Homogenization Speed Research Articles

Liquid surfactant membrane for lead separation from aqueous solution: Studies on emulsion stability and extraction efficiency

As an alternative extraction technique, Liquid Surfactant Membrane (LSM) reveals several benefits in terms of efficiency, cost effectiveness and easy demulsification post extraction, without altering the chemistry of the oil phase. In this study, the extraction and re-extraction of lead (Pb) from aqueous solution via the liquid surfactant membrane (LSM) technique are investigated. LSM contains Bis-2-ethylhexyl phosphoric acid (D2EHPA) as a carrier, H2SO4 as the internal phase, kerosene as the diluent stabilized by the surfactant (Span 80), all of which have been used to investigate its ability to extract the Pb from aqueous solutions. The effect of the Span 80 concentration, homogenizer speed, extractant concentration, the volume ratio of an organic to an internal phase (O/I), stripping phase (H2SO4) concentration and the emulsified time on the LSM stability and its extraction efficiency were studied. The reused oil phase showed an extraction percentage which was as high as the original oil phase. Besides, from the results it was clear that the removal of more than 98% of the Pb from feed solutions was possible, with the emulsion breakage below 2.8% after 10 min of contact time under the best-operating conditions for the original and reused emulsions.

Influence of pH and Salt Concentration on Pickering Emulsions Stabilized by Colloidal Peanuts.

Solid-stabilized emulsions commonly known as Pickering emulsions offer unique benefits such as superior stability and controlled permeability compared to conventional surfactant stabilized emulsions. In this article, the effect of pH, the electrolyte and particle concentration, homogenization speed, and volume fraction of oil on the formation, stability, and the microstructure of emulsion droplets stabilized by micron-size peanut-shaped hematite particles are investigated. The influence of surface charge of particles on emulsification is studied by varying the pH of the dispersing medium, the addition of an electrolyte or a combination of both. Stable O/W emulsions are formed only when the aqueous dispersions at intermediate pH between 4 and 11, and decane (2:1 volume ratio) are vigorously mixed. However, emulsions are not formed when the particles are highly charged that is, at pH 2 and 12. The presence of monovalent salt or high-speed homogenization assists the emulsion formation at pH 3, whereas their combination helps in emulsification at pH 2. However, neither the addition of an electrolyte nor the high-speed homogenization or their combination facilitates the formation of emulsions at pH 12. We show that the image-charge repulsion and the surface charge induced wettability change can explain the influence of both pH and salt concentrations on the formation of Pickering emulsions. Although oil-in-water emulsions typically cream because of the density difference, microscopy observations revealed the presence of a large number of small particle-covered oil droplets in the sediments of the emulsified samples. These drops are observed to be entrapped in dense-particle networks. This leads to a considerable reduction in the number of particles available for the stabilization of floating emulsion droplets and thus influences their size and surface coverage. The possibility of tailoring the stability, droplet size and, the surface coverage discussed in this article can play a crucial role in situations that demand controlled release of active components.

Coencapsulation of Polyphenols and Anthocyanins from Blueberry Pomace by Double Emulsion Stabilized by Whey Proteins: Effect of Homogenization Parameters.

