Agitation Conditions Research Articles

Regime-switching energy price volatility: The role of economic policy uncertainty

This paper analyzes the volatility patterns of oil and natural gas prices in the United States and how they have changed due to economic policy uncertainty in the pre- and post-shale era. Using Markov-Switching GARCH models, we find evidence of heterogeneous volatility regimes for both commodities (i.e., high vs. low volatility). While the volatility persistence for oil is similar during the two sub-periods, significant changes have occurred to the natural gas market. Using quantile regressions, we find that economic policy uncertainty increases the probability of agitated market conditions of both markets, although this effect has weakened during the post-shale period.

Intensification of chondrocytes proliferation by microcarriers and wave-induced mixing: Reynolds number influence on CP5 cells growth

The growth of CP5 chondrocytes on microcarriers beads in a disposable bioreactor under various conditions of wave-assisted agitation has been compared and discussed. Influences of Reynolds number for liquid (ReL) and the kLa coefficient on intensification of the growth rate (μ) and the specific yield of biomass (Y*X/S) have been identified. Culture system has been established in ReadyToProcess WAVETM25 with a 2-litre flexible bag-like container. Cytodex 3 beads have been identified as the most suitable microcarrier fulfilled CP5 chondrocytes requirements. Based on simplified dimensionless correlations, the values of ReL (i.e., 510–10,208), and kLa coefficient (i.e., 2.83–13.55 h–1), have been both determined for various presets of the WAVE 25 system. The highest values of μ = 0.0129 h–1 and Y*X/S = 10.9 × 108 cells gglc–1 have been noted for culture performed under wave-induced agitation characterised by ReL equalled to 5104. The results might be highly applicable in scaling-up, and intensifying microcarrier-engineered bioprocesses focused on adherent mammalian or human cells maintained in disposable bioreactors.

Photocatalytic C-H bond activation by surface anchoring of [CoII(Saloph)(His)] complex on Ag-TiO2 nanocomposite

A novel heterojunction plasmonic photocatalyst [Co(Saloph)(His)]/Ag-TiO2 as a nanohybrid material was applied for the photocatalytic activity towards the C-H bond cleavage of alcohols to the aldehyde using different oxidants, O2, H2O2, or TBHP under irradiation of visible-light and NHPI as co-catalyst. It was synthesized by photo-deposition of metallic silver nanoparticles on titanium oxide surface and follow it, modification with cobalt(II) Saloph complex under ultrasonic agitation condition using histidine linker to reach a photocatalyst under 50 nm in size and band gap 2.64 eV. The [Co(Saloph)(His)]/Ag-TiO2 nanohybrid was characterized with EDS, XRD, DRS, FT-IR, PL spectroscopies, FESEM imaging, and BET technique. The size This three-component plasmonic photocatalyst revealed high photocatalytic efficiency with 95% conversion and 99% selectivity in aerobic conditions. The higher photocatalytic performance of [Co(Saloph)(His)]/Ag-TiO2 than the Co(Saloph)/TiO2 and Ag-TiO2 NPs should be related to the localized surface plasmonic resonance (LSPR) of these motives. So, this three-component nanohybrid provides an efficient interfacial electron transfer process through a synergistic effect that allows producing a nanocatalyst, with advantages of stability and fast selective C-H bond activation alcohols at ambient temperature using O2 as an inexpensive environmental friendly oxidant.

Sustainable removal of Ni(II) from waste water by freshly isolated fungal strains

The release of untreated wastewater containing biotoxic substances in the form of heavy metals is one of the most crucial environmental and health challenges faced by our community. The recent advances in microbes derived removal has propelled bioremediation as a better and effective alternative to conventional techniques. Present study investigates the detoxification mechanisms evolved by the nickel (Ni(II)) resistant fungal strains, isolated from the industrial drain sites. The molecular detailing of the isolated fungal isolates confirms their identity as Neurospora crassa and Aspergillus flavus. Laboratory-scale experiments have established influence of different ranges of dose, pH, time, and metal concentration on the removal and uptake trends. Further, the variations in the carbon and nitrogen sources and agitation conditions has revealed the best substratum for achieving optimum results for the industrial exploitation of these microbes. SEM micrographs and FTIR spectra elucidates the superficial alterations on the mycelium of the fungal isolates and the involvement of active functional groups in the bioremediation of Ni(II) respectively. Biosorption of Ni(II) on living biomass has followed the Langmuir adsorption model. The findings of the study have provided a promising insight in the simultaneous action of different mechanistic removal approaches to explore a large scale removal of Ni(II) from the waste generating industries.

