Bicarbonate Production Research Articles

Experimental investigation of a new ammonium bicarbonate reactor induced with an electromagnetic heater

This work presents the experimental study conducted on a newly developed ammonium bicarbonate reactor for the purposes of carbon capturing and utilization. This reactor produces ammonium bicarbonate with the assistance of an industrial catalyst (such as steel) and an electromagnetic induction heater for enhancing the production of ammonium bicarbonate. The experimental setup is prepared to have three cases which are the baseline case, catalyst case, and induction heating case. These three cases are compared in terms of ammonium bicarbonate production by mass and the ratio of actual mass produced over their theoretical limits. The results of our present experiments show that the steel catalyst is proven to be an effective catalyst as it helps improve the production of ammonium bicarbonate by a factor of 1.56 when the inlet exhaust gases have 30% mol of carbon dioxide compared to the baseline case. In addition, the ammonium bicarbonate production improves by a factor of 2.56 when a steel catalyst and an induction heater are used together compared to the baseline case where the carbon dioxide composition entering the reactor is 80%mol. These results present the promising potential for implementing a cheap catalyst and an electromagnetic induction heater for the enhancement of carbon capture and utilization reactors.

Innovation in valorization of cow manure: Higher hydrolysis, methane production and increased phosphorus retention using UASB technology

Cow manure has potential to serve as a sustainable secondary fuel and phosphorus resource and cut our reliance on finite primary resources. The efficient and sustainable valorization of cow manure faces compositional challenges because of a high solids content, the lack of soluble phosphorus, fine struvite particles being the main phosphorus species and high bicarbonate concentrations. Addition of calcium could result in higher methane production and conversion of struvite to calcium phosphate. To investigate this, cow manure was digested in two up-flow anaerobic sludge blanket reactors for 456 days, one with and one without CaCl2 addition. A positive effect of calcium addition was found for hydrolysis (29 % without calcium and 67 % with calcium), methane production (136 L-CH4 kgVS-1 without calcium and 301 L-CH4 kgVS-1 with calcium) and sludge bed development. Although calcium was added in a 3:1 ratio to phosphorus, it did not result in recrystallization of struvite to calcium phosphate. Instead, it precipitated as calcium carbonate, which was further induced by additional bicarbonate production through higher hydrolysis and methane production. Still, calcium addition caused better phosphorous removal (from 38 % to 61 %), which is attributed to the enhanced sludge bed capturing and accumulating both the calcium carbonate and struvite fines. Higher methane production and improved phosphorus retention enables better valorization of cow manure. The access to resources from cow manure through this technology can contribute to the circularity of agriculture and save on finite natural resources.

Life cycle assessment of a novel tannin-boron association for wood protection

In these studies of fix boron compounds, associations between tannins and boron (TB) in the form of boric acid appear to be of interest. These TB associations allow the use of boron at very low levels (in compliance with EU restrictions, 2008/58/EC) and limit boron leaching which maintains biological resistance and fire retardant properties. As a consequence, TB wooden products present an extended service life compared to boron compounds alone and were designed to be environmentally-friendly wood protection systems. A follow-up of tannin‑boron use identified the environmental impacts using a life cycle assessment (LCA). This LCA was performed on tannin‑boron preservative products as well as several industrial preservative-treated timbers and concrete used in the landscape. Cr-containing inorganic salt and an alkaline copper quaternary preservative formulation, as well as concrete, have been used as referential materials to compare the environmental footprint with the tannin‑boron treated system. A model was created with life cycle stages used to calculate inputs and outputs during raw material extraction, supplier transportation, manufacturing process, distribution, disposal transportation and processing. Tannin production data were based on Vieira et al. in the field of condensed tannin extraction. However, the extracted tannin in the extraction yield, the inorganic salt, and the process applied are not perfectly comparable with the extraction conditions industrially applied for the Mimosa (Acacia mearnsii) extract which is the major constituent of the TB formulations. The latter is counter-current water extracted without any chemicals or with a limited amount of NaHSO3 or Na2SO3 (at 0.5 % to 1 %) — at a temperature of 70–90 °C. Unfortunately these parameters cannot be elaborated by the LCA program because there is no data available for the production of Na bisulphite or Na bicarbonate in the LCI data used. Other input data were sourced from the ecoinvent v3.8 database. The ReCiPe midpoint method was used to assess the environmental footprint and the CED method was chosen to analyze a general view of the energy-related environmental impacts in the life cycle. Overall, the results demonstrated that tannin‑boron preservatives can be regarded as a low-environmental impact formulation. Additionally, an economic analysis of the development of a commercially-viable tannin‑boron preservative would now be timely.