Blueberry pomace is a rich source of high-value bioactive polyphenols with presumed health benefits. Their incorporation into functional foods and health-related products benefits from coencapsulation and protection of polyphenol-rich extracts in suitable carriers. This study aimed to create a water-in-oil-in-water (W1/O/W2) double emulsion system suitable for the coencapsulation of total phenolics (TP) and anthocyanins (TA) from a polyphenol-rich extract of blueberry pomace (W1). The effect of critical physical parameters for preparing stable double emulsions, namely homogenization pressure, stirring speed and time, was investigated by measuring the hydrodynamic diameter, size dispersity and zeta potential of the oil droplets, and the encapsulation efficiency of TP and TA. The oil droplets were negatively charged (negative zeta potential values), which was related to the pH and composition of W2 (whey protein isolate solution) and suggests stabilization by the charged whey proteins. Increasing W1/O/W2 microfluidization pressure from 50 to 200 MPa or homogenization speed from 6000 to 12,000 rpm significantly increased droplet diameter and zeta potential and decreased TA and TP encapsulation efficiency. Increasing W1/O/W2 homogenization time from 15 to 20 min also increased droplet diameter and zeta potential and lowered TA encapsulation efficiency, while TP encapsulation did not vary significantly. In contrast, increasing W1/O homogenization time from 5 to 10 min at 10,000 rpm markedly increased TA encapsulation efficiency and reduced droplet diameter and zeta potential. High coencapsulation rates of blueberry polyphenols and anthocyanins around 80% or greater were achieved when the oil droplets were relatively small (mean diameter < 400 nm), with low dispersity (<0.25) and a high negative surface charge (−40 mV or less). These characteristics were obtained by homogenizing for 10 min at 10,000 rpm (W1/O), then 6000 rpm for 15 min, followed by microfluidization at 50 MPa.

Lipid Based Aqueous Core Nanocapsules (ACNs) for Encapsulating Hydrophillic Vinorelbine Bitartrate: Preparation, Optimization, Characterization and In vitro Safety Assessment for Intravenous Administration.

Vinorelbine bitartrate (VRL) is an antimitotic agent approved by FDA for breast cancer and non-small cell lung cancer (NSCLC) in many countries. However, high aqueous solubility and thermo degradable nature of VRL limited the availability of marketed dosage forms. The current work is focused on the development of lipid based aqueous core nanocapsules which can encapsulate the hydrophilic VRL in the aqueous core of nanocapsules protected with a lipidic shell which will further provide a sustained release. The ACNs were prepared by double emulsification technique followed by solvent evaporation. Box Behnken Design was utilized to optimize the formulation and process variables. Thirteen batches were generated utilizing lipid concentration, surfactant concentration and homogenizer speed as dependent variables (at three levels) and particle size and encapsulation efficiency as critical quality attributes. The ACNs were characterized for particle size, zeta potential, polydispersity index (PDI), entrapment efficiency, morphology by Transmission Electron Microscopy (TEM) and in vitro release. The ACNs were further evaluated for safety against intravenous administration by haemocompatibility studies. Results demonstrated that lipidic nanocapsules enhanced the entrapment efficiency of VRL up to 78%. Transmission Electron Microscopy revealed spherical shape of ACNs with core-shell structure. The GMS-VRL-ACNs showed that release followed Korsemeyer peppas kinetics suggesting Fickian diffusion. Moreover, the compliance towards haemocompatibility studies depicted the safety of prepared nanocapsules against intravenous administration. ACNs were found to be promising in encapsulating high aqueous soluble anticancer drugs with enhanced entrapment and safety towards intravenous administration.

Effect of homogenization on binding-affinity of bacteriophage A511 in bovine milk fractions

The effect of milk homogenization conditions, including speed (17,400 rpm; 20,600 rpm; and 24,000 rpm) and time (5–25 min) on phage affinity in milk fractions was investigated. A broad host-range Listeria phage (A511) was inoculated. Milk fractions separation was carried out and phage enumeration was expressed as percentage of added phages. A maximum quantifiable phage of 42.6% was obtained in unhomogenized milk. Homogenization (5 min, at any speed) further reduced quantifiable phages (15.9–20.6%), but this percentage increased as homogenization time increased. Phage distribution in unhomogenized milk showed preference for fat followed by caseins. Milk homogenization caused milk fat to lose its ability to bind phages, inducing phages to bind to caseins preferentially. Whey was the milk fraction with the lowest affinity for phage. The effect of homogenization speed and time on phage affinity was only observed in caseins. A correlation between phages bound to caseins, fat surface area and fraction Φ was observed.

Isolation of mitochondrial subpopulations from skeletal muscle: Optimizing recovery and preserving integrity.

