Concentrated Aqueous Solutions Research Articles

Mesoporous NaxMnOy-Supported Platinum–Cobalt Bimetallic Single-Atom Catalysts with Good Sulfur Dioxide Tolerance in Propane Oxidation

Manganese-based catalysts show a tremendous potential in propane oxidation due to their low cost and good catalytic activity but are easily deactivated by SO2. In this work, we first synthesized the mesoporous sodium-doped manganese oxide (meso-NaxMnOy) using the mesoporous silica (KIT-6) as a template after washing with a concentrated NaOH aqueous solution and then prepared the platinum–cobalt bimetallic single-atom (Pt1Co1/meso-NaxMnOy) catalyst using the polyvinyl pyrrolidone-protecting one-pot strategy. It was found that the doping of 13.8 wt % Na dramatically enhanced the SO2 tolerance of meso-NaxMnOy but inhibited its catalytic activity due to the alkali metal poisoning. Among all of the samples for the oxidation of propane, Pt1Co1/meso-NaxMnOy showed the highest catalytic activity (a propane conversion of 90% was obtained at 282 °C and a space velocity of 30 000 mL g–1 h–1, and apparent activation energy, specific reaction rate, and turnover frequency at 250 °C were 76.0 kJ mol–1, 78.9 × 10–5 mol gPt–1 h–1, and 193.7 × 10–3 s–1, respectively), which was associated with the Pt and Co double active sites with good dispersion, abundant electron deficiency, outstanding lattice oxygen mobility, good low-temperature reducibility, and large capacity and weak strength of propane adsorption. More importantly, the Pt1Co1/meso-NaxMnOy sample possessed the excellent resistance to sulfur dioxide. Propane oxidation occurred via different reaction routes over the MnO2, meso-NaxMnOy, and Pt1Co1/meso-NaxMnOy samples, with the Langmuir–Hinshelwood mechanism being dominated. Propane oxidation over Pt1Co1/meso-NaxMnOy might follow a pathway of propane → acetone and isopropoxide → carboxylate and fatty ether → CO2 and H2O. Pt and/or Co single atoms are highly dispersed on meso-NaxMnOy. SO2 is preferentially adsorbed at the Na site in Pt1Co1/meso-NaxMnOy, which protects the active Mn, Pt, and Co from being poisoned by SO2, hence making Pt1Co1/meso-NaxMnOy show good SO2 resistance in propane oxidation.

Controlling the Ion Transport Number in Solvent-in-Salt Solutions.

Solvent-in-salt (SIS) systems present promising materials for the next generation of energy storage applications. The ion dynamics is significantly different in these systems from that of ionic liquids and diluted salt solutions. In this study, we analyze the ion dynamics of two salts, Li-TFSI and Li-FSI, in highly concentrated aqueous and acetonitrile solutions. We performed high-frequency dielectric measurements covering the range of up to 50 GHz and molecular dynamics simulations. The analysis of the conductivity spectra provides the characteristic crossover time between individual charge rearrangements and the normal charge diffusion regime resulting in DC conductivity. Analysis revealed that the onset of normal charge diffusion occurs at the scale of ∼1.5-3.5 Å, comparable to the average distance between the ions. Based on the idea of momentum conservation, distinct ion correlations were estimated experimentally and computationally. The analysis revealed that cation-anion correlations can be suppressed by changing the solvent concentration in SIS systems, leading to an increase of the light ion (Li+ in our case) transport number. This discovery suggests a way for improving the light cation transport number in SIS systems by tuning the solvent concentration.

Regulating the Intermolecular Hydrogen Bond to Realize Directional Dimension Reduction of Lead Iodide Perovskite toward Low-Dimensional Photovoltaics.