Optimization of Sodium Bicarbonate Production from Ammonium Hydroxide Using a Froth Flotation Column

AbstractSodium bicarbonate is produced by the Solvay process from salt (NaCl), ammonia gas (NH3), and CO2. Here, the Solvay process was modified by using ammonium hydroxide (NH4OH) liquid to replace NH3. To increase the yield of sodium bicarbonate, a froth flotation column was used. This column can generate microbubbles of CO2, which increases the CO2 conversion. The parameters were studied using response surface methodology (RSM) with a central composite design of experiments. Based on the RSM analysis, the optimum conditions were identified. Analysis of variance shows that the reaction time is the most significant parameter affecting the production of sodium bicarbonate. Empirical quadratic multivariable equation models were obtained with R2 = 0.94. The heavy metal‐free product can be used as a food additive.

A novel microbial-assisted method for sodium bicarbonate production – Cleaner production, safe and facile synthesis

The human tendency to new, cleaner, and safer methods for the production of materials has led to extensive eco-friendly studies. Herein, urea ((NH2)2CO) was exposed to bio-catalyzed urease enzyme from Sporosarcina pasteurii (formerly known as Bacillus pasturii). After hydrolysis of urea, the gassing of CO2 led to the production of sodium bicarbonate (NaHCO3). The final product was validated for its crystallographic, microstructural, and elemental properties through X-ray diffraction (XRD), carbon-hydrogen-nitrogen (CHN) elemental analysis, field-emission scanning electron microscopy (FE-SEM), X-ray fluorescence (XRF) spectroscopy, and energy-dispersive X-ray (EDX) spectroscopy. These results, along with the chemical evaluation of chloride ion, proved that NaHCO3 was the major compound with a purity of > 76 %. This finding confirmed that cleaner and facile production of NaHCO3 is possible by our defined novel enzymatically-modified Solvay method. Besides removing hazardous materials before and after the process (raw materials and residues), this method simultaneously highlights the potential for converting CO2 captured from the environment or gases released from different industries to NaHCO3 a highly applicable material for pharmaceuticals, food, and other industries.

MO097: Idiopathic Hypercalciuria: Calciuria and Citraturia Evolution. A 20-year Longitudinal Study

