Influence Of Organic Additives Research Articles

Specific Morphological Features of the Surface of Chromium Coatings Obtained in Electrolytes with Organic Additives

At the present time, the electrodeposition of chromium metal coatings of sufficient thickness and quality is possible only from chromium plating electrolytes containing chromic acid. The authors investigated the effect of the composition of chromium plating electrolyte on the quality of the resulting metal coating. It has been demonstrated that the introduction of organic additives, of gallic acid in particular, leads to significant changes in the surface of the metal deposit and to a decrease in its hardness. Assumptions have been made about the influence of organic additives on the metal deposition process. The experimental data on the content of gases in the chromium deposits obtained from electrolytes with gallic acid additive and without it have been presented.

Influences of Organic Additives on Asymbiotic Seed Germination of Dendrobium cruentum Rchb. f. for In Vitro Micropropagation

Dendrobium cruentum Rchb. f., a commercial orchid in Thailand, faces the risk of extinction and should be conserved, and propagated for commercial. Therefore, the aim of this research was to identify a suitable VW medium supplemented with organic additives for the micropropagation of D. cruentum through asymbiotic seed germination. The VW media supplemented with separate organic additives (coconut water (CW) (100 mL/L), ‘Hom Thong’ banana homogenate (BH) (1000 mg/L), and potato homogenate (PH) (1000 mg/L) or its combination was determined, and the seed germination rate (%), protocorm formation, and plantlet development were observed. The results showed that a combination of BH and PH resulted in the highest seed germination (94.69 ± 1.55 %) when compared to basal VW (control). Protocorm formation was highest with CW alone (47.38 ± 7.17 %) and a combination of CW and PH (52.13 ± 6.20 %). Additionally, after 10 weeks of culture, supplementation with BH yielded the highest number of plantlets. However, after 24 weeks of culture, each organic additives gave the different developments of healthy plantlets. To investigate suitable potting media for acclimatization of well-grown plantlets in greenhouse conditions, 2 pieces of foam, dried coconut husk, and a combination of peat moss: Sphagnum moss: Pumice: Perlite (3:1:1:1) were investigated. The highest survival rate percentage was found in foam-planted plantlets (80 %). Ultimately, the effectively simple mediums containing organic additives and a one-step protocol were provided for the micropropagation of D. cruentum via seeds, and the derived information could be used for D. cruentum conservation and production. HIGHLIGHTS The effects of organic additives on asymbiotic seed germination for in vitro micropropagation of Dendrobium cruentum Rchb. f. was firstly reported The media supplemented with organic additives yield significantly the highest seed germination, protocorm formation, and plantlet formation and development of D. cruentum when compared to basal media In greenhouse conditions, 2 pieces of foam gave the highest survival rate percentage of plantlets (80 %) The practical and beneficial media supplemented with organic additives for micropropagation of D. cruentum was provided GRAPHICAL ABSTRACT

Influence of organic additives with electron‐withdrawing and electron‐donating groups on insulation properties of cross‐linked polyethylene at high temperatures for HVDC cable applications

AbstractThis paper investigated the influence of three aromatic voltage stabilizers (4‐n‐propylbenzoic acid, 2‐methoxyphenylboronic acid, and 3‐aminobenzoylmethylamide) on insulating properties of cross‐linked polyethylene (XLPE) at high temperatures for high voltage direct current (HVDC) applications. The XLPE blends containing 1 wt% voltage stabilizers were prepared through a solution‐blending method. The addition of voltage stabilizers suppressed the space charge inside the XLPE at high temperatures. The DC conductivity of XLPE and its blends increased with temperature. The DC conductivity of the XLPE blended with the 4‐n‐propylbenzoic acid was lowest at the different temperatures and electric fields. The DC breakdown strength of the tested materials continually decreased as the temperature increased. Notably, the DC breakdown strength of XLPE with the addition of 4‐n‐propylbenzoic acid and 3‐aminobenzoylmethylamide was higher than the reference XLPE at high temperatures. Moreover, the thermal stability of the XLPE remained unaffected after the voltage stabilizer's addition, whereas the thermal conductivity was improved. Quantum chemical calculations showed that the addition of voltage stabilizers with lower LUMO could effectively buffer the high‐energy electrons and improve the DC breakdown strength of the XLPE. A buffering mechanism of high‐energy electrons demonstrated the effect of the voltage stabilizers on the DC breakdown strength in the XLPE.

