Optimal Nanoparticle Research Articles

Ru/TiO2 Catalyzed High‐Yield Synthesis of Furanic Diols by 5‐Hydroxymethylfurfural Hydrogenation with Switchable Selectivity

Abstract5‐Hydroxymethylfurfural (HMF) is a versatile platform molecule that can be derived from biomass feedstocks and catalytically converted into various value‐added chemicals. In this work, selective hydrogenation of HMF is investigated to produce valuable furan‐based diols, namely 2,5‐bis‐hydroxymethylfuran (BHMF) and 2,5‐bis‐hydroxymethyltetrahydrofuran (BHMTHF), using TiO2 supported Ru catalysts. The catalyst performance was fine‐tuned to achieve over 98% yield to BHMF and BHMTHF under optimized reaction conditions with very good recyclability. We pointed out several key factors allowing to maximize the yield towards the respective diols. Features such as the Ru nanoparticle size, the strength of metal‐support interactions and the presence of residual chlorine were found to significantly influence the reaction. A characteristic volcano‐shaped relationship was obtained between the particle size and the catalytic activity giving the highest diol yield for an optimum Ru nanoparticle size of 1.6 nm. Further, metal‐support interactions were found to be responsible for providing optimum Ru‐TiOx interfacial surface sites and chlorine was affecting the electronic properties of Ru nanoparticles, potentially benefiting to the selective formation of BHMF. The reaction time was shown to control the hydrogenation of the furan ring and the selectivity of the reaction, that can be directed optimally towards BHMF or BHMTHF.

Optimising Nanoparticle Dispersion Time for Enhanced Thermomechanical Properties in DGEBA-Based Shape Memory Polymer Composites

Shape-memory polymers (SMPs) are smart materials that can change shape upon an external stimulus. This phenomenon is called the shape memory effect (SME), which is caused by entropy change due to rapid molecular motion in the polymer segments. Due to the inherently weak thermomechanical properties, use of SMPs is limited in many engineering applications. Therefore, SMPs are often reinforced with fibres and nanoparticles (NPs). NPs offered greater flexibility due to their superior physical, chemical, electrical, mechanical, and thermal properties. However, the homogeneous distribution of NPs is crucial for composition’s stability and enhancement of the base material’s properties. Among the different techniques used for dispersing NPs, ultrasonic irradiation has shown excellent emulsifying and crushing performance. The sonication process is essential for mitigating agglomerates; however, prolonged sonication time probably increases epoxy temperature, micro-bubbles, cavitation, breaking apart molecules and finally degrading the epoxy resin performances. This paper provides critical insight of nanoparticle dispersion into diglycidyl ether of bisphenol A epoxies (DGEBA). DGEBA epoxy resin was added to TiO2 NPs and sonicated for 60 min with 5 min intervals while the temperature of epoxy was maintained below 60oC by using a water cooling throughout the sonication process. The process parameters such as amplitude, mode, epoxy volume and the weight percentage of NPs were kept constant. After each sonication step, Fourier-transform infrared spectroscopy (FTIR) was performed using Thermo Scientific™ and analysed through OMNIC™ Professional quantitation software. In accordance with FTIR results, until 30 min of the sonication, DGEBA resin was not degraded. In order to confirm the performances and the reinforcing effect of NPs, thermo-mechanical and shape memory properties were compared with the neat specimen. The outcomes of this research have suggested quick guidance to find optimum NP dispersion time for DGEBA resins, which has been hardly studied before.

In vitro and in vivo evaluation of tedizolid nanoparticle incorporated buccal films for oromucosal infections

A novel tedizolid phosphate (TZP) nanoparticle (NP)-loaded buccal film formulation was developed for the treatment of buccal wounds infected with S. aureus. TZP-loaded chitosan NPs were produced and characterized to prepare this composite system. The optimum NP formulation was then loaded into mucoadhesive buccal films. The antibacterial effects of the obtained buccal films were evaluated by in vitro and in vivo studies. The optimum TZP-NP formulation (F8) had a particle size of 177.40 ± 2.97 nm and PDI and ZP values were 0.437 ± 0.002 and 33.9 ± 0.5, respectively. In antibacterial efficacy tests, the optimum NP containing buccal film formulation was used, which released approximately 90 % of TZP within 5 h. TZP-NP-loaded buccal films achieved a 3 log10 reduction in S. aureus within just 3 h. It was also administered to Wistar albino rats with S. aureus-infected buccal wounds. As a result of in vivo studies, a significant decrease in the number of S. aureus was detected in wound samples treated with TZP-NP-loaded buccal films. In addition, a complete inhibition of growth was observed on the fifth day of the film application. The current work suggested that the TZP-NP-loaded composite films could be promising candidates for effective and long-acting antibacterial treatment of buccal wounds.