Abstract BACKGROUND AND AIMS Reduction and normalization of calciuria in children with idiopathic hypercalciuria (IH) was published by Aladjem et al. (1996). The association between IH and hypocitraturia was described in two Brazilian studies; however, further studies are needed to determinate the caracteristics of its relation. We studied calcium and citrate urinary excretion in children diagnosed with IH and followed up until adulthood. METHOD: A total of 34 patients (12 M and 22 F) were studied. IH diagnosis was performed at the age of 7.9 ± 3 years (range: 1–14). Hypercalciuria was defined as urinary calcium excretion of >4 mg/kg/day in two successive samples. Calciuria and citraturia were collected in the first urine sample of the day at the same time as bone densitometry was performed. Three determinations were made: the first (D1) at age 10.5 ± 2.7 years (range: 6.5–16.8), the second (D2) at age 14.5 ± 2.7 years (range: 9.9–19.5) and the third (D3) at age 28.2 ± 2.8 years (range: 24.1–35.9). RESULTS: Calcium/creatinine ratio (P = 0.005) and citrate/creatinine ratio (P < 0.001) reduction during follow up was observed. In addition, we observed an increase in the calcium/citrate ratio (P = 0.008). Patients with a calcium/creatinine ratio higher than 0.20 mg/mg decreased from 100% at diagnosis to 52.9% (18/34) on D1 and to 26.5% (9/34) on D2 and 23.5% (8/34) in adulthood (D3). Lithogenetic risk decreased from diagnosis (15/28; 53.6%) to D1 (13/32; 40.6%) and D2 (8/28; 28.6%) but increased in adulthood (21/30; 70%). CONCLUSION It is difficult to explain why some IH patients present a decrease in both calcium and citrate excretion in adolescence and early adulthood, which has an impact on lithogenic risk. The interpretation of these results is complex. Bone is the largest reservoir of alkaline salts in the body. Our hypothesis is that late hypocitraturia observed in patients with IH would be an indirect sign of high functional osteoblastic activity. Increased proximal tubular citrate reabsorption would denote an increased bicarbonate production, which is necessary as osteoblastic activity increases, thus requiring increased inputs of alkali, calcium (normalized calciuria) and phosphate. Another option could be the development of incomplete distal renal tubular acidosis.

Hyperpolarized 13C MRI Reveals Large Changes in Pyruvate Metabolism During Digestion in Snakes

PurposeHyperpolarized 13C MRI is a powerful technique to study dynamic metabolic processes in vivo; but it has predominantly been used in mammals, mostly humans, pigs, and rodents.MethodsIn the present study, we use this technique to characterize the metabolic fate of hyperpolarized [1‐13C]pyruvate in Burmese pythons (Python bivittatus), a large species of constricting snake that exhibits a four‐ to tenfold rise in metabolism and large growth of the visceral organs within 24–48 h of ingestion of their large meals.ResultsWe demonstrate a fivefold elevation of the whole‐body lactate‐to‐pyruvate ratio in digesting snakes, pointing to a large rise in lactate production from pyruvate. Consistent with the well‐known metabolic stimulation of digestion, measurements of mitochondrial respiration in hepatocytes in vitro indicate a marked postprandial upregulation of mitochondrial respiration. We observed that a low SNR of the hyperpolarized 13C produced metabolites in the python, and this lack of signal was possibly due to the low metabolism of reptiles compared with mammals, preventing quantification of alanine and bicarbonate production with the experimental setup used in this study. Spatial quantification of the [1‐13C]lactate was only possible in postprandial snakes (with high metabolism), where a statistically significant difference between the heart and liver was observed.ConclusionWe confirm the large postprandial rise in the wet mass of most visceral organs, except for the heart, and demonstrated that it is possible to image the [1‐13C]pyruvate uptake and intracellular conversion to [1‐13C]lactate in ectothermic animals.

Concentration-dependent effects of dichloroacetate in type 2 diabetic hearts assessed by hyperpolarized [1-13 C]-pyruvate magnetic resonance imaging.

Personalized medicine or individualized therapy promises a paradigm shift in healthcare. This is particularly true in complex and multifactorial diseases such as diabetes and the multitude of related pathophysiological complications. Diabetic cardiomyopathy represents an emerging condition that could be effectively treated if better diagnostic and, in particular, better therapeutic monitoring tools were available. In this study, we investigate the ability to differentiate low and high doses of metabolically targeted therapy in an obese type 2 diabetic rat model. Low-dose dichloroacetate (DCA) treatment was associated with increased lactate production, while no or little change was seen in bicarbonate production. High-dose DCA treatment was associated with a significant metabolic switch towards increased bicarbonate production. These findings support further studies using hyperpolarized [1-13 C]-pyruvate magnetic resonance imaging to differentiate treatment effects and thus allow for personalized titration of therapeutics.