Study on Dispersed-Phase Axial Dispersion in an Agitated–Pulsed Solvent Extraction Column with a Step Tracer Injection Technique

In this work, the residence time distribution (RTD) of the dispersed phase (aqueous phase) and continuous phase (organic phase) in an agitated-pulsed extraction column (APC) was measured online with a step tracer injection technique and the axial dispersion was subsequently calculated via RTD analysis. It was found that both the agitation speed and the pulsation intensity had noticeable effects on the axial dispersion of the dispersed phase, which escalates with the increase in the agitation speed and this is especially authentic at high pulsation intensity. The dispersed-phase axial dispersion coefficient also becomes higher with the increase in the dispersed-phase velocity. Compared with the dispersed-phase axial dispersion in the APC, the continuous-phase axial dispersion is 2-3 times higher. Empirical equations have been proposed to correlate the dispersed- and continuous-phase axial dispersion coefficients for variation of both agitation and pulsation conditions in APC. This study could be valuable for assessing the dispersed-phase axial dispersion in liquid-liquid extraction columns.

Modeling Amyloid Aggregation Kinetics: A Case Study with Sup35NM

Understanding the aggregation mechanism of amyloid proteins, such as Sup35NM, is essential to understanding amyloid diseases. Significant recent work has focused on using the fluorescence of thioflavin T (ThT), which undergoes a red shift when bound to amyloid aggregates, to monitor amyloid fibril formation. In the present study, the progression of the total mass of aggregates during fibril formation is monitored for initial monomer concentrations in order to infer the relevant aggregation mechanisms. This workflow was implemented using the amyloid-forming fragment Sup35NM under different agitation conditions and for initial monomer concentrations spanning 2 orders of magnitude. The analysis suggests that primary nucleation, monomeric elongation, secondary nucleation, and fragmentation might all be relevant, but their relative importance could not be determined unambiguously, despite the large set of high-quality data. Discriminating between the fibril-generating processes is shown to require additional information, such as a fibril length distribution. Using Sup35NM as a case study, a framework for fitting the parameters of arbitrary amyloid aggregation kinetics is developed based on a population balance model (PBM), which resolves not only the total aggregate mass (monitored experimentally via ThT fluorescence) but the entire fibril length distribution over time. In addition to the rich new set of ThT fluorescence data, we have reanalyzed a previously published aggregate size distribution using this method. With the size distribution, it was determined that in the reanalyzed in vitro experiment, secondary nucleation generated significantly fewer new Sup35NM fibrils than fragmentation. The proposed strategy of applying the same PBM to a combination of kinetic data from fluorescence monitoring and experimental fibril length distributions will allow the inference of aggregation mechanisms with far greater confidence than fluorescence studies alone.

Comparison of noninvasive, in-situ and external monitoring of microbial growth in fed-batch cultivations in Corynebacterium glutamicum

Automated bioprocess systems rely on accurate online measurements of cellular growth. In the present study, six sensors representing five different technologies, namely near-infrared absorbance, external non-invasive light scattering, back scattering reflectance, dielectric spectroscopy and exhaust gas analysis were evaluated in online monitoring of growth of the microbial cell factory Corynebacterium glutamicum. The signal outputs were monitored during the stationary growth phase of the cells under different conditions of agitation and aeration, conditions that pose potential interference with the in-situ signals. The random noise of the measurements was filtered using a Gaussian filter and the time derivatives were computed to obtain information of the microbial growth rate. Surprisingly, the signals of most probes under fed-batch cultivations of C. glutamicum were highly correlated with the stirring, but were mostly unaffected by the airflow, despite the increase in air bubbles that can cause measurement interference. Taken together, we show that an online estimation of growth of C. glutamicum based on the different sensor signals was possible with linear and multiple linear regression, correcting for the effect of stirring, and an estimation of growth rate was made accurate with an implementation of a Gaussian filter.