Development of Mitoxantrone-Loaded Quercetin Nanoparticles for Breast Cancer Therapy with Potential for Synergism with Bioactive Natural Products

Nanoparticle (NP)-based drug delivery systems have caused a paradigm shift in cancer treatment by enabling drug targeting, sustaining drug release, and reducing systemic toxicity of chemotherapy. Here we developed a novel NP formulation for the anticancer drug mitoxantrone (MTZ) by loading it into an emerging nanomaterial derived from the plant polyphenol quercetin (QCT). QCT was partially oxidized to produce amphiphilic oxQCT which was co-assembled with poly(ethylene glycol) (PEG) and MTZ by nanoprecipitation to form MTZ NPs. The optimal NPs exhibited an average diameter of 128 nm, a polydispersity index of 0.22, and a drug loading efficiency of 76%. While only a small fraction of the loaded drug was released at physiologic pH, a significantly higher fraction was released at acidic pH. The anticancer activity of MTZ NPs was assessed in MCF-7 and MDA-MB-231 breast cancer cell lines, alone and in combination with the bioactive natural products curcumin (CUR) and thymoquinone (TQ). In cell viability assays, MTZ NPs were slightly less potent than free MTZ, most likely due to their sustained release properties, but their cytotoxicity was greatly enhanced in the presence of TQ (in MCF-7 cells) as well as CUR (in MDA-MB-231 cells). The results were corroborated by apoptosis assays such as mitochondrial membrane potential measurement, acridine orange/ethidium bromide staining, in addition to caspase activity assays. The assays revealed that the NPs’ proapoptotic effect was enhanced in the presence of CUR or TQ, depending on the cell line. Our work presents a promising nanocarrier platform for MTZ with the potential to enhance its bioactivity against breast cancer when combined with bioactive natural products.

Enhancement of Rheological Properties of Nano-Fe2O3-Modified Drilling Fluids

Summary In this study, we explore the potential of using nanoparticles (NPs) to enhance the properties of water-based drilling fluids (WBDFs). Specifically, we investigate the effects of nano-Fe2O3 on the rheological behavior of drilling fluid muds under high-temperature and high-pressure (HTHP) conditions to determine the optimal concentration of Fe2O3 NPs to maintain consistent rheology and improve drilling fluid systems. Results show that as temperature increases, the rheological properties of water-based muds (WBMs) decrease, leading to compromised structural integrity. To address this issue, nano-Fe2O3 is introduced into the system. We prepared and evaluated six WBM formulations with varying weight percentages of Fe2O3 NPs, and found that an optimal NP concentration of 2.5 g wt% resulted in a 13.8% reduction in American Petroleum Institute (API) filtrate volume and a 40% reduction in filter-cake thickness. Under conditions of 300°F temperature and 10,000 psi pressure, consistent reductions were observed in the rheological properties of plastic viscosity (PV), yield point (YP), and gel strength with the addition of Fe2O3 NPs. The YP-PV span was measured at 2.7, and the yield strength was determined to be 11 lb/100 ft2. Regarding fluid loss, Drilling Mudcake A containing 0.5 wt% NPs experienced a loss of 6 mL of fluid after 30 minutes, whereas Mudcake E containing 3 wt% NPs exhibited a fluid loss of 5.1 mL in the API filter press test. According to the Bingham plastic model, Muds E and F, containing 2.5 wt% and 3 wt% NPs, respectively, displayed the maximum shear stress vs. shear rate. This highlights the efficacy of nano-Fe2O3 in adjusting the properties of drilling fluids, presenting opportunities for enhanced performance and efficiency in drilling operations.