A low-dimensional organic amine lead halide perovskite is an attractive semiconductor material that has potential application prospects in photovoltaics, light-emitting diodes, detectors, X-ray imaging, and other fields. It has been reported that the photoelectric properties of low-dimensional perovskite can be controlled by adjusting the chain length of organic ammonium, the ratio of precursor components, and van der Waals interaction between amine molecules. Herein, we report the successful synthesis of low-dimensional perovskite (PdEA)PbI4 (PdEA = piperidine ethylammonium) and (MlEA)PbI4 (MlEA = morpholine ethylammonium) single crystals by regulating the intermolecular hydrogen bond of organic ammonium ligands. The two-dimensional (2D) layered structure (PdEA)PbI4 single crystal with a fluorescence reflection peak at 563 nm was produced by the reaction of PdEA with PbO in a concentrated hydroiodic acid aqueous solution. Differently, the (MlEA)PbI4 single crystal prepared by replacing MlEA with PdEA presents a one-dimensional (1D) rod structure, and its fluorescence reflection peak is located at 531 nm. The optical bandgaps of (PdEA)PbI4 and (MlEA)PbI4 perovskite films were about 2.16 and 2.33 eV, respectively. Low-dimensional perovskite solar cells with 2D (PdEA)PbI4 and 1D (MlEA)PbI4 of perovskite films yielded efficiencies of 1.18 and 1.52%, respectively.

Physicochemical properties and detergency of special electrolytic-reduction ion water.

The detergency of special electrolytic-reduction ion water (S-100) was evaluated in comparison with typical synthetic surfactants. Furthermore, to examine the cleaning mechanism of S-100, various physicochemical characteristics of S-100 were measured and a comprehensive evaluation of cleaning was performed. S-100 (10%) had a detergency comparable to that of various surfactants, such as sodium dodecyl sulfate and sodium dodecyl benzene sulfonate, which are generally blended or mixed in residential detergents. In addition, concentrated aqueous solutions of 10% or more of S-100 showed stronger detergency. The cleaning mechanism of S-100 is mainly attributed to the effect of surface tension reduction due to dissolved hydrogen or hydrogen nanobubbles in S-100, and the alkalinity generated by electrolysis charged the surface of the dirt or adherend, resulting in a peeling effect.

Investigation of interfacial crystallization fouling behaviors and membrane re-functionalization based on a long-distance membrane distillation module

Membrane distillation technique can be applicable for the treatment of highly concentrated aqueous solutions. Crystallization and fouling on the membrane surface are important issues during a membrane distillation process, which significantly affect its separation performance. Crystallization precipitation is a gradual process along the normal direction of the membrane and the feed flow direction. It is not easy to observe the gradual behavior in a relatively small module with a short flow distance in common lab scale modules. In this work, a long-distance membrane distillation module (~2 m in length) was designed and set up to investigate the gradual evolutionary process of crystallization fouling on the porous membrane. A practical model was proposed to estimate the approximate position of crystallization fouling in a long-distance membrane distillation process based on multiple factors including operating parameters and intrinsic membrane properties. A set of proof-of-principle experiments were proceeded to observe and characterize the crystallization fouling behaviors on the membrane surface and inside the pores under various conditions. Furthermore, to re-functionalize the membrane distillation system with the membrane fully covered by salt crystals, flushing the system with pure water was applied. The performance of the re-functionalized system was also investigated.

Intercalation of 1,2,4-triazole in methanol modified-kaolinite: Application for copper corrosion inhibition in concentrated sodium chloride aqueous solution

New hybrid kaolinite was obtained for the first time by intercalation of 1,2,4-triazole (TAZ) in the interlayer space of methoxykaolinite. The successful synthesis of the material (K-TAZ) was fully confirmed by XRD, FTIR, and solid state 13C NMR spectroscopy characterizations. Thermogravimetric analysis of K-TAZ confirmed the quantitative intercalation of TAZ and allowed the determination of the chemical formula of the nanohybrid material (Si2Al2O5(OH)3,72(OCH3)0,28(TAZ)0,50(H2O)0,17(CH3CH2OH)0,06). The material was subsequently used as copper corrosion inhibitor in a concentrated NaCl aqueous solution (0.5 ​M), TAZ being well-known as copper corrosion inhibitor. K-TAZ behaves like a mixed inhibitor (cathodic and anodic) with an inhibition efficiency reaching 96.9% when an inhibitor concentration of 320 ​mg ​L−1 was used. The study of the role played by different constituents of K-TAZ on metal protection showed that the cathodic inhibition was mainly due to free methoxykaolinite particles while the de-intercalated TAZ molecules provides the anodic protection. Thermodynamic studies of the process revealed that K-TAZ protects the copper by reinforcing (through physical adsorption) the protective layer made of copper oxide and chlorides produced when the metal react with the corrosive sodium chloride solution. This work clearly demonstrates the potential use of kaolinite for the enhancement of the efficiency of some selected metal corrosion inhibitors.