Production of Poly(3-hydroxybutyrate) (P(3HB)) from Different Agroindustry Byproducts by Bacillus megaterium

The use of plastics, replacing materials such as paper and glass, has become a staple of modern society. A possible alternative is the production of biopolymers, in which case polyhydroxyalkanoates (PHAs) tend to be the most studied class. Among the PHAs, poly(3-hydroxybutyrate) (P(3HB)) is one of the most studied. Bacillus megaterium can utilize a wide range of carbon sources to produce P(3HB) and display high resistance to osmotic pressure and temperature. There are few studies regarding the viability of confectionery wastewater (CWW) and rice parboiling water (RPW) in PHA production; however, data suggests they might be successfully used as culture media for microorganisms. Cultures of B. megaterium were conducted under a 22-factorial design of experiments with different agitation and airflow conditions using mineral medium added with CWW and RPW. Under maximized conditions, it was possible to obtain 7.55 g/L of dry cell biomass, with 50.1% P(3HB) content (3.78 g/L). Kinetic parameters of the maximized culture were also assessed, with the highest productivity (0.146 g/L·h) being found after 20 h of culture. Results found in the tests indicate that CWW and RPW can be used as culture media in P(3HB) production; however further studies are necessary to fully optimize the process, as well as to find alternatives to reduce the amount of residual total organic carbon (TOC) still present in the cultures.

Utilizing IoT to design a relief supply chain network for the SARS-COV-2 pandemic

The current universally challenging SARS-COV-2 pandemic has transcended all the social, logical, economic, and mortal boundaries regarding global operations. Although myriad global societies tried to address this issue, most of the employed efforts seem superficial and failed to deal with the problem, especially in the healthcare sector. On the other hand, the Internet of Things (IoT) has enabled healthcare system for both better understanding of the patient’s condition and appropriate monitoring in a remote fashion. However, there has always been a gap for utilizing this approach on the healthcare system especially in agitated condition of the pandemics. Therefore, in this study, we develop two innovative approaches to design a relief supply chain network is by using IoT to address multiple suspected cases during a pandemic like the SARS-COV-2 outbreak. The first approach (prioritizing approach) minimizes the maximum ambulances response time, while the second approach (allocating approach) minimizes the total critical response time. Each approach is validated and investigated utilizing several test problems and a real case in Iran as well. A set of efficient meta-heuristics and hybrid ones is developed to optimize the proposed models. The proposed approaches have shown their versatility in various harsh SARS-COV-2 pandemic situations being dealt with by managers. Finally, we compare the two proposed approaches in terms of response time and route optimization using a real case study in Iran. Implementing the proposed IoT-based methodology in three consecutive weeks, the results showed 35.54% decrease in the number of confirmed cases.

ICP-MS measurements of elemental release from two palladium alloys into a corrosion testing medium for different solution volumes and agitation conditions

Statement of problemThe in vivo release of Pd from palladium alloys into the oral environment and sensitivity reactions by patients has been of concern. However, little information is available about the variation in elemental release from different palladium alloys. PurposeThe purpose of this in vitro study was to compare the elemental release into a corrosion-testing medium from a high-palladium alloy (Freedom Plus, 78Pd-8Cu-5Ga-6In-2Au) and a Pd-Ag alloy (Super Star, 60Pd-28Ag-6In-5Sn) under different conditions. Material and methodsAlloys were cast into Ø12×1-mm-thick disks, subjected to simulated porcelain-firing heat treatment, polished, and ultrasonically cleaned in ethanol. Three specimens of each alloy were immersed for 700 hours in a solution for in vitro corrosion testing (ISO Standard 10271) that was maintained at 37 °C. Two solution volumes (125 mL and 250 mL) were used, and the solutions were subjected to either no agitation or agitation. Elemental compositions of the solutions were analyzed by using inductively coupled plasma-mass spectroscopy (ICP-MS). Concentrations of released elements from each alloy for the 2 solution volumes and agitation conditions were compared by using the restricted maximum likelihood estimation method with a 4-way repeated-measures ANOVA, the Satterwhite degrees of freedom method, a lognormal response distribution, and the covariance structure of compound symmetry. ResultsFor the 4 combinations of solution volume and agitation conditions, the mean amount of palladium released was 3 orders of magnitude less for the Pd-Ag alloy (0.009 to 0.017 μg/cm2 of alloy surface) compared with the Pd-Cu-Ga alloy (17.9 to 28.7 μg/cm2). Larger mean amounts of Sn, Ga, Ag, and In (0.29 to 0.39, 0.57 to 0.83, 0.71 to 1.08, and 0.91 to 1.25 μg/cm2, respectively) compared with Pd were released from the Pd-Ag alloy. Smaller amounts of Cu, Ga, and In (4.8 to 9.9, 5.9 to 12.8, and 4.2 to 9.5 μg/cm2, respectively) compared with Pd were released from the Pd-Cu-Ga alloy. The Ru released was much lower for the Pd-Ag alloy (0.002 μg/cm2) than the Pd-Cu-Ga alloy (0.032 to 0.053 μg/cm2). Statistically significant differences (P<.001) in elemental release were found for the factors of alloy and element and the alloy×element interaction. Significant differences were found for the solution volume (P=.022), solution volume×element interaction (P=.022), and alloy×solution volume×element interaction (P=.004). No significant effect was found for agitation condition. ConclusionsThe relative amounts of released elements from each alloy were not proportional to the relative amounts in the composition. The amounts of Pd and Ga released from the Pd-Cu-Ga alloy were consistent with the breakdown of a Pd2Ga microstructural phase and perhaps some dissolution of the palladium solid solution matrix. Precipitates, rather than the palladium solid solution matrix, appeared to undergo greater dissolution in the Pd-Ag alloy. The Pd-Ag alloy should have lower risk of adverse biological reactions than the Pd-Cu-Ga alloy.