The subsarcolemmal (SSM) and interfibrillar (IFM) mitochondria in skeletal muscle appear to have distinct biochemical properties affecting metabolism in health and disease. The isolation of mitochondrial subpopulations has been a long-time challenge while the presence of a continuous mitochondrial reticulum challenges the view of distinctive SSM and IFM bioenergetics. Here, a comprehensive approach is developed to identify the best conditions to separate mitochondrial fractions. The main modifications to the protocol to isolate SSM and IFM from rat skeletal muscle were: (a) decreased dispase content and homogenization speed; (b) trypsin treatment of SSM fractions; (c) recentrifugation of mitochondrial fractions at low speed to remove subcellular components. To identify the conditions preserving mitochondrial function, integrity, and maximizing their recovery, microscopy (light and electron) were used to monitor effectiveness and efficiency in separating mitochondrial subpopulations while respiratory and enzyme activities were employed to evaluate function, recovery, and integrity. With the modifications described, the total mitochondrial yield increased with a recovery of 80% of mitochondria contained in the original skeletal muscle sample. The difference between SSM and IFM oxidative capacity (10%) with complex-I substrate was significant only with a saturated ADP concentration. The inner and outer membrane damage for both subpopulations was <1% and 8%, respectively, while the respiratory control ratio was 16. Using a multidisciplinary approach, conditions were identified to maximize SSM and IFM recovery while preserving mitochondrial integrity, biochemistry, and morphology. High quality and recovery of mitochondrial subpopulations allow to study the relationship between these organelles and disease.

INFLUENCE OF PROCESSING PARAMETERS ON RHEOLOGICAL BEHAVIOR OF BENTONITE-BASED PICKERING EMULSION

The aim of this work is to study the impact of processing parameters on the rheological properties of Pickering emulsions containing bentonite particles, CTAB, NaCl and soybean oil. Emulsification experiments were performed using mixing and homogenization at different speeds for 10 minutes. The effects of stirring speed and homogenization were investigated to determine the best conditions for producing a suitable Pickering emulsion for the intended application. In order to assess the influence of processing parameters on the Pickering emulsion rheological behavior average droplet size was measured and rheological tests were performed on all the emulsions samples. The rheological behavior of these emulsions is modeled by Casson's law. Results show that the stirring speed first decreases the average size of the droplets, and then an effect on the initial viscosity is observed. Increasing the stirring speed increases the values of the initial viscosity in contrast to the infinite viscosity which is influenced by the homogenization speed. On the other hand, these processing parameters significantly affect the values of the yield strength.&#x0D; Keywords: stirring speed, speed homogenization, rheological properties, Pickering emulsion.

Pickering emulsions stabilized by amphiphilic carbonaceous materials derived from wheat straw

Amphiphilic carbonaceous materials CM–1 and CM–2 were synthesized through the hydrothermal carbonization (HTC) of wheat straw powder. The samples were examined by scanning electron microscopy, Fourier–transform infrared spectroscopy and elemental analysis. The results showed that acid concentration and temperature greatly affected the surface properties and wettability of the carbonaceous materials during hydrothermal carbonization. The carbonaceous materials were then used to stabilize Pickering emulsions. CM–1 generated oil–in–water (O/W) Pickering emulsions, while CM–2 generated water–in–oil (W/O) Pickering emulsions. The effects of homogenization speed, particle concentration, dispersed phase to continuous phase volume ratio, pH, and oil type on the morphology, droplet size, size distribution, and stability of the emulsions were investigated. The obtained emulsions exhibited remarkable stability and were easily separated by filtration. This novel strategy for preparing emulsions using CM–1 and CM–2 was highly advantageous for the recovery and reuse of stabilizers.