Structure of corn bran hemicelluloses isolated with aqueous ethanol solutions and their potential to produce furfural

The alkali-soluble hemicelluloses extracted with 10% KOH solution from corn bran were further isolated with different concentrations of aqueous ethanol solutions. Herein 92.2% of the original hemicelluloses can be obtained and the cellulase enzymatic hydrolysis rate of the alkali treated corn bran can reach to 97.2%. The corn bran hemicelluloses were mainly glucuronoarabinoxylan, in which xylose (48.4–53.8%) and arabinose (27.8–33.2%) were the main components. More linear hemicelluloses with high molecular weight tended to be precipitated in low concentration aqueous ethanol solutions. Furthermore, the relationship between the structural features of these alkali-soluble corn bran hemicelluloses and their furfural yield was investigated in MIBK (methyl isobutyl ketone)/H2O biphasic system. Results showed that the hemicelluloses with high xylose content are benefit to the furfural production, and the highest furfural yield of 67.7% was obtained.

Solvability of the Non-Linearly Viscous Polymer Solutions Motion Model.

In this paper we consider the initial–boundary value problem describing the motion of weakly concentrated aqueous polymer solutions. The model involves the regularized Jaumann’s derivative in the rheological relation. Also this model is considered with non-linear viscosity. On the basis of the topological approximation approach to the study of hydrodynamics problems the existence of weak solutions is proved. Also we consider an optimal feedback control problem for this initial–boundary value problem. The existence of an optimal solution minimizing a given performance functional is proved.

Water‐Soluble Doubly‐Strapped Isolated Perylene Diimide Chromophore

Perylene diimides (PDIs), a well-studied class of organic dyes, have a strong tendency to self-aggregate in water, thus greatly restricting their phototheranostic applications. Herein, we report a water-soluble PDI cyclophane "Gemini Box" (GBox-14+ ), consisting of a central PDI chromophore enclosed by double-sided cationic molecular straps. Owing to the effective spatial isolation, the chromophore self-aggregation can be completely eliminated, even in a concentrated aqueous solution up to 2 mM. To our knowledge, GBox-14+ represents an interesting example of a fluorescent PDI cyclophane in water, capable of being employed for lysosome-targetable live-cell imaging. More importantly, the highly concentrated aqueous solution of PDI radical anion can be significantly stabilized by GBox-14+ to exhibit an excellent near-infrared photothermal effect, which was further exploited for efficient and selective antibacterial applications. This work provides a new access to water-soluble non-aggregated organic dyes and promotes their potential biomedical applications.

Water‐Soluble Doubly‐Strapped Isolated Perylene Diimide Chromophore

AbstractPerylene diimides (PDIs), a well‐studied class of organic dyes, have a strong tendency to self‐aggregate in water, thus greatly restricting their phototheranostic applications. Herein, we report a water‐soluble PDI cyclophane “Gemini Box” (GBox‐14+), consisting of a central PDI chromophore enclosed by double‐sided cationic molecular straps. Owing to the effective spatial isolation, the chromophore self‐aggregation can be completely eliminated, even in a concentrated aqueous solution up to 2 mM. To our knowledge,GBox‐14+represents an interesting example of a fluorescent PDI cyclophane in water, capable of being employed for lysosome‐targetable live‐cell imaging. More importantly, the highly concentrated aqueous solution of PDI radical anion can be significantly stabilized byGBox‐14+to exhibit an excellent near‐infrared photothermal effect, which was further exploited for efficient and selective antibacterial applications. This work provides a new access to water‐soluble non‐aggregated organic dyes and promotes their potential biomedical applications.

