Use of sodium carbonate and sodium polyacrylate for the prevention of vinegar syndrome

To preserve archive films of which the base material is composed of cellulose acetate, we carried out screening tests on various reagents. We selected sodium carbonate and sodium polyacrylate as an acetic acid gas removing agent and a dehumidification agent, respectively. The performance of sodium carbonate per unit mass in the removal of acetic acid gas was superior to those of commercial products. The presence of sodium carbonate suppressed the increase in concentration of acetic acid gas for several months in film preservation containers. The neutralization of sodium carbonate with acetic acid gas was evaluated quantitatively. Sodium polyacrylate controlled relative humidity at around 40%RH in film preservation containers, and it was effective for film preservation. The dehumidifying performance of sodium polyacrylate compared favourably with those of commercial products. Thus, the materials tested in this study are found to be useful to avoid vinegar syndrome in cellulose acetate-based films.     

A preliminary study on intravenous infusion of sodium eicosapentaenoate

Eicosapentaenoic acid (EPA) and arachidonic acid (AA), made into sodium salt solution (50 μg/ml), were used for intravenous infusion. In a preclinical study in dogs, Na-EPA lowered the activity of transminases (glutamic pyruvic transaminase [GPT], glytamic oxaloacetic transaminase [GOT]); however, Na-AA increased the activity of GPT and GOT. In the clinical study, the numbers of leukocytes and lymphocytes of volunteers increased and remained at that level for 3 to 5 days after intravenous infusion. The study indicated that an intravenous infusion of Na-EPA may have anti-inflammatory and immunomodulatory effects.     

Preparation of polyaniline nanostructures using sodium dodecylsulphate

Polyaniline (PANI) nanostructures with an average diameter of 30-35 nm and a conductivity of 2.13-1.15 × 10^− 1 S/cm were prepared using sodium dodecylsulfate (SDS) emulsion in the absence of any added acid. Fiber like nanostructures was observed after 1 and 2 h, whereas an aggregated particulate morphology was observed for 4 and 24 h. The effect of the reaction time on the PANI morphology was monitored using field-emission scanning electron microscopy (FESEM). Furthermore, the effects of the reaction time on the chemical structure, conductivity and crystallinity of PANI are reported.     

Adsorption reactions of carboxylic acid functional groups on sodium aluminoborosilicate glass fiber surfaces

Multicomponent silicate glasses are ubiquitous in modern society as evidenced by their inclusion in applications ranging from building materials and microelectronics to biomedical implants. Of particular interest in this study is the interface between multicomponent silicate glasses and adhesive polymers. These polymeric systems often possess a variety of different organic functional groups. In this study, we selected acetic acid as a probe molecule representative of the carboxylic acid functional group found in many adhesives. We have used Fourier transform infrared spectroscopy (FT-IR) and NMR to study the interaction of acetic acid with the surface of sodium aluminoborosilicate continuous glass fibers. Methods were developed that enable analyses to be carried out without damaging or altering the pristine as drawn fiber surface. While dosing the surface of fumed silica with acetic acid resulted in the formation of silyl ester groups, analogous dosing of sodium aluminoborosilicate glass fibers resulted in the formation of carboxylate species, principally coordinated to sodium, while silyl ester groups were not observed.     

坡缕石/聚丙烯酸(钠)高吸水复合材料的溶胀行为

以水溶液聚合法制备了坡缕石/聚丙烯酸(钠) (PAANa)高吸水复合材料,对复合材料的吸水溶胀性能进行了研究,并采用FTIR对复合材料进行表征。结果表明：10 %坡缕石/PAANa复合材料吸蒸馏水和0.9 wt%盐水倍率分别达1666g/g、115g/g,较纯PAANa的724g/g、58g/g明显提高;坡缕石/PAANa复合材料具有优异的保水及反复吸水性能;坡缕石/PAANa的吸液倍率随电解质溶液离子强度的升高而降低,降低程度顺序为 Al3+>Ca2+>Na+;坡缕石/PAANa复合材料与其他6种矿物/PAANa复合材料相比,吸液性能特别是吸蒸馏水及0. 9 wt%盐水性能大幅提高。     

Osteogenic effect of hyaluronic acid sodium salt in the pores of a hydroxyapatite scaffold

According to previous reports, a large volume of bone marrow cells (1 × 10⁷ cells/ml) is required for bone regeneration in the pores of a scaffold in vivo. We theorized that immersion of a porous hydroxyapatite (HA) scaffold in hyaluronic acid solution would facilitate bone formation in the scaffold at 1 × 10⁶ cells/ml density of bone marrow cells. The cells were respectively seeded into pores of the cylindrical HA scaffolds with a hollow center after immersion in hyaluronic acid solution or in culture medium. The scaffolds were implanted in the dorsal subcutis of rats for 4 weeks. Thereafter, serially sectioned paraffin specimens were made and observed histologically. Bone formation was observed in many pores of HA scaffold by immersion in hyaluronic acid solution. However, there were no or less pores with new bone formation in the scaffold by immersion in culture medium. The cells were cultured with and without hyaluronic acid in vitro. There was no significant difference in bone formation in vitro with and without hyaluronic acid. The results of this study suggest that hyaluronic acid binds to the cells on the wall of three-dimensional structure and effectively promotes new bone formation.     