Recovery of baking soda from reverse osmosis reject of desalination plant using carbon dioxide gas

The extraction of baking soda from the reverse osmosis (RO) reject of desalination plant using CO2 gas has been studied. The novel idea of using amino acid additives to improvise the conventional Solvay process and thereby increasing the Na+ recovery efficiency has been explored. Three amino acid additives namely Glycine, L-Arginine and L-Alanine are studied for their effect on increasing Na+ recovery and the best suitable additive is selected. Necessary parameters governing the recovery such as concentration of amino acid, reaction temperature, flowrate of CO2 and carbonation time have been optimized with a view to get a maximum recovery efficiency by the modified Solvay process. Under the optimized conditions maximum sodium recovery of 70% is obtained. The modified Solvay process has yielded a higher recovery efficiency compared to the conventional Solvay process (33%). Amino acid additive (alanine) has increased the conversion efficiency and has also helped in reducing the ammonia requirement of the process. The results obtained show a feasible way to protect our environment by utilizing the reject of the desalination plant and the industrial waste gas carbon dioxide in bicarbonate production.

Establishment of an RI for the urine ammonia-to-creatinine ratio in dogs.

BackgroundAmmonia is produced and excreted by the kidney, contributing to systemic acid‐base homeostasis through the production of bicarbonate. Disorders of acid‐base balance can lead to many clinical problems and measuring ammonia excretion helps in determining if the kidneys are responding to acid‐base challenges appropriately. Reference intervals are integral to clinical decision‐making, and there is no current RI for the urine ammonia‐to‐creatinine ratio (UACR) in dogs.ObjectiveThis study aimed to generate an RI for the UACR in healthy adult dogs.MethodsThe study used adult, client‐owned dogs that were presented to the University of Florida Primary Care and Dentistry service (n = 60). Physical examinations were performed and serum chemistry and urinalysis samples were obtained. Urine ammonia and creatinine concentrations were determined. Dogs were excluded if there were significant abnormalities in either their urinalysis or serum chemistry results. The RI for the UACR was calculated according to the recommendation of the American Society for Veterinary Clinical Pathology. Data were evaluated for correlation with serum bicarbonate, weight, age, and sex.ResultsThe RIs for the UACR were 0.16‐23.69 with 90% confidence intervals for the lower and upper limits of (0.13‐1.17) and (20.50‐23.75), respectively. No significant impact of age, sex, or weight was found. There was no discernable relationship between serum bicarbonate and UACR.ConclusionsEstablishing an RI for UACR in healthy adult dogs will allow for further studies to determine if alterations are observed during specific disease states.

A Combined Chemical-Electrochemical Process to Capture CO2 and Produce Hydrogen and Electricity

Several carbon sequestration technologies have been proposed to utilize carbon dioxide (CO2) to produce energy and chemical compounds. However, feasible technologies have not been adopted due to the low efficiency conversion rate and high-energy requirements. Process intensification increases the process productivity and efficiency by combining chemical reactions and separation operations. In this work, we present a model of a chemical-electrochemical cyclical process that can capture carbon dioxide as a bicarbonate salt. The proposed process also produces hydrogen and electrical energy. Carbon capture is enhanced by the reaction at the cathode that displaces the equilibrium into bicarbonate production. Literature data show that the cyclic process can produce stable operation for long times by preserving ionic balance using a suitable ionic membrane that regulates ionic flows between the two half-cells. Numerical simulations have validated the proof of concept. The proposed process could serve as a novel CO2 sequestration technology while producing electrical energy and hydrogen.

Investigation of the interaction of CO2 and NH3 in the gaseous phase

In the modern world, the issue of increasing the production of soda ash is acute. However, the mechanism of chemisorption CO2 by the ammoniated brine and does not take into account the share of the gas reaction. Regularities of the mechanism and kinetics of the gas-phase reaction of the interaction of the mixture CO2 and NH3 must be taken into account in the conditions of soda ash production both at the stages of ammoniated brine production and at the stages of sodium bicarbonate production.