Biomimetic silk biomaterials: Perlecan-functionalized silk fibroin for use in blood-contacting devices

Blood compatible materials are required for the development of therapeutic and diagnostic blood contacting devices as blood-material interactions are a key factor dictating device functionality. In this work, we explored biofunctionalization of silk biomaterials with a recombinantly expressed domain V of the human basement membrane proteoglycan perlecan (rDV) towards the development of blood compatible surfaces. Perlecan and rDV are of interest in vascular device development as they uniquely support endothelial cell, while inhibiting smooth muscle cell and platelet interactions. rDV was covalently immobilized on silk biomaterials using plasma immersion ion implantation (PIII), a new method of immobilizing proteins on silk biomaterials that does not rely on modification of specific amino acids in the silk protein chain, and compared to physisorbed and carbodiimide immobilized rDV. Untreated and treated silk biomaterials were examined for interactions with blood components with varying degrees of complexity, including isolated platelets, platelet rich plasma, blood plasma, and whole blood, both under agitated and flow conditions. rDV-biofunctionalized silk biomaterials were shown to be blood compatible in terms of platelet and whole blood interactions and the PIII treatment was shown to be an effective and efficient means of covalently immobilizing rDV in its bioactive form. These biomimetic silk biomaterials are a promising platform toward development of silk-based blood-contacting devices for therapeutic, diagnostic, and research applications. Statement of significanceBlood compatible materials are required for the development of therapeutic and diagnostic blood contacting devices as blood-material interactions are a key factor dictating device functionality. In this work, we explored biofunctionalization of silk biomaterials with a recombinantly expressed domain V (rDV) of the human basement membrane proteoglycan perlecan towards the development of blood compatible surfaces. Perlecan and rDV are of interest in vascular device development as they uniquely support endothelial cell, while inhibiting smooth muscle cell and platelet interactions. rDV was covalently immobilized on silk biomaterials using plasma immersion ion implantation (PIII), a new method of immobilizing proteins on silk biomaterials that does not rely on modification of specific amino acids in the silk protein chain. These biomimetic silk biomaterials are a promising platform toward development of silk-based blood-contacting devices for therapeutic, diagnostic, and research applications.

The role of surfaces on amyloid formation

Interfaces can strongly accelerate or inhibit protein aggregation, destabilizing proteins that are stable in solution or, conversely, stabilizing proteins that are aggregation-prone. Although this behaviour is well-known, our understanding of the molecular mechanisms underlying surface-induced protein aggregation is still largely incomplete. A major challenge is represented by the high number of physico-chemical parameters involved, which are highly specific to the considered combination of protein, surface properties, and solution conditions. The key aspect determining the role of interfaces is the relative propensity of the protein to aggregate at the surface with respect to bulk. In this review, we discuss the multiple molecular determinants that regulate this balance. We summarize current experimental techniques aimed at characterizing protein aggregation at interfaces, and highlight the need to complement experimental analysis with theoretical modelling. In particular, we illustrate how chemical kinetic analysis can be combined with experimental methods to provide insights into the molecular mechanisms underlying surface-induced protein aggregation, under both stagnant and agitation conditions. We summarize recent progress in the study of important amyloids systems, focusing on selected relevant interfaces.