Biogenic synthesis and characterization of gold nanoparticles using transformed mesophilic Escherichia coli BL21 and thermophilic Thermus thermophilus HB27

Gold nanoparticles have numerous applications, many of which are notable in industries. The biosynthesis of gold nanoparticles offers an easy, effective, green, and eco-friendly approach. In organisms capable of synthesizing nanoparticles, enzymes and proteins are responsible for the structural and functional modifications that lead to their formation. These include ABC transporter, peptide-binding proteins, which are dependent on abiotic parameters. This study uses the purified ABC transporter, peptide-binding protein transformed from Thermus scotoductus SA-01 and expressed in mesophilic Escherichia coli BL21 and thermophilic Thermus thermophilus HB27 hosts for the biosynthesis of gold nanoparticles at different concentrations, temperatures, and pH values. Gold nanoparticle formation was evaluated with a range of gold (III) concentrations (0–10 mM), incubated at temperatures ranging from 30–85 ºC and pH levels from 3.6–9.0. Transmission electron microscopy (TEM), energy dispersive X-ray spectrometry (EDX), and UV–Vis absorption spectroscopy were used to characterise the formation of nanoparticles. In all of the protein reactions, UV–Vis absorbance peaks at approximately 520–560 nm confirmed the formation of gold nanoparticles. Optimum nanoparticle synthesis was observed at pH values ranging from 5.5 to 9.0, gold (III) solution (HAuCl4) concentrations from 0.5–2.0 mM, and a maximum temperature of 65ºC in the mesophilic host and 85ºC in the thermophilic host, indicating the significance of temperature in both hosts for the expression and bioactivity of the purified ABC transporter protein. However, the biogenic formation of gold nanoparticles using E. coli and T. thermophilus hosts was not monodispersed, suggesting a necessity for further development of the procedure.

Stable and Efficient Perovskite Solar Cells by Controlling the Crystal Growth via Introduction of Plasmonic TiN Nanoparticles

AbstractIncorporating noble‐metal plasmonic nanoparticles (NPs) enhances the optoelectronic properties of perovskite solar cells (PSCs) but at a higher cost. In this work, the overlooked potential of refractory plasmonic materials is highlighted as a cost‐effective alternative additive in PSC research. This investigation aims to stimulate interest in this area by showcasing the theoretical and practical impacts of TiN plasmonic NPs when integrated into PSCs. TiN plasmonic NPs present a cost‐effective yet underexplored option. This study explores the impact of TiN NPs on PSCs through theoretical and experimental approaches. Finite‐difference time‐domain (FDTD) optical simulations and empirical data indicate that TiN NPs increase absorption and reduce reflectance in PSCs, driven by surface plasmon resonance and the significant growth of perovskite grains from 450 to 1400 nm. These NPs also regulate the perovskite crystallization rate by adsorbing DMF/DMSO, fostering larger grain formation. Improved band alignment and decreased trap states enhance charge transport and diminish non‐radiative recombination losses. As a result, PSC efficiency with optimal TiN NP concentration increased from 19.07% to 21.37%. Additionally, TiN‐enhanced PSCs display better stability, retaining 98.1% of their original PCE after 31 days under ambient conditions.

Microporation-Mediated Transdermal Delivery of In Situ Gel Incorporating Etodolac-Loaded PLGA Nanoparticles for Management of Rheumatoid Arthritis.

Management of rheumatoid arthritis (RA) requires long-term administration of different medications since there has been no cure until now. Etodolac (ETD) is a nonsteroidal anti-inflammatory drug commonly used for RA management. However, its long-term administration resulted in severe side effects. This study aimed to develop a transdermal in situ gel incorporating ETD-loaded polymeric nanoparticles (NPs) to target the affected joints for long-term management of RA. Several PLGA NPs incorporating 1% ETD were prepared by nanoprecipitation and optimized according to the central composite design. The optimum NPs (F1) exhibited 96.19 ± 2.31% EE, 282.3 ± 0.62 nm PS, 0.383 ± 0.04 PDI, and -6.44 ± 1.69 ZP. A hyaluronate coating was applied to F1 (H-F1) to target activated macrophages at inflammation sites. H-F1 exhibited 287.4 ± 4.2 nm PS, 0.267 ± 0.02 PDI, and -23.7 ± 3.77 ZP. Pluronic F-127 in situ gel (H-F1G) showed complete gelation at 29 °C within 5 min. ETD permeation from H-F1G was sustained over 48 h when applied to microporated skin and exhibited significant enhancement of all permeation parameters. Topical application of H-F1G (equivalent to 8 mg ETD) to Wistarrat microporated skin every 48 h resulted in antirheumatic therapeutic efficacy comparable to commercial oral tablets (10 mg/kg/day).

Development, Optimization, and in vitro Evaluation of Silybin-loaded PLGA Nanoparticles and Decoration with 5TR1 Aptamer for Targeted Delivery to Colorectal Cancer Cells.