Development of emulgel technology with saw palmetto extracts and of japanese sophora tincture for androgenetic alopecia treatment

Androgenic alopecia is a hair disease caused by an excessive influence of androgens on hair follicles, whose treatment requires long-term use of systemic and / or local action drugs. In Ukrainian pharmaceutical market for the androgenic alopecia treatment synthetic drug minoxidil is presented, which in the local long-term application causes many side effects. Therefore, the drugs development of plant origin is important.&#x0D; Taking into account of the androgenic alopecia pathogenesis, it was developed the emulgel composition and technology, which has Saw Palmetto extract and Sophora Japonica tincture as active ingredients. Their main biological active substances applying topically provide anti-androgenic, venotonic and follicles protective action.&#x0D; The qualities of dermatological remedies in large measure are influenced by their technological process. Therefore, the purpose of this investigation was the development of a rational emulgel technology with Saw Palmetto extract and Sophora Japonica tincture for the androgenic alopecia prevention and treatment.&#x0D; Samples of emulgel were manufactured with applying of different technological methods, namely: the method of emulsification, temperature, rate and duration of stirring. Prepared samples were controlled by uniformity, dispersion degree (with microscope Delta Optical Genetic Pro, Poland), pH (with pH-meter 150 MI, Russia) and structure viscosity (with rotational viscometer Brookfield VR-3000, Myr VISKOTECH, Spain).&#x0D; The optimal temperature for the emulgel preparation is 60 °C, since the melting temperature of cetyl alcohol (the most refractory component of the formulation) is 52 °C. When choosing the emulsifying method it was found that sequential addition of hydrophilic and oil phases to emulgators provided the highest dispersion and optimally rheological properties of the emulgel.&#x0D; The best homogenization speed, providing a high degree of dispersion and structural viscosity in the range 3 200–3 400 mPas, is 2 000 rev/min. The intensive size reduction of the dispersed phase was observed for 30 min stirring.&#x0D; As a result of investigation, it was established that the best method of emulsification was the sequential adding of oil and aqueous phase to the mixture of emulsifiers at the temperature – 60 °C, the speed – 2 000 rev/min for 30 min.

Optimization of Olive Oil-Based Nanoemulsion Preparation for Intravenous Drug Delivery.

A seven-factor Box-Behnken design was used for the optimized development of an olive oil-based nanoemulsion (NE) intended for intravenous drug delivery. The independent variables of olive oil concentration, tween 80 concentration, span 80 concentration, rate of adding of oil in aqueous phase, homogenization speed, homogenization time, and preparation temperature, were used as inputs of the factorial design. The response variables were mean droplet diameter, zeta potential (ZP), and polydispersity index (PDI). A quadratic, linear and 2FI model was established to predict the responses based on the multivariate model developed. The obtained experimental responses were in good agreement with predicted values from expert design, showing residual standard error (RSE) less than 10 %. TEM revealed that the optimized nanoemulsions were almost spherical with mean diameter about 40 nm. The developed formulation showed only about 4.6% of hemolysis and was safe for intravenous delivery. As well, the other in vitro characterization of the optimal nanoemulsion such as viscosity, percent transmittance, physical stability, and solubility study revealed it to be promising as an intravenous drug delivery system.

Encapsulation of Mangosteen Extract in Virgin Coconut Oil Based Nanoemulsions: Preparation and Characterization for Topical Formulation

Nanoemulsions containing extract of mangosteen (Garcinia mangostana L.) rind has been developed and characterized as a topical formulation. The encapsulation of mangosteen extract in nanoemulsions is considered a promising strategy to utilize the available bioactive compounds, particularly α-mangostin. In this study, a high-speed homogenization method was used to produce nanoemulsions of virgin coconut oil as the oil phase, combined Tween 80 and Span 80 as the oil-in-water surfactant, and distilled water as the aqueous phase. The homogenizer speed, oil and surfactant composition, and, hydrophilic lipophilic balance values of the surfactants were varied in order to get stable nanoemulsions formulation. The most stable nanoemulsion was obtained using a homogenizer speed of 8000 rpm, oil to surfactant volume ratio of 1:1.4, and surfactant hydrophilic lipophilic balance value of 12. Nanoemulsion formulation with average droplet size of 181 nm, zeta potential of -30.9 mV, and 0.01% α-mangostin loading was stable for 28 days without phase separation. Based on the accelerated stability test, the nanoemulsion shelf life is estimated to reach one year. The present study revealed that the virgin coconut oil-based nanoemulsion is a promising carrier of mangosteen extract for topical formulation.