How to evaluate the mass transfer resistances in dense solid–liquid suspensions

The dissolution of solids in slurry stirred tanks is affected from the solid concentration distribution to different extend, depending on the agitation conditions. In this work, the relationship between solid–liquid mixing and mass transfer is investigated by estimating the characteristic times of different phenomena: liquid mixing, solid dissolution, diffusion of the dissolved species in the vessel volume. The analysis is based on Electrical Resistance Tomography data collected during the simultaneous operations of dissolution and mixing. For dilute solid–liquid systems, the relative importance of the solid dissolution and the liquid mixing depends on the particle size and the impeller speed, while the diffusion in stagnant zones is often negligible. Instead, the diffusion mechanism has an important effect on mass transfer for dense systems, where strong axial gradients of solid concentration are established and the stirred tank volume can be divided into a lower zone containing a cloud of dense mixture and an almost stagnant clear liquid layer on top. Based on original and literature experimental data, a method for the main mass transfer resistance identification depending on the agitation condition, the solid volume fraction distribution and the soluble particle size is suggested.

Inhibition of alternative respiration system of Scheffersomyces stipitis and effect on glucose or xylose fermentation.

Scheffersomyces stipitis is a Crabtree-negative pentose fermenting yeast, which shows a complex respiratory system involving a cytochrome and an alternative salicylhydroxamic acid (SHAM)-sensitive respiration mechanism that is poorly understood. This work aimed to investigate the role of the antimycin A (AA) sensitive respiration and SHAM-sensitive respiration in the metabolism of xylose and glucose by S. stipitis, upon different agitation conditions. Inhibition of the SHAM-sensitive respiration caused a significant (P<0.05) decrease in glycolytic flux and oxygen consumption when using glucose and xylose under agitation conditions, but without agitation, only a mild reduction was observed. The combination of SHAM and AA abolished respiration, depleting the glycolytic flux using both carbon sources tested, leading to increased ethanol production of 21.05g/L at 250rpm for 0.5M glucose, and 8.3g/L ethanol using xylose. In contrast, inhibition of only the AA-sensitive respiration, caused increased ethanol production to 30g/L using 0.5M glucose at 250rpm, and 11.3g/L from 0.5M xylose without agitation. Results showed that ethanol production can be induced by respiration inhibition, but the active role of SHAM-sensitive respiration should be considered to investigate better conditions to increase and optimize yields.

Phenotypic properties and genotyping analysis of Bacillus cereus group isolates from dairy and potato products

Bacillus cereus group (B. cereus sensu lato) are ubiquitously distributed in diverse environments. In this study, eight isolates including B. cereus, B. paranthracis and B. toyonensis species, from dairy and potato products, were assessed for biofilm formation, sporulation and genetic information including biofilm-related genes and toxin genes. The isolates varied in their ability to form biofilm (either at the stainless steel-liquid-air interface or floating pellicles). The amounts of biofilms of B. cereus s.l., were increased when incubated in agitation condition varied between isolates. Sporulation within the planktonic and biofilm modes of growth was compared, suggesting that biofilm is a favourable environment for B. cereus s.l. to form spores. Whole genome sequencing (WGS) was used to compare these B. cereus s.l. isolates. New sequence types (STs) of B. cereus were found in this study. Isolates that shared similar genomes had different biofilm-forming and sporulation abilities. Most of isolates tested, possessed biofilm-related genes. Different combinations of toxin-producing genes were identified in different isolates, with all isolates containing nhe while only some contained hbl and cytK. None of the food isolates contained the emetic ces gene. This study highlights the diversity of B. cereus s.l. in biofilm formation, sporulation and their genetic variables.

Структура популяции Gluconacetobacter hansenii GH 1/2008 в статической культуре на различных источниках углерода

Структура популяции Gluconacetobacter hansenii GH 1/2008 в статической культуре на различных источниках углерода

Optimization of Aeration and Agitation for α-amylase production by Aspergillus flavus from water hyacinth

Amylases are a group of commercially important enzymes with various clinical, medical and biotechnological applications. The current study aims to optimize the agitation and aeration (oxygen transfer) conditions for α-amylase production by Aspergillus flavus using water hyacinth extract; as an available waste and very cheap nutritional substance, in a lab scale stirred tank bioreactor (submerged fermentation). Data showed that the maximal cell biomass and enzyme specific activity were reached at low aeration rate (0.5 v/v/m) and moderate agitation speed (200 rpm). The maximum specific amylase production rate has been reached after 24 hrs. In addition, it has been confirmed that scaling-up Aspergillus flavus does not, inversely, affect α-amylase productivity compared with flask level production. Aspergillus flavus has been approved as promising fungal isolate for production of a-amylase using water hyacinth for application in many fields.