Chemotherapeutic agents often lack specificity, intratumoral accumulation, and face drug resistance. Targeted drug delivery systems based on nanoparticles (NPs) mitigate these issues. Poly (lactic-co-glycolic acid) (PLGA) is a well-studied polymer, commonly modified with aptamers (Apts) for cancer diagnosis and therapy. In this study, silybin (SBN), a natural agent with established anticancer properties, was encapsulated into PLGA NPs to control delivery and improve its poor solubility. The field-emission scanning electron microscopy (FE-SEM) showed spherical and uniform morphology of optimum SBN-PLGA NPs with 138.57±1.30nm diameter, 0.202±0.004 polydispersity index (PDI), -16.93±0.45mV zeta potential (ZP), and 70.19±1.63% entrapment efficiency (EE). The results of attenuated total reflectance-Fourier transform infrared (ATR-FTIR) showed no chemical interaction between formulation components, and differential scanning calorimetry (DSC) thermograms confirmed efficient SBN entrapment in the carrier. Then, the optimum formulation was functionalized with 5TR1 Apt for active targeted delivery of SBN to colorectal cancer (CRC) cells in vitro. The SBN-PLGA-5TR1 nanocomplex released SBN at a sustained and constant rate (zero-order kinetic), favoring passive delivery to acidic CRC environments. The MTT assay demonstrated the highest cytotoxicity of the SBN-PLGA-5TR1 nanocomplex in C26 and HT29 cells and no significant cytotoxicity in normal cells. Apoptosis analysis supported these results, showing early apoptosis induction with SBN-PLGA-5TR1 nanocomplex which indicated this agent could cause programmed death more than necrosis. This study presents the first targeted delivery of SBN to cancer cells using Apts. The SBN-PLGA-5TR1 nanocomplex effectively targeted and suppressed CRC cell proliferation, providing valuable insights into CRC treatment without harmful effects on healthy tissues.

Multi-approach synthesis of functionalized graphene oxide as reinforcement for polyethylene: Make a strong interaction

Nanoparticles need to be well dispersed in a polymer matrix to employ their advantages. Their agglomeration may cause defects and stress concentrations, deteriorating the final properties of polymer/graphene nanocomposite. Here graphene oxide (GO) was functionalized in several ways to improve its interaction with polyethylene and dispersion. Polyethylene-grafted maleic anhydride (PE-g-MA) with strong polar groups was used as the matrix to consider a high potential of enhanced interaction with the GO nanoparticles and therefore obtain a high-performance polyolefin composite. First, GO was produced by modified Hammer’s method from graphite. The GO was aminated by phenylene diamine and named FGO. Also GO was reduced chemically to obtain CRGO and thermally to obtain TRGO and then the recent ones were amino functionalized, named FCRGO and FTRGO, respectively. In another route GO was first amino functionalized and then was reduced chemically and named FCRGO+. The synthesized nanoparticles were characterized by visual tests, FTIR, XRD, SEM, and TGA analysis. Subsequently, the study investigates the fabrication of nanocomposites using these nanoparticles at 2 wt% in the PE-g-MA matrix by solution-casting method. The nanocomposites were characterized by optical microscopy, tensile and rheometric tests, FTIR, DSC, and SEM analysis. Based on the results, FCRGO+ was identified as the optimum nanoparticle having better dispersion, improved interfacial interaction, and stronger mechanical properties. The GO functionalized nanocomposites showed up to 36% in tensile modulus, 56% in tensile strength and 70% in elongation at break as compared to those of GO nanocomposites without functionalization of GO.

Optimization of Nanofluid Concentration for Energy Intensification in Corrugated Plate Type Heat Exchanger

The overall heat transfer coefficient of the heat exchanger will improve with an increase in the flow rate and concentration of nanofluid. But beyond an optimum nanoparticle concentration, the overall effectiveness seems to decrease due to an increase in pressure drop that consequently leads to an increase in pumping power. The novelty of the present work is to find the optimum concentration of CuO-Water nanofluid that exhibits the optimum heat transfer rate and global minimum pumping power, using both experimental and numerical study. The cold nanofluid and hot water entered the counter currently at 303.15 and 333.15 K respectively in the corrugated plate heat exchanger. It was observed from the experimental and numerical results that the values of overall heat transfer coefficient and pressure drop were increased monotonically (454–710 W/(m2-K) and 6–133 Pa respectively), with the increment in the concentration and flow rates of the nanofluid. Because of this trend, it was challenging to figure out the optimum nanofluid concentration using these parameters. Later, a procedure was presented to obtain an optimum concentration of nanofluid, to reduce the hot stream temperature by 288.15 K. The hydraulic power exhibited a global minimum at an optimum concentration of 0.5 vol% of nanofluid.