Enhanced physicochemical stability and efficacy of angiotensin I-converting enzyme (ACE) - inhibitory biopeptides by chitosan nanoparticles optimized using Box-Behnken design

Bromelain-generated biopeptides from stone fish protein exhibit strong inhibitory effect against ACE and can potentially serve as designer food (DF) with blood pressure lowering effect. Contextually, the DF refer to the biopeptides specifically produced to act as ACE-inhibitors other than their primary role in nutrition and can be used in the management of hypertension. However, the biopeptides are unstable under gastrointestinal tract (GIT) digestion and need to be stabilized for effective oral administration. In the present study, the stone fish biopeptides (SBs) were stabilized by their encapsulation in sodium tripolyphosphate (TPP) cross-linked chitosan nanoparticles produced by ionotropic gelation method. The nanoparticles formulation was then optimized via Box-Behnken experimental design to achieve smaller particle size (162.70 nm) and high encapsulation efficiency (75.36%) under the optimum condition of SBs:Chitosan mass ratio (0.35), homogenization speed (8000 rpm) and homogenization time (30 min). The SBs-loaded nanoparticles were characterized for morphology by transmission electron microscopy (TEM), physicochemical stability and efficacy. The nanoparticles were then lyophilized and analyzed using Fourier transform infra-red spectroscopy (FTIR) and X-ray diffraction (XRD). The results obtained indicated a sustained in vitro release and enhanced physicochemical stability of the SBs-loaded nanoparticles with smaller particle size and high encapsulation efficiency following long period of storage. Moreover, the efficacy study revealed improved inhibitory effect of the encapsulated SBs against ACE following simulated GIT digestion.

Development of stable green emulsion liquid membrane process via liquid–liquid extraction to treat real chromium from rinse electroplating wastewater

This research addresses the development of stable green ELM process for chromium removal from industrial effluents where CrO42− and Cr2O72− is the predominant species. Types of carriers, diluents and stripping agents undergo screening via LLE process. Meanwhile, the parameters studied for ELM stability and extraction were surfactant and modifier concentrations, homogenizer speed and emulsifying time. The formulate condition of stable ELM process was 0.04M TOMAC in palm oil, 0.05M NaOH, 3% (w/v) Span 80, 5% (w/v) octanol, 10,000rpm homogenizer speed and 3min emulsifying time. At this condition, 97% of chromium was extracted with breakage rate of 10%.

Effect of homogenisation speed and centrifugation on particle size analysis of beef and the relationship with shear force

This study aimed to investigate the effect of homogenisation speed and centrifugation on particle size (PS) evaluation, and examine its relationship with shear force. Beef Longissimus lumborum (LL) muscle portions were randomly assigned to different ageing periods (0, 3 or 5 weeks), and tested for PS and shear force. The PS analysis was conducted at different homogenisation speeds (11,000, 16,000 and 19,000 rpm) with and without a centrifugation step prior to measurement. Samples homogenised at 11,000 rpm and not centrifuged gave PS results significantly different at each ageing time as did samples homogenised at 19,000 rpm and centrifuged. Overall samples homogenised at 11,000 rpm produced the lowest coefficient of variation for PS results. There was a significant correlation between PS and shear force across the different homogeniser speeds and centrifugation statuses. It is concluded that best practice when measuring PS in beef includes a homogeniser speed of 11,000 rpm with no centrifugation prior to measurement.