Separation of Pd(II) and Pt(IV) in concentrated hydrochloric acid using thin-layer oil membrane and comparison with conventional extraction

This study proposes a new thin-layer oil membrane (TOM) extraction strategy for enhanced mutual separation of Pd(II) and Pt(IV) chlorocomplex anions in concentrated aqueous hydrochloric acid solutions using di-n-butyl sulfoxide (DBSO) as an extractant. It was discovered that Pd(II) could be preferentially extracted even in concentrated hydrochloric acid solutions. The separation coefficient between Pd(II) and Pt(IV) considerably increased than that between them during conventional extraction using a separating funnel. A new extractor was designed to perform TOM extraction by spreading a thin layer of organic extractant liquid membrane on the surface of aqueous feed solutions under laminar flow. A simplified TOM extraction model and controlled experiments were used to investigate the effect of H+ and Cl− ion concentrations on the mutual separation between Pd(II) and Pt(IV). Molecular dynamics (MD) simulations were used to understand the microscopic separation mechanisms at the molecular level. Experimental results revealed that the competitive distribution of H+ and Cl− ions in the boundary layer along the normal vertical direction of the organic-aqueous interface are crucial in enhancing the separation between Pd(II) and Pt(IV). The competitive adsorption and enrichment of Cl− ions at the interface prevent DBSO molecules from being protonated by H+ ions, which is beneficial for the substituted coordination of DBSO molecules with PdCl42−. However, the ionic association of protonated DBSO molecules with PtCl62− remains dominant at the interface. As a result, even in concentrated hydrochloric acid solutions, the difference in mass transfer between PdCl42− and PtCl62− toward the interface was intensified.

Experimental verification of increased electronic excitation energy of water in hydrate-melt water by attenuated total reflection-far-ultraviolet spectroscopy.

The demand for Li secondary batteries is increasing, with the need for batteries with a higher level of performance and improved safety features. The use of a highly concentrated aqueous electrolyte solution is an effective way to increase the safety of batteries because it is possible to use "water-in-salt" (WIS) and "hydrate-melt" (HM) electrolytes for practical applications. These electrolytes exhibit a potential window of >3.0V, which is attributed to the difference between the HOMO and the LUMO energies of the n orbital of the pure water molecules and that of the water molecules in the hydration shells of a metal ion, according to theoretical predictions. Thus, in the present study, the attenuated total reflectance (ATR)-far-ultraviolet (FUV) spectra of water and super-concentrated aqueous solutions, such as WIS and HM using a Li salt, were experimentally investigated. The effects of anions, cations, and deuteriums on the ATR-FUV spectra were examined. The ATR-FUV method is an excellent means of studying highly concentrated aqueous salt solutions. The results suggest that the transition energy of water molecules in an ultrahighly concentrated aqueous electrolyte containing HM and WIS increased by nearly 0.4eV (corresponding to an energy shift of over 10nm) compared to an aqueous electrolyte with a typical water concentration. It was also revealed that the transition energy of water changes depending on the environment of the non-bonding electron, which is directly connected with or affected by hydrogen bonding with other water molecules or directly connected with Li+.

Electrolysis energy efficiency of highly concentrated FeCl2 solutions for power-to-solid energy storage technology

An electrochemical cycle for the grid energy storage in the redox potential of Fe involves the electrolysis of a highly concentrated aqueous FeCl2 solution yielding solid iron deposits. For the high overall energy efficiency of the cycle, it is crucial to maximize the energy efficiency of the electrolysis process. Here we present a study of the influence of electrolysis parameters on the energy efficiency of such electrolysis, performed in an industrial-type electrolyzer. We studied the conductivity of the FeCl2 solution as a function of concentration and temperature and correlated it with the electrolysis energy efficiency. The deviation from the correlation indicated an important contribution from the conductivity of the ion-exchange membrane. Another important studied parameter was the applied current density. We quantitatively showed how the contribution of the resistance polarization increases with the current density, causing a decrease in overall energy efficiency. The highest energy efficiency of 89 ± 3% was achieved using 2.5 mol L−1 FeCl2 solution at 70 °C and a current density of 0.1 kA m−2. In terms of the energy input per Fe mass, this means 1.88 Wh g−1. The limiting energy input per mass of the Fe deposit was found to be 1.76 Wh g−1.Graphical abstract

Electrochemical degradation of hydrolyzed polyacrylamide by a novel La-In co-doped PbO2 electrode: Electrode characterization, influencing factors and degradation pathway