ПЕРСПЕКТИВЫ ИСПОЛЬЗОВАНИЯ ТРИХЛОРЭТИЛАМИДОВ С ТИОАМИДНЫМИ ФУНКЦИЯМИ В ТЕХНОЛОГИИ БЛЕСТЯЩЕГО НИКЕЛИРОВАНИЯ

The influence of organic additives in the nickel-plating sulfate electrolyte on the pos sibility of obtaining shiny coatings is investigated. The presence in the structure of the additive of 
 trichloramide fragments and substituents containing a thiocarbonyl group-a residue of thiourea or 
 rubeanoic acid, allows to obtain shiny nickel coatings without the introduction of additional reagents.

Influence of the amphiphilic molecule on high-density polyethylene crystallization

The influence of organic additives on crystallization of polyolefins has not been paid enough attention due to the low dosage, but it may have a significant impact on the properties of polyolefins. In the paper, the organic amphiphilic molecules were introduced into high-density polyethylene (HDPE) through melt blending, and compared with neat HDPE. It is mainly discussed for the following aspects including analysis of crystal structure and morphology using wide-angle X-ray diffraction (WAXD) and polarized optical microscopy (POM), respectively; analysis of crystallinity, crystal rate, crystal growth and crystallization enthalpy, using the differential scanning calorimetry (DSC). The research indicates that the organic amphiphilic molecules may act as an internal lubricant. On the one hand, HDPE molecular chains are easy to fall off from crystal lattices, resulting in lagging crystallization peak, simultaneously reducing the interaction between HDPE molecules should induce the lower activation energy (ΔEm) to increase the crystallinity of HDPE. On the other hand, the amphiphilic molecules should be exclude from HDPE crystal to the amorphous area due to poor compatibility; thus, the HDPE/amphiphilic molecules blends, similar to neat HDPE, conduct homogeneous nucleation, and the growth of monocrystal performs the tendency of the zero-dimension to the two-dimension with increase in temperature of isothermal crystallization and decreasing cooling rate of non-isothermal crystallization. It is hoped that through these studies, people will pay more attention to the impact of organic additives on the performance of HDPE.

ТЕОРЕТИЧЕСКИЕ ОСНОВЫ ПОИСКА НОВЫХ ДОБАВОК, СНИЖАЮЩИХ УСАДКУ ЦЕМЕНТНЫХ СИСТЕМ

A hypothesis about the mechanism of reducing shrinkage deformations under the influence of organic additives is presented. It may become the basis for the search for new additives that reduce the cement stone shrinkage by preventing the convergence of parallel surfaces of new formations due to electrosurface interactions with the functional group of the additive. The results of the study of the shrinkage of foam concrete with the addition of citric and sulfanilic acids are presented. It was found that they reduce shrinkage deformations by up to 76% with follow-up periods of up to 60 days. The proposed scheme of the action of additives on shrinkage allows us to conduct a directed search for surfactants that reduce the shrinkage deformations of foam cement stone

Influence of organic additives on electret state of high pressure polyethylene

The paper presents the results of a study of the electret properties of high-pressure polyethylene (hppe) modified with organic additives as phthalic-anhydride (pha) and orthophenylenediamine (ophd). Samples obtained and processed by extrusion on an industrial unit brand LRP-700m. Additives were introduced into HPPE by mechanical mixing. For polarization, the samples were placed on a grounded electrode and charged with a negative corona at a voltage of 7 kv. After polarization, the total surface charge of the samples was determined by the compensation method. The thermally stimulated current was recorded in the temperature range 290–520 K, provided that the heating increased linearly at a rate of 3.5 k / min. It is shown that after polarization of hppe composites modified with pha and ophd organic fillers, the depolarization process begins in connection with the resolution and release of trapped charge carriers from traps. After the complete destruction of the homo charges, the density of the surface charge of the hppe films and their optimal modification, reaching a certain value, in the future, depending on the duration of storage, does not change. It was also revealed that the introduction of the organic additive pha and ophd into hppe makes it possible to obtain an antistatic polymer material with improved technological and electrical properties.