Kinetics and mechanism of chloride based chlorine dioxide generation process from acidic sodium chlorate

The reaction between sodium chlorate and sodium chloride in presence of aqueous sulfuric acid is studied in a well stirred reactor at various temperatures and molar concentrations of chlorate, chloride and acid. The reaction rate is evaluated by analyzing the consumption of chlorate or chloride iodometrically or argentometrically. The rate law is established. Reaction has been found first and second order with respect to chlorate and chloride concentration, respectively. Reaction order is found about 13-14 with respect to molar concentration of sulfuric acid but it reduced to 2.4 when acidity function, h_, is substituted in place of molar concentration. The temperature dependence of the reaction is also investigated and pre-exponential Arrhenius parameter as well as activation energy are determined. It has been observed that ClO(2)/Cl(2) ratio is markedly affected by chlorate to chloride ratio. Reaction mechanism compatible with the reaction kinetics is proposed.     

Electrospun multifunctional diclofenac sodium releasing nanoscaffold

Electrospinning is a method utilized to produce nano-scale fibers for tissue engineering applications. A variety of cells are attracted by nano scale surfaces and structures probably due to the similarity of their natural environment scale. In this study, diclofenac sodium (DS) releasing nanofibers were manufactured via electrospinning process. Poly(95 epsilon-capro/5 D,L-lactide) was dissolved into acetic acid to form a 20% w/v solution. 2% w/w of DS was then added into the polymer solution and stirred homogenously. About 1 g of polymer/drug solution was spun onto the collector under electrostatic conditions. The distance between needle tip and sample collector was arranged to 10 cm and applied electric field was 2 kV/cm. Release rate of DS was measured by using UV/VIS spectrophotometer. Resulted highly porous nanofiber scaffold was about 2 mm thick and the diameter of nanofibers was approximately 130 nm. Structure included in also spheres with approximately diameter of 3.30 microm. About 45% of DS was released during the first 24 hours and after that the release decreased to almost zero value. After 35 days release rate increased. This study revealed that manufacturing of highly porous DS releasing nanoscaffold by electrospinning process is feasible. Having fast DS release rate nanofibrous scaffold made of poly(95 epsilon-capro/5 D,L-lactide) can be of benefit for applications where immediate control of tissue reaction is needed.     

Development of diclofenac sodium releasing bio-erodible polymeric nanomats

Application of nanofiber-based nanomats in medicine is attractive and thanks to the 3D nanostructure and the high surface to volume ratio they are excellent for local controlled drug delivery. The use of bioactive bioerodible polymers for developing drug delivery nanomats may allow for drug release and targeting control. Objective of the current study was to evaluate the suitability of bioerodible polymeric material based on n-butyl hemiester of [poly(maleic anhydride-alt-2-methoxyethyl vinyl ether)] (PAM14) for the preparation of nanomats for controlled administration of anti-inflammatory, diclofenac sodium (DS) drug. Samples were prepared using different polymer concentrations (5-10%) in either ethanol or acetic acid as solvent. Morphology was investigated by using scanning electron microscopy (SEM). Thermal analysis such as differential scanning calorimetry (DSC) was performed to detect effect on polymer arrangement. DS localization in electrospun nanomats was evaluated by using electron back scattering microanalysis, based on the detection of chlorine, and drug release kinetics was assessed using UV-Vis. Average fiber diameter resulted in the range of 100 nm to 1.0 microm and a homogeneous distribution of the loaded drug into the fibers was observed. The DS release was immediate and despite the preliminary nature of the performed electrospinning experiments, the achieved results appear promising for the future development of a novel system for the controlled and targeted administration of drug and active agent.     

