, and 12 μL. The alkyl polyglycoside-coupled disperser disintegration showed a higher biogas production of 125.1 mL/gCOD, compared to the disperser-alone disintegration (70.1 mL/gCOD) and control (36.1 mL/gCOD).

Processing Polymer Blends of Mater-Bi® and Poly-L-(Lactic Acid) for Blown Film Application with Enhanced Mechanical Strength.

Mater-Bi® is one of the most commercialized starch-based blends used in biodegradable flexible packaging. However, the high ductility and low stiffness of Mater-Bi® might limit its application and developing a solution to tailor the stiffness and mechanical strength is highly desirable. In the present work, blends based on Mater-Bi® and poly-L-(lactic acid) (PLLA) at a different ratio from 70/30 to 50/50 wt% were prepared via melt-extrusion and the effect of the PLLA content and Joncryl ADR® as a reactive compatibilizing agent, on the mechanical properties, melts rheology, morphology and disintegration aptitude were investigated. The inclusion of PLLA in Mater-Bi® has a marked beneficial effect on the tensile strength and stiffness of the blend while maintaining acceptable ductility. The addition of the reactive compatibilizing agent contributed to improving the strength and elongation at the break of the blend. The melt rheology of the blend was also affected by the ratio of the two components, mostly when the Joncryl ADR® was present. The disintegration by biodegradation of the blend was preserved in the presence of PLLA, and it takes less than 30 days for the films to completely decompose and disintegrate under controlled composting conditions. Interestingly, a thin film from Mater-Bi®/PLLA 60/40 was successfully prepared by blown film extrusion, demonstrating a good balance between stretchability (elongation at break exceeding 100%) and stiffness (1.8 GPa). This work opened to broadening the use of starch-based biodegradable plastic toward more demanding applications such as mulching films.

Comparing methods for protozoa removal in activated sludge

One of the key technological parameters for highly efficient wastewater treatment methods is bacterial mortality. Protozoa are known for feeding on free floating bacteria, that initiate floc formation and participate in putrefaction process. Reliable protozoa removal methods are still unavailable which have negative impact on the development of the current knowledge in this field. The aim of this study was to find the most effective method which removes most of protozoa present in the activated sludge without affecting the overall treatment efficiency. Seven possible methods of removing protozoa were tested by analysing several technological parameters. The evaluation of the presented methods was based on the efficiency of protozoa removal, as well as on the effects of the removal methods on autotrophic, heterotrophic and endogenous oxygen uptake. Mechanical disintegration proved to be the most effective and reliable method. It allowed for the complete removal of protozoa without the inhibition or inactivation of bacteria. The comprehensive and complete data obtained from the conducted research will be used to improve existing wastewater treatment processes with regards to both the technological point of view and mathematical modelling.

Evaluation to possibility of cellulose fibers isolated from kapok randu (Ceiba Pentandra) as a precursor growth of carbon micro structures with the assist of metal catalysts

ObjectiveAs a hydrocarbon material, cellulose could be used as precursor in synthesizing carbon micro-structure (CMTs), and this study aims to investigate the potential use of cellulosic material from kapok randu as a precursor in synthesizing carbon-based structures. MethodsThe isolation of cellulose was carried out via alkaline treatment, followed by mechanical disintegration. Meanwhile, the growth of CMTs was performed via heating treatment for 12 h with various catalysts (i.e., Fe, Ni, and Cu). Chemical characteristics were confirmed by FTIR, XRD spectra, while TEM, SEM and Raman spectra were performed to determine the growth of CMTs. ResultsThe thermal characteristic suggested that the decomposition was initiated at 300 °C. The FTIR results confirmed the presence of functional groups in accordance to cellulose fiber, such as –OH (3418 cm−1), CH aliphatic group (2900 cm−1), OH (1635 cm−1), and CH (1334 cm−1). Whilst, the FTIR pattern also confirmed the presence of CC stretching at 1600 cm−1, –CH in between 2800 and 3000 cm−1, indicating the activated carbon. Raman shift indicated the growth on G-band in the interval of 1500–1700 cm−1, suggesting the presence of CC structures. Based on the morphological characteristics, the growth of CMTs were successfully obtained with different diameters and lengths due to the different catalysts used. The iron (Fe) catalysts produced CMTs with a diameter about 200 nm and average length of 2–3 µm, whereas the Ni catalysts formed tubes with around 150 nm of length and 50 nm of diameter. Meanwhile, the Cu catalysts formed amorphous particles with diameter below 10 nm. ConclusionFrom these results, the evaluation of cellulose isolated from kapok randu as a precursor in the growth of carbon micro-tube with distinguished characteristics was demonstrated.