Promising optimization of bacterial cytochrome P450BM3 enzyme production by engineered Escherichia coli BL21

Abstract P450BM3 monooxygenase enzymes are used as biocatalysts in biotechnology and engineering with an array of applications including drug and food ingredients synthesis. However, enzyme production efficiency is still not enough for catalysis reactions in large scale applications. Hence, it is important to optimize the culture conditions to increase maximum titers. The vast characterization of P450BM3 monooxygenases in the literature shows the great interest in their industrial applications. This work aims to provide a practical approach for improvement of biotechnological processes and accurate model parameters based on the optimum conditions. This study depicts the optimization of recombinant P450BM3 enzyme in engineered Escherichia coli BL21 in batch flasks and bioreactor, in which agitation, aeration and nutrient conditions were controlled. P450BM3 production in bioreactor was 41%-fold higher than in batch flasks. Our findings showed that P450BM3 production has been the highest ever reported for this enzyme. P450BM3 activity was improved by batch fermentations using glycerol 0.8%, FeCl3 0.12 g/L and 4 mL trace elements. The kinetic bioreactor parameters for enzyme production, KLa, R2 and PO2 were 0.025s−1, 0.99 and 21.17 mM O2/g, respectively. Therefore, this bioreactor cultivation allows providing promising experimental conditions for P450BM3 production in engineered E. coli, enabling this enzyme to be more applicable in many fields.

Influence of ClearT and ClearT2 Agitation Conditions in the Fluorescence Imaging of 3D Spheroids.

3D tumor spheroids have arisen in the last years as potent tools for the in vitro screening of novel anticancer therapeutics. Nevertheless, to increase the reproducibility and predictability of the data originated from the spheroids it is still necessary to develop or optimize the techniques used for spheroids’ physical and biomolecular characterization. Fluorescence microscopy, such as confocal laser scanning microscopy (CLSM), is a tool commonly used by researchers to characterize spheroids structure and the antitumoral effect of novel therapeutics. However, its application in spheroids’ analysis is hindered by the limited light penetration in thick samples. For this purpose, optical clearing solutions have been explored to increase the spheroids’ transparency by reducing the light scattering. In this study, the influence of agitation conditions (i.e., static, horizontal agitation, and rotatory agitation) on the ClearT and ClearT2 methods’ clearing efficacy and tumor spheroids’ imaging by CLSM was characterized. The obtained results demonstrate that the ClearT method results in the improved imaging of the spheroids interior, whereas the ClearT2 resulted in an increased propidium iodide mean fluorescence intensity as well as a higher signal depth in the Z-axis. Additionally, for both methods, the best clearing results were obtained for the spheroids treated under the rotatory agitation. In general, this work provides new insights on the ClearT and ClearT2 clearing methodologies and their utilization for improving the reproducibility of the data obtained through the CLSM, such as the analysis of the cell death in response to therapeutics administration.

Facile construction of thermo-responsive Pickering emulsion for esterification reaction in phase transfer catalysis system

In this paper, a thermo-responsive Pickering emulsion (PE) is constructed for the esterification reaction in the phase transfer catalysis (PTC) system. Silica nanoparticle modified by alkyl polyoxyethylene ether and tetrabutylammonium bromide (TBAB) is the highly efficient thermo-responsive Pickering emulsifier to stabilize the diisopropyl ketone-in-water emulsion. PEs can keep stable at room temperature for 3 days and demulsify only in the condition of elevated temperature and agitation, which causes the easy product separation and aqueous phase recycling. The adsorption of TBA+ and nonionic surfactant via electrostatic interaction and hydrogen bonding, respectively, can increase the hydrophobicity and the emulsifying capacity of silica nanoparticle. The ion-pair of TBA+ and reactant anion is generated and can be transferred into the organic phase, initiating the bond-forming reaction. The modifying effect of polyoxyethylene ether is weakened with the increase of temperature due to the loss of the hydrogen bonding interaction, resulting in the demulsification of PEs. Moreover, the cloud point of polyoxyethylene ether is the temperature for the complete separation of two phases. In this PTC system, the conversion rate for the esterification can reach to 92 % and the aqueous phase can be reused at least 5 times without sacrifice of the catalytic activity, demonstrating the potential application in industry.