• A novel La-In-PbO 2 co-doped electrode was prepared through electrodeposition. • The electrode presents compact pyramidal structure with large surface area. • The modification enhances the oxygen evolution potential and the stability of the electrode. • Hydrolyzed polyacrylamide can be degraded effectively. The anode materials play a key role in the electrochemical oxidation process. In this work, a new type of Ti/Sn-SbO x /α-PbO 2 /La-In-β-PbO 2 electrode has been prepared through electrodeposition and applied to the degradation of high concentration aqueous solution of hydrolyzed polyacrylamide (HPAM). Scanning electron microscopy (SEM), X-ray diffraction (XRD), and Energy-dispersive spectroscopy (EDS) were employed to characterize the surface morphological and structural properties of the electrodes, which indicated that the La-In-PbO 2 electrode had smaller grain size, denser surface and larger active surface area compared with undoped and single-doped PbO 2 electrode. Cyclic voltammetry (CV), linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS) were also utilized to investigate the electrochemical performance of electrodes. The results showed that the La-In-PbO 2 electrode exhibited higher oxidation peak current, oxygen evolution potential (2.22 V) and lower charge transfer resistance. The La-In-PbO 2 electrodes were used as anode to degrade HPAM solution under different conditions. The results revealed that the viscosity reduction rate of HPAM reached to 97.63 % after 60 min under the condition of electrolyte concentration, initial concentration of HPAM, initial pH and current density were 0.05 M, 3 g·L −1 , 7 and 20 mA·cm −2 , respectively. The kinetic behavior of HPAM degradation was analyzed by the viscosity reduction experiment. The intermediates in the electrochemical oxidation process were identified by GC–MS and the possible degradation mechanism of HPAM was explored by UV–visible absorption spectra and the Fourier Transform Infrared (FT-IR) spectra.

Aluminum-copper alloy anode materials for high-energy aqueous aluminum batteries

Aqueous aluminum batteries are promising post-lithium battery technologies for large-scale energy storage applications because of the raw materials abundance, low costs, safety and high theoretical capacity. However, their development is hindered by the unsatisfactory electrochemical behaviour of the Al metal electrode due to the presence of an oxide layer and hydrogen side reaction. To circumvent these issues, we report aluminum-copper alloy lamellar heterostructures as anode active materials. These alloys improve the Al-ion electrochemical reversibility (e.g., achieving dendrite-free Al deposition during stripping/plating cycles) by using periodic galvanic couplings of alternating anodic α-aluminum and cathodic intermetallic Al2Cu nanometric lamellas. In symmetric cell configuration with a low oxygen concentration (i.e., 0.13 mg L−1) aqueous electrolyte solution, the lamella-nanostructured eutectic Al82Cu18 alloy electrode allows Al stripping/plating for 2000 h with an overpotential lower than ±53 mV. When the Al82Cu18 anode is tested in combination with an AlxMnO2 cathode material, the aqueous full cell delivers specific energy of ~670 Wh kg−1 at 100 mA g−1 and an initial discharge capacity of ~400 mAh g−1 at 500 mA g−1 with a capacity retention of 83% after 400 cycles.

On-line ascertain the processing fluidity of concentrated poly(vinyl alcohol) aqueous solutions

Understanding the viscous fluid behavior of concentrated aqueous solution of poly (vinyl alcohol) (PVA), wherein macromolecular coils severely overlap and/or entangle each other, is of significance to the process design of PVA solution fabrication. However, exploiting the fluidity of PVA solutions under severe conditions of simultaneously high operational temperature (Top), high concentration (CPVA) and large polymerization degree (PD) has been less involved in the past studies irrespective of practical importance. Herein, we utilize a self-made hydrothermal kettle with a built-in online viscometer to systematically trace the changes of apparent viscosity (ηap) of PVA aqueous solutions arising from the variables of Top (up to 160 °C), CPVA (high as 28%) and PD (largest at 3000). Applying Andrade's equation, the activation free energy of viscous flow (Eη) is deduced from ln ηap ∝ 1/Top. It shows that all the values of Eη approximate to 37 (±3) kJ·mol−1 although both CPVA and PD increased progressively, indicating that these two factors will not affect the Top sensitivity of ηap. Meanwhile, the contour plots of ηap in CPVA-Top space are established for various PVAs with different PDs, to manifest the development trend of fluidity upon multiple external-fields coupling. Clarifying the synergic effect of CPVA-Top-PD on ηap may offer guidance for the preparation of PVA films by determing appropriate solution processing variables. The results of our study are of help to the PVA fabrications such as spinning fiber and casting film, in which precise control of flowability of concentrated solution is crucial.