Hyperpolarized 13C MR Spectroscopy Depicts in Vivo Effect of Exercise on Pyruvate Metabolism in Human Skeletal Muscle.

Background Pyruvate dehydrogenase (PDH) and lactate dehydrogenase are essential for adenosine triphosphate production in skeletal muscle. At the onset of exercise, oxidation of glucose and glycogen is quickly enabled by dephosphorylation of PDH. However, direct measurement of PDH flux in exercising human muscle is daunting, and the net effect of covalent modification and other control mechanisms on PDH flux has not been assessed. Purpose To demonstrate the feasibility of assessing PDH activation and changes in pyruvate metabolism in human skeletal muscle after the onset of exercise using carbon 13 (13C) MRI with hyperpolarized (HP) [1-13C]-pyruvate. Materials and Methods For this prospective study, sedentary adults in good general health (mean age, 42 years ± 18 [standard deviation]; six men) were recruited from August 2019 to September 2020. Subgroups of the participants were injected with HP [1-13C]-pyruvate at resting, during plantar flexion exercise, or 5 minutes after exercise during recovery. In parallel, hydrogen 1 arterial spin labeling MRI was performed to estimate muscle tissue perfusion. An unpaired t test was used for comparing 13C data among the states. Results At rest, HP [1-13C]-lactate and [1-13C]-alanine were detected in calf muscle, but [13C]-bicarbonate was negligible. During moderate flexion-extension exercise, total HP 13C signals (tC) increased 2.8-fold because of increased muscle perfusion (P = .005), and HP [1-13C]-lactate-to-tC ratio increased 1.7-fold (P = .04). HP [13C]-bicarbonate-to-tC ratio increased 8.4-fold (P = .002) and returned to the resting level 5 minutes after exercise, whereas the lactate-to-tC ratio continued to increase to 2.3-fold as compared with resting (P = .008). Conclusion Lactate and bicarbonate production from hyperpolarized (HP) [1-carbon 13 {13C}]-pyruvate in skeletal muscle rapidly reflected the onset and the termination of exercise. These results demonstrate the feasibility of imaging skeletal muscle metabolism using HP [1-13C]-pyruvate MRI and the sensitivity of in vivo pyruvate metabolism to exercise states. © RSNA, 2021 Online supplemental material is available for this article.

Proteomic analysis of pikeperch seminal plasma provides novel insight into the testicular development of domesticated fish stocks

Control of the reproduction of domesticated stocks is considered a prerequisite for aquaculture development of pikeperch. However, knowledge about the physiology of the captive pikeperch male reproductive system and the biology of semen is very limited, especially regarding protein characteristics. The aims of our study were to characterize pikeperch sperm quantity and quality parameters and to analyze changes in the proteome of the same males spawned for the first and second times. Moreover, attempts were made to generate the first proteomic library of seminal plasma proteins. Semen collected during the first spawning season was characterized by lower sperm concentration and volume than for the second season. Using mass spectrometry-based label-free quantitative proteomics, we identified 850 proteins in the seminal plasma of pikeperch from both spawning seasons, and 65 seminal proteins were found to be differentially abundant between the first and second spawning seasons. The majority of differentially abundant proteins were involved in stress and immune responses, developmental processes, cofactor metabolic processes, proteolysis, cellular oxidant detoxification and organization of the extracellular matrix (ECM). In addition, several proteins unique to pikeperch seminal plasma were identified, including antifreeze proteins, hibernation-specific plasma proteins, lectins and vitellogenin. In summary, our results indicate that males that spawned for the first time were characterized by incompletely mature gonads and the expression of proteins associated with the early phase of spermatogenesis and ECM organization. On the other hand, males that spawned for the second time exhibited advanced gonadal maturation and expression of proteins related to the late stage of spermatogenesis and sperm maturation, including regulation of reactive oxygen species generation, bicarbonate production, sperm elongation and separation. The identification of a large number of seminal plasma proteins provides a valuable resource for understanding the functions of seminal plasma and the molecular mechanisms involved in testicular development and maturation in domesticated fish, which is a prerequisite for better control of reproduction in captivity.