The removal of nitrate by nanoscale iron particles produced using the sodium borohydride method

This study was conducted to investigate removal of nitrate by nanoscale zero-valent iron (ZVI) particles in aqueous solution. ZVI particles was produced from wasted acid that is by-products of a pickling line at a steel work. The reaction activity of ZVI particles was evaluated through decomposition experiments of NO3-N aqueous solution. Addition of a larger amount of ZVI particles resulted in a higher decomposition rate. ZVI particles showed higher decomposition efficiencies than commercially purchased ZVI particles at all pH values. Both ZVIs showed a higher decomposition rate at a lower pH. Virtually no decomposition reaction was observed at pH of 4 or higher for purchased ZVI. The ZVI particles produced directly from wasted acid by the sodium borohydride method were not easy to handle because they were very small (10-200 nm) and were oxidized easily in the air.     

Combustion synthesis of tungsten powder from sodium tungstate

Tungsten powders were prepared by Self-propagating High-temperature Synthesis (SHS) method directly from hitherto unreported system: sodium tungstate (Na₂WO₄) and magnesium (Mg). The adiabatic temperatures of self-propagating combustion reactions with different amount of Mg in Na₂WO₄ + Mg system were calculated. The influences of different starting conditions (molar ratios of Mg/Na₂WO₄ and relative densities of samples) on the compositions and microstructure of reaction products were investigated. It shown that, the complete reduction of WO₃ required a 60% excess of magnesium over the stoichiometric molar ratio Mg/Na₂WO₄ of 3. The amount of the impurities is minimal at appropriate relative density. At last, tungsten powders can be obtained after the acid enrichment and distilled water washing.     

Effect of ethylenediaminetetraacetic acid (di sodium salt) and aquasoft 330 on crystal growth and morphology of calcium oxalate

Calcium oxalate was synthesized from calcium chloride solution using oxalic acid in the presence of di sodium salt of ethylenediaminetetraacetic acid (EDTA) and commercially available1-hydroxyethylidene-1,1-diphosphonic acid (HEDP), aquasoft having chelating value 330 (AQ 330). The experiments were carried out at three different temperatures 60, 80 and 100 °C. The samples were characterized using scanning electron microscope (SEM), powder X-ray diffraction analysis (XRD) and Fourier transform infrared spectroscopy (FTIR) techniques. The morphological studies reveal that the tendency for agglomeration increases with increase in temperature. Interpretation of XRD pattern confirmed that whewellite with monoclinic structured is the most favored structure in the presence of EDTA where calcium oxalate hydrate having orthorhombic structure is most favored structure in the presence of AQ 330.     

基于PCB的次磷酸钠化学镀铜研究

为解决传统甲醛化学镀铜体系环境污染及稳定性低的问题,以次磷酸钠化学镀铜体系为研究对象,采用SEM、XRD、电化学等测试方法,探讨了添加剂硫酸镍、α-α’联吡啶和马来酸对该体系的影响.结果表明:适量的硫酸镍和马来酸均能提高化学镀速并改善镀层外观质量,其适宜的质量浓度分别为0.8 g/L和10 mg/L;α–α’联吡啶能明显改善镀层外观质量,其适宜的质量浓度为10 mg/L;次磷酸钠体系的镀液稳定性能优越,加入混合添加剂在80℃下稳定时间近48 h;混合添加剂使化学镀铜阴极峰电流增大;在最佳工艺条件下镀速为5.10μm/h,获得的镀层均匀、致密,施镀20 min后背光级数达到10级.     

双极性膜电渗析法转化对甲基苯磺酸钠盐的工艺条件研究

通过双极性膜电渗析法,把d-对羟基苯甘氨酸生产中产生的对甲基苯磺酸钠盐转化为对甲基苯磺酸和氢氧化钠．实验对比了两室双极性膜电渗析和三室双极性膜电渗析工艺的优劣．根据比较,确定了处理实际料液时的最佳转化条件为：将两室法转化和对羟基苯甘氨酸(p-HPG)的溶解过程耦合进行．并在此基础上,提出了改进d-对羟基苯甘氨酸生产工艺的方法。     

Resistance of different types of concretes to cyclic sulfuric acid and sodium sulfate attack

An improvement in accelerated testing as a way of predicting durability was proposed in this study. Accordingly, the behavior of different concrete mixtures was examined in relation to a cyclic exposure to sulfuric acid and sodium sulfate solutions, recording the expansion and mass loss of the test specimens for about 5 years. Three different cements – i.e. Portland limestone, blast furnace slag and pozzolanic cement – were used, the latter two both with and without silica fume (SF), to prepare the concretes for the study. Scanning Electron Microscopy (SEM) and energy-dispersive X-ray analysis (EDX) were used to correlate the samples’ microstructure and deformation.The lowest expansion was obtained by mixtures containing silica fume, although they were more susceptible to corrosion in acid. After a dormant period when no expansion occurred, the Portland limestone cement and blast furnace slag cement exhibited a large expansion that began suddenly and increased at an almost constant rate. This expansion correlated with the presence of cracks filled with calcium sulfate crystals in the core of the concrete samples.For comparison, the expansion of concretes specimens left in a sodium sulfate solution was also measured. The dormant period in the two-step expansion process seen in the Portland limestone and blast furnace concretes was shorter in the cyclic testing in sulfate and sulfuric acid, which can be considered as a model of accelerated deterioration, than in the latter.     