Manufacturing of macroporous cellulose monolith from green macroalgae and its application for wastewater treatment

Enormous interest in using marine biomass as a sustainable resource for water treatment has been manifested over the past few decades. Herein, the objective was to investigate the possible use of green macroalgae (Codium tomentosum) for cellulose-based foam production through a versatile and convenient process. Macroporous cellulose monolith was prepared from cellulose hydrogel using freeze-drying process, resulting in a mechanically rigid monolith with a high swelling ratio. The as-produced spongy-like porous cellulosic material was used as bio-sorbent for wastewater treatment, particularly for removing methylene blue (MB) dye from concentrated aqueous solution. The adsorption capacity of MB was subsequently studied, and the effect of adsorption process parameters was determined in a controlled batch system. From the kinetic studies, it was found that the adsorption equilibrium was reached within 660 min. Furthermore, the analysis of the adsorption kinetics reveals that the data could be fitted by a pseudo-second order model, while the adsorption isotherm could be described by Langmuir isotherm model. The maximum adsorption capacity was found to be 454 mg/g. The findings suggested that the produced cellulose monolith could be used as a sustainable adsorbent for water treatment.

Stability of a high-concentrated aqueous solution of idarubicin stored in a polypropylene syringe for transarterial chemoembolization

Idarubicin (IDA) is an antineoplasic drug commonly used to treat hematologic diseases. Because of its relative lipophilic properties, this anthracycline is also used in transarterial chemoembolization (TACE) as part of hepatocellular carcinoma (HCC) treatment. But TACE requires injected volume to be reduced to restrict systemic diffusion and side effects. The aim of this study was to determine the stability of a highly concentrated aqueous solution of IDA, stored in polypropylene syringes between 2 °C and 8 °C. Analyses were performed with an HPLC system combined with UV detector and mass spectrometer. Forced degradation was used to investigate potential degradation products. This study demonstrated 7 days of stability after storage in previously mentioned conditions. This conservation is long enough to anticipate drug preparation and facilitates pharmacy organization.

Self‐Assembly of All‐DNA Rods with Controlled Patchiness

AbstractDouble‐stranded DNA (dsDNA) fragments exhibit noncovalent attractive interactions between their tips. It is still unclear how DNA liquid crystal self‐assembly is affected by such blunt‐end attractions. It is demonstrated that stiff dsDNA fragments with moderate aspect ratio can specifically self‐assemble in concentrated aqueous solutions into different types of smectic mesophases on the basis of selectively screening of blunt‐end DNA stacking interactions. To this end, this type of attractions are engineered at the molecular level by constructing DNA duplexes where the attractions between one or both ends are screened by short hairpin caps. All‐DNA bilayer and monolayer smectic‐A type of phases, as well as a columnar phase, can be stabilized by controlling attractions strength. The results imply that the so far elusive smectic‐A in DNA rod‐like liquid crystals is a thermodynamically stable phase. The existence of the bilayer smectic phase is confirmed by Monte‐Carlo simulations of hard cylinders decorated with one attractive terminal site. This work demonstrates that DNA blunt‐ends behave as well‐defined monovalent attractive patches whose strength and position can be potentially precisely tuned, highlighting unique opportunities concerning the stabilization of nonconventional DNA‐based lyotropic liquid crystal phases assembled by all‐DNA patchy particles with arbitrary geometry and composition.

Preparative Biocatalytic Synthesis of α-Ketoglutaramate.

α-Ketoglutaramate (KGM) is an underexamined metabolite of L-glutamine in the metabolic pathway of glutaminase II of α-ketoglutarate formation. Presumably, KGM may be a biomarker of hepatic encephalopathy and other hyperammonemic diseases. This metabolite is a substrate for the ω-amidase enzyme and is used to determine its activity in the study of the biochemistry of various types of cancer. However, the commercial unavailability of KGM hinders its widespread use. Methods for the preparative synthesis of KGM are known, but they either do not provide the proper yield or proper purity of the target product. In this work, a detailed description of the procedures is given that allows the production of KGM with a purity above 97% and a yield of the target product above 75% using L-amino acid oxidase from C. adamanteus as a catalyst of L-glutamine conversion. KGM can be obtained both in the form of a highly concentrated aqueous solution and in the form of crystals of sodium salt. The developed methods can be used both for scaling up the synthesis of KGM and for creating economical biocatalytic technologies for the production of other highly purified preparations.