Impact of organic additives on synthesis and upconversion luminescence properties in Ln3+, Yb3+ (Ln3+=Er3+/Tm3+/Ho3+) doped CaSc2O4 nanocrystals via hydrothermal method

The influence of organic additives (Cit-3Na、EDTA、CTAB et al.) on structure, crystallinity, morphology and upconversion properties for CaSc2O4 nanocrystals was investigated by hydrothermal synthesis. Via adding organic additives, we obtain rod-like and square-like CaSc2O4 nanocrystals. The sample choosing Cit-3Na as organic additive exhibits the best uniformity, monodispersity, narrowest size distribution and strongest red emission, which is enhanced by a factor of 2.5, in comparison with no adding the organic additives. Simultaneously, the upconversion luminescence properties and mechanism of Ln3+/Yb3+ (Ln3+ = Er3+/Tm3+/Ho3+) doped CaSc2O4 nanocrystals were investigated by the spectra distribution and power dependence. The emitting color of CaSc2O4 nanocrystals can be tuned from blue to green and red. The results reveal that CaSc2O4: Er3+/Yb3+ nanocrystals is a perfect red emission material and CaSc2O4 is an ideal host for upconversion luminescence.

Antioxidative enzymes and expression of rbcL gene as tools to monitor heavy metal-related stress in plants

The aim of the study was to evaluate sensitivity and potential applications of selected biomarkers in phytoremediation under complex heavy metal contamination in Sinapis alba L., Robinia pseudoacacia L. and Lupinus luteus L as a potential tools in effective phytoremediation management. The toxicity assessment was conducted using selected measurement endpoints, both classical and advanced, i.e., germination index, roots length, guaiacol peroxidase activity (GPX), chlorophyll and protein content, the amount of total phenolic compounds (TPC) and level of expression of one of the ribulose-bisphosphate carboxylase genes (rbcL). Moreover, the influence of organic additives: cattle, horse manure, and vermicompost on lowering plant abiotic stress caused by complex heavy metal contamination was studied to assess the possible applications of selected stress markers in large scale phytoremediation planning. The results demonstrated the beneficial effects of selected soil additives on plant development. The 5% difference in the quantity of applied amendment caused statistically significant differences in GPX, TPC, chlorophyll content and expression level of rbcL. Among all endpoints, GPX activity, chlorophyll, and phenolic compounds content, as well as the expression of rbcL, turned out to be the most reliable assays for determination of the type and dosage of selected soil amendments (fertilizers) in the assisted phytoremediation process. Selected markers can be used to achieve the desired level of plant abiotic stress and consequently photosynthesis efficiency and CO2 sequestration. The results showed, that presented assays can be used in different taxonomical groups such as Fabaceae for planning effective phytoremediation process.

Influence of organic additives on the behaviour of zinc electroplating from alkaline cyanide-free electrolyte

Two similar polymeric organic compounds from the polyquaternium family were studied as levelling additives in an alkaline cyanide-free zinc plating electrolyte. One additive (LA) has amide bonds between its monomers and the other (LU) has urea unions in its chemical structure. Copper cementation on zinc and gas evolution during aging of the zinc coatings were used to evaluate the effect of the chemical structure of the organic additives on the characteristic deleterious aging process of the coatings when electrodeposited with LA. Scanning electron microscopy and X-ray diffraction were used to follow surface morphology and crystallographic modifications of the coatings during aging. Faster copper cementation kinetics, zinc whiskers growth, blistering of the coating and N2, CH4, CO2 and H2 evolution were observed during accelerated aging of the coatings when LA was used. The coatings produced with LU did not show any aging effect. These studies show the strong influence that subtle changes in the chemical structure of the organic additive may have on the performance of zinc coating during storage.

Adhesion Evaluation of Asphalt-Aggregate Interface Using Surface Free Energy Method

The influence of organic additives (Sasobit and RH) and water on the adhesion of the asphalt-aggregate interface was studied according to the surface free energy theory. Two asphalt binders (SK-70 and SK-90), and two aggregate types (limestone and basalt) were used in this study. The sessile drop method was employed to test surface free energy components of asphalt, organic additives and aggregates. The adhesion models of the asphalt-aggregate interface in dry and wet conditions were established, and the adhesion work was calculated subsequently. The energy ratios were built to evaluate the effect of organic additives and water on the adhesiveness of the asphalt-aggregate interface. The results indicate that the addition of organic additives can enhance the adhesion of the asphalt-aggregate interface in dry conditions, because organic additives reduced the surface free energy of asphalt. However, the organic additives have hydrophobic characteristics and are sensitive to water. As a result, the adhesiveness of the asphalt-aggregate interface of the asphalt containing organic additives in wet conditions sharply decreased due to water damage to asphalt and organic additives. Furthermore, the compatibility of asphalt, aggregate with organic additive was noted and discussed.