LDH and PDH Activities in the Ischemic Brain and the Effect of Reperfusion-An Ex Vivo MR Study in Rat Brain Slices Using Hyperpolarized [1-13C]Pyruvate.

Ischemic stroke is a leading cause for neurologic disability worldwide, for which reperfusion is the only available treatment. Neuroimaging in stroke guides treatment, and therefore determines the clinical outcome. However, there are currently no imaging biomarkers for the status of the ischemic brain tissue. Such biomarkers could potentially be useful for guiding treatment in patients presenting with ischemic stroke. Hyperpolarized 13C MR of [1-13C]pyruvate is a clinically translatable method used to characterize tissue metabolism non-invasively in a relevant timescale. The aim of this study was to utilize hyperpolarized [1-13C]pyruvate to investigate the metabolic consequences of an ischemic insult immediately during reperfusion and upon recovery of the brain tissue. The rates of lactate dehydrogenase (LDH) and pyruvate dehydrogenase (PDH) were quantified by monitoring the rates of [1-13C]lactate and [13C]bicarbonate production from hyperpolarized [1-13C]pyruvate. 31P NMR of the perfused brain slices showed that this system is suitable for studying ischemia and recovery following reperfusion. This was indicated by the levels of the high-energy phosphates (tissue viability) and the chemical shift of the inorganic phosphate signal (tissue pH). Acidification, which was observed during the ischemic insult, has returned to baseline level following reperfusion. The LDH/PDH activity ratio increased following ischemia, from 47.0 ± 12.7 in the control group (n = 6) to 217.4 ± 121.3 in the ischemia-reperfusion group (n = 6). Following the recovery period (ca. 1.5 h), this value had returned to its pre-ischemia (baseline) level, suggesting the LDH/PDH enzyme activity ratio may be used as a potential indicator for the status of the ischemic and recovering brain.

Experimental analysis of efficiency of electrochemical process of processing waste water for production of sodium bicarbonate with production of sodium hydroxiden

Experimental analysis of efficiency of electrochemical process of processing waste water for production of sodium bicarbonate with production of sodium hydroxiden

Imaging Acute Metabolic Changes in Patients with Mild Traumatic Brain Injury Using Hyperpolarized [1-13C]Pyruvate.

SummaryTraumatic brain injury (TBI) involves complex secondary injury processes following the primary injury. The secondary injury is often associated with rapid metabolic shifts and impaired brain function immediately after the initial tissue damage. Magnetic resonance spectroscopic imaging (MRSI) coupled with hyperpolarization of 13C-labeled substrates provides a unique opportunity to map the metabolic changes in the brain after traumatic injury in real-time without invasive procedures. In this report, we investigated two patients with acute mild TBI (Glasgow coma scale 15) but no anatomical brain injury or hemorrhage. Patients were imaged with hyperpolarized [1-13C]pyruvate MRSI 1 or 6 days after head trauma. Both patients showed significantly reduced bicarbonate (HCO3–) production, and one showed hyperintense lactate production at the injured sites. This study reports the feasibility of imaging altered metabolism using hyperpolarized pyruvate in patients with TBI, demonstrating the translatability and sensitivity of the technology to cerebral metabolic changes after mild TBI.