Carboxymethyl Assam Bora rice starch coated SPIONs: Synthesis, characterization and in vitro localization in a micro capillary for simulating a targeted drug delivery system

Carboxymethyl Assam Bora rice starch coated superparamagnetic iron oxide nanoparticles (CM-ABRS SPIONs) were chemically synthesized by co-precipitation method and particle size reduction was controlled by high energy homogenization process. Effects of various process variables (polymer concentration, homogenization speed and cycles) were optimized on the basis of average particle size (Z-average) and polydispersity index (PDI) of CM-ABRS SPIONs. The optimized CM-ABRS SPIONs were characterized for their particle size, surface morphology, electrokinetic potential, chemical interactions, crystallinity, magnetic properties, and targeting potential in presence of external magnetic field. In vitro localization of CM-ABRS SPIONs in a suspension of FITC (Fluorescein isothiocyanate) labeled RBCs (Red blood cells; hematocrit value; 45% (v/v)) was conducted inside a square glass capillary (500 × 500 μm2 cross section) in the presence of an externally applied magnetic field (Ms = 150 mT), simulating the case of magnetic drug targeting (MDT) approach. The aggregation dynamics of CM-ABRS SPIONs inside a micro capillary was observed with respect to time (t = 0 to 600 s), which shows proportionality to time of exposure to the externally applied magnetic field. This in vitro study acts as an important platform for design and optimization of active targeted drug delivery system.

Nanocrystalization of Pioglitazone by Precipitation Method.

Poor solubility in aqueous medium limits the use of many drugs. Different methods have been adopted to promote the rate of dissolution of slightly water soluble drugs. Crystallization improves solubility, and bioavailability by increasing the surface area of slightly water soluble drugs. Pioglitazone (PGZ), which is a class II Biopharmaceutical Classification System drug has a slight solubility in water and a slow rate of dissolution, which may have a negative effect on its metabolism leading to a therapeutic failure. The aim of this study was to improve the solubility of PGZ-HCl; an antidiabetic drug using precipitation method. Formulations were prepared with polyethylene glycol 6000 and isomalt using different speed of homogenizer and quantity of solvent by precipitation method. Drug-polymer interactions were examined using differential scanning calorimetry (DSC), and Powder X-Ray Diffraction (PXRD). Surface structure were shown by SEM photographs. The particle size was significantly decreased and solubility was enhanced with increase speed, ethanol solvent and increase stabilizer, however very high amount of stabilizer resulted in a decrease in solubility. This result however showed that solid dispersion technique is a potential method for increasing dissolution profile of a poorly aqueous soluble agent.

Antibacterial Activity of Emulsified Pomelo (Citrus grandis Osbeck) Peel Oil and Water-Soluble Chitosan on Staphylococcus aureus and Escherichia coli.

This study utilized pomelo steam distillation to isolate pomelo peel essential oil. The constituents were then analyzed through gas chromatography-mass spectrometry (GC-MS), and the antibacterial activity of the essential oil emulsions at different homogenizer speed conditions and concentrations of water-soluble chitosan (degree of acetylation, DA = 54.8%) against S. aureus and E. coli was examined. Analysis of the essential oil composition identified a total of 33 compounds with the main constituent, limonene accounting for 87.5% (940.07 mg/g) of the total. The pomelo peel oil was emulsified through homogenization at 24,000 rpm, resulting in a minimal inhibitory concentration (MIC) for E. coli that was 1.9 times lower than that of the essential oil without homogenization. In addition, a mixture of 0.4% essential oil emulsion and 0.03% water-soluble chitosan had the strongest synergetic antibacterial effect on S. aureus and E. coli at pH 7.4. In comparison with chitosan alone, the MIC value of this mixture was significantly 2.4 and 2.5 times lower. Hence, this study suggests using a mixture of emulsified pomelo peel oil and water-soluble chitosan to develop a novel natural food preservative, and that the processability of food, as well as the economic value of the byproducts of the Taiwan Matou pomelo and chitosan, could be increased.