Synthesis and electrochemical probing of water-soluble poly(sodium 4-styrenesulfonate-co-acrylic acid)-grafted multiwalled carbon nanotubes

Water-soluble poly(sodium 4-styrenesulfonate-co-acrylic acid)-grafted multiwalled carbon nanotubes (MWNT-g-P(SSS-co-AA)) with core-shell nanostructure were successfully synthesized by in situ free radical copolymerization of sodium 4-strenesulfonate (SSS) and acrylic acid (AA) in the presence of MWNTs terminated with vinyl groups; their structure was characterized by FTIR, (1)H NMR, Raman, TGA and TEM. The results showed that the thickness and content of the copolymer layer grafted onto the MWNT surface are about 7-12?nm and 82.3%, respectively. The P(SSS-co-AA) covalently grafted on MWNTs provides MWNT-g-P(SSS-co-AA) with good hydrophilicity and solubility in water. Then a novel MWNT-g-P(SSS-co-AA)-modified glassy carbon electrode was fabricated by coating; its electrochemical properties were evaluated by electrochemical probe of K(3)[Fe(CN)(6)], and its catalytic behaviors to the electrochemical oxidation processes of dopamine (DA) and serotonin (5-HT) were investigated. Since the MWNT-g-P(SSS-co-AA)-modified electrode possesses strong electron transfer capability, high electrochemical activity and catalytic ability, it can be used in sensitive, selective, rapid and simultaneous monitoring of biomolecules.     

Fast ionic conduction in sodium phosphate-borate compositions

Equimolar mixtures of sodium orthophosphate and sodium diphosphate with boric acid heated to 800 – 1000°C form glasses. The glasses exhibit high ionic conductivities for sodium ions. Dense polycrystalline samples of the same materials show higher conductivities than the glassy samples.     

Rapid liquid chromatographic determination of paracetamol and diclofenac sodium from a combined pharmaceutical dosage

A simple, rapid reversed-phase HPLC method for the estimation of paracetamol and diclofenac sodium simultaneously in a combined dosage was developed. A -CN bonded phase columb was used with a mobile phase methanol-potassium dihydrogen phosphate (0.05M), (45:55) pH 3.5 adjusted with phosphoric acid at flow rate of 1.0 ml/min. For accurate quanittaiton, diltiazem hydrochloride was used as an internal standard at 270 nm.     

Influence of admixed citric acid and physiological variables on the vinpocetine release from sodium alginate compressed matrix tablets

In this study, the controlled release matrix tablets of vinpocetine were prepared by direct compression using sodium alginate (SAL) as hydrophilic polymer and different amounts of citric acid as hydrosoluble acidic excipient to set up a system bringing about zero-order release of this drug in distilled water containing 0.5% sodium dodecyl sulfate. At the critical content of admixed citric acid (60 mg/tab.), the lowest drug-release rate was observed. In order to explain the effect of this critical content on drug-release rate from SAL matrices, investigation of the possibility of interaction of citric acid with SAL was performed using differential scanning calorimetric analysis and infrared analysis, which confirmed the existence of direct citric acid-SAL interaction when these two excipients came in contact with water. A zero-order drug-release system could be obtained by regulating the ratio of citric acid-to-SAL and the capacity of this system in controlling drug-release rate depended on the extent of interaction between citric acid and SAL. It is worth noticing that pH and the ionic strength of the dissolution medium were found to exert an influence on the drug-release performance of SAL tablets.     

PAA-Na/PVA半互穿网络水凝胶的离子强度及pH敏感性

采用水溶液聚合法制备了聚丙烯酸钠(PAA-Na)/聚乙烯醇(PVA)半互穿网络水凝胶,研究了水凝胶在不同pH溶液、不同浓度NaCl与CaCl2溶液中的溶胀行为,结果表明,溶胀比随丙烯酸含量增大而增加,在碱性溶液中的溶胀度明显高于酸性溶液,溶胀平衡凝胶在酸性及碱性条件下均出现收缩,在pH=2和pH=12溶液中反复交换时,表现出可逆溶胀-退溶胀性能,具有较好的pH敏感性,凝胶在不同浓度NaCl与CaCl2溶液中溶胀性表明,溶液的离子强度及阳离子的电荷数对凝胶溶胀行为有较大影响。