Experimental and data-driven analysis for predicting nanofluid performance in improving foam stability and reducing mobility at critical micelle concentration

Application of surfactant-based foam flooding is an effective approach to reduce mobility and control early breakthrough. Despite the proper performance of surfactant-based foams in decreasing the channeling of the flooded gas and water, high pressure, high temperature, and high salinity of the reservoirs put some limitations on the foam flooding efficiency. Nanoparticles are used to improve the quality of the foams, enhance stability, and transcend the limitations. Although there are many benefits of using nanoparticles in foam flooding, their performance at surfactant critical micelle concentration (CMC) is not fully investigated and the optimum nanoparticle concentration is not specified. In this study, an experimental investigation using nanosilica with surfactants at CMC to improve the stability (half-life) and mobility reduction factor (MRF) has been conducted. Furthermore, data from the literature were collected and analyzed to evaluate the change in MRF and stability for a nanofluid-based foam at CMC. Both experimental results and literature data showed that application of nanofluid-based foam is a successful approach to develop a more stable foam with lower mobility. Nanoparticle (NP) concentration is the dominant parameter at different salinities and temperatures that affects foam flow through porous media. The range of 0.2–0.4 wt% is the optimum nanoparticle concentration to develop a strong foam with acceptable performance in controlling mobility.

Graphene oxide-titanium oxide-polyaniline hybrid materials for high-performance dye-sensitized solar cells

A new solar cell that comprises a graphene oxide and titanium oxide nanoparticle (NP) composite with graphitized polyaniline (PANI) has been tested in polymer solar cells (PSCs). In this study, a series of conjugated polymers were synthesized and evaluated as the absorber and hole-transport layer materials in organic solar cells, demonstrating the significant impact of the chemical structure of the polymers on solar cell performance. The incorporation of graphene oxide (GOX) and titanium oxide TiO2 NP in conjugated polymers, particularly when graphitized within the PANI layer, led to improved open-circuit voltages compared to structurally similar polymers without NP. The morphology of the composite films was analyzed and related to the photovoltaic performance of polymers synthesized with polyaniline PANI-base and PANI-salt. Optimal NP addition in PANI-salt, PANI-base, PANI-base-TiO2, and PANI-base-GOX resulted in open-circuit voltages and efficiencies of 433 mV and 3.67%, 250 mV and 0.595%, 310 mV and 1.358%, and 520 mV and 2.366%, respectively. This study underscores the importance of polymer film uniformity in the performance of PSCs, with the highest efficiency obtained using a conjugated polymer with the best PANI-salt and PANI-base-GOX films. The research sheds light on the relationship between polymer structure and device photovoltaic performance, which is crucial for the design of new polymeric materials for efficient use and stable OSCs and PSCs.

Gastroprotective Chitosan Nanoparticles Loaded with Oleuropein: An In Vivo Proof of Concept.

Oleuropein is the main constituent of olive leaf extract, and it has shown antioxidant and gastroprotective properties against gastric ulcers. Chitosan nanoparticles are known for their mucoadhesive abilities, and consequently, they can increase the retention time of drugs in the gastrointestinal tract. Therefore, loading oleuropein onto chitosan nanoparticles is expected to enhance its biological efficiency. Oleuropein-loaded chitosan nanoparticles were prepared and characterized for particle size, surface charge, in vitro release, and anti-inflammatory activity. Their in vivo efficacy was assessed by measuring specific inflammatory and protective biomarkers, along with histopathological examination. The optimum oleuropein chitosan nanoparticles were cationic, had a size of 174.3 ± 2.4 nm and an entrapment efficiency of 92.81%, and released 70% of oleuropein within 8 h. They recorded a lower IC50 in comparison to oleuropein solutions for membrane stabilization of RBCs (22.6 vs. 25.6 µg/mL) and lipoxygenase inhibition (7.17 vs. 15.6 µg/mL). In an ethanol-induced gastric ulcer in vivo model, they decreased IL-1β, TNF-α, and TBARS levels by 2.1, 1.7, and 1.3 fold, respectively, in comparison to increments caused by exposure to ethanol. Moreover, they increased prostaglandin E2 and catalase enzyme levels by 2.4 and 3.8 fold, respectively. Immunohistochemical examination showed that oleuropein chitosan nanoparticles markedly lowered the expression of IL-6 and caspase-3 in gastric tissues in comparison to oleuropein solution. Overall, oleuropein chitosan nanoparticles showed superior gastroprotective effects to oleuropein solution since comparable effects were demonstrated at a 12-fold lower drug dose, delineating that chitosan nanoparticles indeed enhanced the potency of oleuropein as a gastroprotective agent.