INFLUENCE OF FORMULATION FACTORS ON THE SIZE OF NANOSTRUCTURED LIPID CARRIERS AND NANOEMULSIONS PREPARED BY HIGH SHEAR HOMOGENIZATION

Objective: The main purpose of this work was to elucidate the effect of certain formulation factors on the size of nanostructured lipid carriers (NLCs) and nanoemulsions (NEs) by using high shear homogenization method.Methods: NLCs and NEs were prepared by high shear homogenization method using different liquid lipids types such as (Dermarol DCO® and Dermarol CCT®) at different concentrations. The effect of different concentration ratios of Tween 80 to Span 20 (2.5/1, 5/1, 10/1, 15/1) w/w % and different homogenization speeds (12 000, 18 000 rpm) on the resulted particle size were also studied.Results: The results revealed that the optimum NLCs and NEs resulted when we use Dermarol CCT® with a concentration of 90 % as liquid lipid and decreasing surfactant ratio to (2.5/1) w/w % with increasing the homogenization speed to 18 000 rpm. Conclusion: NLCs and NEs were successfully prepared, and from this study, it can be concluded that NLCs have the optimum particle size than Nanoemulsions.

Rational design and evaluation of HBsAg polymeric nanoparticles as antigen delivery carriers

The present work is focused on the development and evaluation of single dose sustained-release Hepatitis B surface antigen (HBsAg) loaded nanovaccine for Hepatitis B. The conventional treatment suffers from repeated administration and hence requires a booster dose. Therefore, polymeric nanovaccine of HBsAg was developed by double emulsion solvent evaporation technique, utilizing central composite design for formulation optimization. The effects of independent variables (like polymer amount, stabilizer concentration, aqueous/organic phase ratio and homogenizer speed) were also studied on critical quality attributes like particle size and entrapment efficiency. Nanovaccine was characterized in terms of physicochemical parameters, release, internalization and in vivo immunological evaluation in BALB/c mice after administration by different routes such as oral, sub-cutaneous, nasal and intramuscular. The designed nanovaccine demonstrated nanometric size with smooth surface, negative zeta potential, maximum entrapment, sustained release and better internalization in macrophage and MRC-5 cell line. The immune-stimulating activity of nanovaccine administered by different routes was evaluated by measuring anti-HBsAg titre like specific immunoglobulin IgG and IgA response and cytokine level (interleukin-2, interferon-Y) measurement. The results indicated that the nanovaccine administered by intramuscular route produced better humoral as well as cellular responses and potential carriers for antigen delivery at single dose administration via intramuscular route.

Effect of mixing parameters, postcuring, and stoichiometry on mechanical properties of fiber reinforced epoxy–clay nanocomposites

The influence of processing variables was experimentally studied for glass fiber reinforced epoxy–clay nanocomposites manufactured using vacuum-assisted wet layup method. The tensile strength, flexural strength, and interlaminar shear strength of these nanocomposites were significantly influenced by the processing variables including the temperature of resin–clay mixture, speed of homogenization, and ultrasonic probe amplitude during premixing of clay minerals in epoxy. The glass transition temperature of glass fiber reinforced composites increased with incorporation of clay minerals in epoxy. Also, the postcuring of the laminates was carried out at three different temperatures, e.g. 100, 130, and 150 ℃ for 3 h. A decrease in tensile modulus, tensile strength, and flexural strength of nanocomposites postcured at 130 and 150 ℃ was observed. Also, the use of non-stoichiometric epoxy resin and hardener ratios had an adverse effect on mechanical properties of fiber reinforced epoxy–clay nanocomposites. In fiber reinforced composites incorporating clay minerals, a uniform dispersion of clay minerals besides a strong interfacial adhesion between clay minerals and polymer and optimum conditions of curing of matrix is a crucial aspect for improved performance over conventional fiber reinforced composites.