Abstract 12881: Noninvasive In Vivo Assessment of Cardiac Metabolism in Dobutamine-stressed Ischemic Rat Hearts Using Hyperpolarized 13 C MRI

Introduction and Hypothesis: Conventional metabolic imaging methods such as PET, dobutamine stress echo or late gadolinium enhancement do not directly detect the functional state of the critical organelle in oxidative metabolism, the mitochondrion. Hyperpolarized (HP) 13 C-metabolic imaging has been used to assess mitochondrial function in preclinical models and is an exciting new imaging method for evaluating the ischemic myocardium noninvasively. This study aims to evaluate myocardial response to dobutamine stress in ischemic rat hearts using HP-[1- 13 C]pyruvate. Methods: Metabolism of HP[1- 13 C]pyruvate was investigated in male SD rats in four groups: 1. normal myocardium (NM), 2. ischemic myocardium (IM), 3. NM+dobutamine, 4. IM+dobutamine. The myocardial ischemic model was developed by partial occlusion of the coronary artery as described in earlier studies by others. For dobutamine stress HP-MRS, intra-peritoneal injection of 1.5 mg/kg of dobutamine was administered before positioning the animal in the MRI scanner. 13 C data were acquired 7 days after the surgery in a 4.7 T MRI scanner using a Varian 60 mm dual-tuned 1 H/ 13 C linear volume coil. Anatomical 1 H images were acquired for slice planning and positioning. 13 C intensity maps were generated and displayed as overlays on grayscale 1 H images. In separate experiments, in vivo HP- 13 C-MRS data acquisition was initiated immediately after the pyruvate injection. Results: The HP signals from [1- 13 C]lactate, [1- 13 C]alanine, and 13 C-bicarbonate were detected in real-time 13 C spectra from hearts following injection of HP[1- 13 C]pyruvate. In hearts with partial coronary ligation, the MRS data were acquired from a mixture of ischemic and nonischemic myocardium. A 27% decrease in bicarbonate production was observed in hearts with ischemic myocardium compared to control hearts. After stimulation of NM hearts with dobutamine, less bicarbonate was produced from HP-pyruvate likely due to an increased contribution of other endogenous substrates to acetyl-CoA. Production of bicarbonate was unchanged in IM hearts following adrenergic stimulation. Conclusions: Our results demonstrated that decreased oxidative metabolism of pyruvate as a result of myocardial ischemia and dobutamine stress.

Ambient CO2/N2 Switchable Pickering Emulsion Emulsified by TETA-Functionalized Metal-Organic Frameworks.

In recent years, metal-organic frameworks (MOFs) have been explored as emulsifiers for the fabrication of Pickering emulsions and then used for hybrid material synthesis and interface catalysis. Nevertheless, stimuli-responsive Pickering emulsions stabilized by MOFs have been rarely reported so far, although they are of great importance for fundamental research studies and practical applications. Herein, for the first time, triethylenetetramine (TETA)-functionalized MOFs (ZIF-90/TETA) have been designed, synthesized, and used for fabricating CO2-/N2-response Pickering emulsions. It is shown that even at the ZIF-90/TETA content of 0.25 wt %, the functional MOF can still efficiently emulsify n-hexane and water to form a high internal phase Pickering emulsion. Importantly, the Pickering emulsion can be easily and reversibly switched between emulsification and demulsification by bubbling of CO2 and N2 alternatively at atmospheric pressure. The possible mechanism of the CO2/N2 switchable emulsion is investigated by zeta potential, water contact angle, interfacial tension, 13C NMR spectroscopy, and an optical microscope. It is found that the acid-base reaction of CO2 with TETA anchored on the surface of ZIF-90 leads to the production of hydrophilic ammonium bicarbonate and carbamate, which results in the emulsification of the Pickering emulsion. However, when N2 is bubbled to remove CO2, the reverse reaction takes place to cause the demulsification of the Pickering emulsion. Moreover, the CO2/N2 switchable Pickering emulsion has been successfully used as a microreactor for Knoevenagel reactions to demonstrate a highly efficient integration of chemical reaction, product separation, and ZIF-90/TETA recycling for a sustainable chemical process.

Effect of Doxorubicin on Myocardial Bicarbonate Production From Pyruvate Dehydrogenase in Women With Breast Cancer

Effect of Doxorubicin on Myocardial Bicarbonate Production From Pyruvate Dehydrogenase in Women With Breast Cancer