The Influence of Fe2O3 Nanoparticles on Chlorella spp. Growth and Biochemicals Accumulation

The addition of metal oxide nanoparticles (NPs) to microalgae cultures have become of great interest since they can directly and/or indirectly interact with microalgae resulting in enhanced production of biomass and high-value added products. The physicochemical characteristics of the NPs, i.e., crystal phase, can differently influence microalgae metabolism, thus the synthesis of optimal NPs is mandatory to improve the value of microalgae biomass.This study aimed at assessing the effect of Fe2O3 NPs on Chlorella spp. cultures with and without carbonate supplementation to confirm their beneficial effect. First, Fe2O3 NPs were synthetized and two different annealing temperatures were implemented, 450 °C (Fe2O3-450) and 1000 °C (Fe2O3-1000), to obtain Fe2O3 NPs with different crystal phases. The NPs crystal phase was analyzed by X-ray diffraction and the presence of the γ- and α- phases on both NPs were confirmed. However, the Fe2O3-450 NPs presented a higher content of the γ- phase. Subsequently, the effect of the crystal phase of Fe2O3 NPs was assessed in Chlorella spp. cultures. The addition of Fe2O3-1000 NPs resulted in inhibition of Chlorella spp. On the other hand, the addition of Fe2O3-450 NPs recorded the carbohydrate enhancements > 91% in Chlorella spp. cultures. The indirect effect of the synthetized NPs was assessed in microalgae cultures without carbonate supplementation and the same tendency was observed. This study proves that Fe2O3-450 NPs directly and indirectly interact with microalgae, and can be used as a strategy to produce high-value biomass even in environments without carbonate supplementation.Graphical

Resonant optical trapping of Janus nanoparticles in plasmonic nanoaperture

Controlled trapping of light-absorbing nanoparticles with low-power optical tweezers is crucial for remote manipulation of small objects. This study takes advantage of the synergetic effects of tightly confined local fields of plasmonic nanoaperture, self-induced back-action (SIBA) of nanoparticles, and resonant optical trapping method to demonstrate enhanced manipulation of Janus nanoparticles in metallic nanohole aperture. We theoretically demonstrate that displacement of Au-coated Janus nanoparticles toward plasmonic nanoaperture and proper orientation of the metal coating give rise to enhanced near-field intensity and pronounced optical force. We also explore the effect of resonant optical trapping by employing a dual-laser system, where an on-resonant green laser excites the metal-coated nanoparticle, whereas an off-resonant near-infrared laser plays trapping role. It is found that, at the optimum nanoparticle configuration, the resonant optical trapping technique can result in threefold enhancement of optical force, which is attributed to the excitation of surface plasmon resonance in Janus nanoparticles. The findings of this study might pave the way for low-power optical manipulation of light-absorbing nanoparticles with possible applications in nanorobotics and drug delivery.

Experimental investigation of usage of POE lubricants with Al2O3, graphene or CNT nanoparticles in a refrigeration compressor.

In this study, the use of nanolubricants containing Al2O3, graphene, and carbon nanotubes (CNTs) at different mass fractions in a refrigeration compressor was experimentally investigated. The required electrical power of the compressor was measured to determine the effect of the use of nanolubricants. Nanoparticles used in the preparation of nanolubricants were gradually added to the lubricant to determine the optimum nanoparticle mass fraction for each nanoparticle type. Thus, it was found that the compressor operated safely and efficiently with nanolubricants. Furthermore, the optimum mass fractions were determined to be 0.750% for Al2O3, 0.250% for graphene, and 0.250% for CNTs for operating conditions of this study. As a result, the required electrical power of the compressor decreased by 6.26, 6.82, and 5.55% with the addition of Al2O3, graphene, and CNT nanoparticles at optimum mass fractions of 0.750, 0.250, and 0.250% to the lubricant, respectively, compared to the compressor using pure oil. Moreover, density and dynamic viscosity of the nanolubricant samples used in the experiments were also measured, and their kinematic viscosity, which is an important parameter for lubricants, was calculated. It was determined that the kinematic viscosity continuously increased with increasing nanoparticle fraction. In conclusion, nanolubricants containing nanoparticles above the optimum mass fraction increase the required electrical power of the compressor. It is concluded that nanoparticle fractions should not be used above the optimum value in nanolubricant applications.

Rheology‐cell structure correlation for foam processing of polypropylene‐titanium dioxide and polypropylene‐graphene nanocomposites

AbstractThis work focuses on understanding the effects of nanoparticle fillers (titanium dioxide (TiO2) and graphene) on foam processing of polypropylene(PP) and makes an attempt to establish a rheology‐cell size correlation for PP‐TiO2 and PP‐graphene nanocomposite foams. The establishment of such a correlation can help develop a precise model to predict optimum nanoparticle concentration in a polymer matrix to produce stable microcellular foams. The effects of adding TiO2 and graphene nanoparticles on nanocomposite properties are studied through their thermal, mechanical, and rheological analysis. The nanocomposite/PP foams are prepared at various conditions, and their morphology and density are studied to obtain an understanding of the cell structure as a function of added nanoparticles. The optimized size/structure has also been correlated in terms of rheological and mechanical properties of the prepared nanocomposites to study the effects of variation in rheological properties on the resultant cell structure of prepared foams. Through the current work it was found that particle type/size plays the dominant factor in determining the cell size of resultant foam, although when comparing foams with varying filler concentration, it was established that a decrease in viscosity and storage modulus would create more cell stability by decreasing the applied stress and would lead to smaller cells.Highlights Rheological property variation can directly affect the polymer foamability Foaming of polymers can be closely simulated using the Maxwell model for polymers Reduction in viscosity leads to smaller and stable cells during foaming Stress relaxation rate determines the cell stabilization during expansion Agglomerate size plays a crucial role in determining cell size

Screen-printed Sn-doped TiO2 nanoparticles for photocatalytic dye removal from wastewater: A technological perspective

TiO2 is widely used as a photocatalyst with a wide band gap, which limited its application. Ion doping and formulating a high-quality screen-printing paste enhance its features. However, the printability of objects for advanced application seems essential nowadays. In this research, the Sn-doped TiO2 nanoparticles were prepared through a sol-gel method followed by calcination at various temperatures of 450 °C, 550 °C, 650 °C, 750 °C, and 850 °C. Screen-printing pastes were prepared with 18 wt% of the synthesized Sn-doped TiO2 nanoparticles to evaluate photocatalytic activity. Finally, the prepared paste with optimum nanoparticle concentration was screen printed onto the microscope glass slides at various printing times (1, 3, and 5 runs) and annealed at 500 °C temperature to investigate the thickness of printed Sn-doped TiO2 nanoparticles effect. The photocatalytic activity and crystal structure of nano Sn-doped-TiO2 were characterized using photoluminescence (PL) spectroscopy and X-ray diffraction (XRD). Transmission electron microscopy (TEM) and scanning electron microscope (SEM) analyses were conducted to investigate the size and morphology of the prepared nanoparticles, respectively. The highest photocatalytic activity for the degradation of methylene blue was obtained at the calcination temperature of 450 °C.

Mathematical study of nanoparticle loaded in red blood cells for drug delivery in an artery with stenosis

Nanoparticles (NPs) offer a revolutionary platform in order to achieve targeted delivery for the treatment of cardiovascular diseases. Encapsulation of NPs or nanodrugs by the process of osmosis, inside red blood cells (RBCs), is a new technique in this regard. RBCs loaded with nanodrugs enhance the bio-availability and bio-compatibility. Mathematical model for the analysis of this RBCs loaded with NPs in blood has been developed for a catheterized artery with stenosis. The RBCs loaded with NPs in blood is described as nanofluid. The temperature and velocity of resultant nanofluid have been analyzed. Graphs have been plotted using MATLAB bvp4c for various values of particle radius and membrane thickness. It has been observed that RBCs loaded with NPs concentrate highly at the stenosis thus aid in dissolving it. Also, it has been examined that an optimum NP with a radius of 100 nm is suitable for the purpose. The outcomes shall be useful for the improvement of pharmacokinetics of nanodrugs.