Influence of Organic Additives and of Stabilized Polymeric Micelles on the Metalographic Structure of Nanocomposite Zn and Zn-Co Coatings

Influence of Organic Additives and of Stabilized Polymeric Micelles on the Metalographic Structure of Nanocomposite Zn and Zn-Co Coatings

Tin Coatings Electrodeposited from Sulfonic Acid-Based Electrolytes: Tribological Behavior

A high efficiency methane sulfonic acid electrolyte used for tin electrodeposition was studied, and the properties of the resulting deposits were compared to those of tin coatings obtained from an industrial phenol sulfonic acid electrolyte. Cyclic voltammetry was used to study the effect of organic additives on the reduction process to define the composition of the electrolytic bath. Thick tin electrodeposits were obtained on rotating cylinder steel electrodes, and their surface morphology, preferred crystal orientation, surface roughness, micro hardness, and tribological behavior were measured. Smooth, adherent, and bright tin coatings were obtained from the methane sulfonic acid electrolyte, which differed in morphology and texture from tin electrodeposited from the industrial bath. Influence of organic additives on preferred crystal orientation of the coatings was found to be stronger than changing the supporting sulfonic acid type. Tribological tests showed that the two types of deposits have a similar coefficient of friction. However, tin coatings obtained from methane sulfonic electrolytes presented a lower wear resistance and underwent galling at lower loads.

Preparation of spherical calcium phosphate granulates suitable for the biofunctionalization of active brazed titanium alloy coatings.

Titanium-based alloys can be actively brazed onto bio-inert ceramics and potentially be used as biocompatible coatings. To further improve their bioactivity in vivo, introduction of calcium phosphate (CaP)-based granulates onto their surface layer is possible. For this, mechanically stable CaP-based granulates need to be able to withstand the demand of the brazing process. In this study, spherical granulates, made of a calcium phosphate composite composed primarily of β-tricalcium phosphate and hydroxyapatite, a bioactive glass, and a mixture of the previous two, were manufactured by spray drying. The influence of organic additives (Dolapix CE64, trisodium citrate) and solids content (30-80 wt%) in the slurry on the physical characteristics of granulates was investigated. X-ray diffraction, Brunauer, Emmett, Teller specific surface area standard method, scanning electron microscopy, granulate size analysis, and single granule strength were performed. Our results showed that trisodium citrate permitted the production of granulates with regular morphology, high density, and increased failure stress values. The strong granules also withstood the brazing process. These results show that CaP bioactive agents can be generated and be integrated during the demanding metallurgical processes, allowing for one-step bioactivation of metal brazes.

Silver Removal from Polluted Effluents Using a Rotating Cylinder Electrode Reactor (RCE) Potential Application for Valuable Metal Removal from Plating Industry Waste Waters

Plating industry generates great amounts of aqueous effluents (rinses and spent baths), which contain in some cases valuable heavy metals in solution originating from the rinses of coated items (i.e. silver). Because its toxicity and complexity, silver effluents generally are confined and in a few cases is removed. The removal of silver, Ag (I), is traditionally carried out by cementation method where metal is precipitated by chemical reduction with zinc powder. Despite this treatment, effluents obtained with high amounts of zinc (II) are prohibited by international environmental legislation.In this work the application of a rotating cylinder electrode (RCE) in the removal of Ag(I) content from an effluent that contains amounts of Ag (I) similar to wastes generated by plating industry, on the laboratory scale are showed; particularly, it deals with rinse water from the electrolytic silver process. The solutions employed was laboratory-made solutions simulated silver rinse (1500 ppm of Ag(I)) and spent bath (23000 ppm). This process was designed to convert silver ions in solution to metallic silver and influence of organic additives was not taken into account. The generation of metallic silver in the RCE was achieved at Reynolds numbers (Re) ranged between 22682-83183 and limiting current densities (JL) in the range of 7-25 mA cm-2. The removal of Ag (I) is strongly dependent of Ag (I) initial concentration because the simulated rinse solution (1500 ppm Ag(I)) reached 95 % of silver removal in 20 minutes of electrolysis for Re = 52925 and J = 15 mA cm-2; meanwhile for spent bath solution (23000 ppm Ag(I)) at similar operational conditions 95% is reached in 180 min. This behavior is associated with elemental thermodynamic predictions described by faraday law and mainly with different mass transfer mechanisms at such studied concentrations during electrolysis. This second statement was evidenced in previous cyclic voltammometric studies.Plating industry generates great amounts of aqueous effluents (rinses and spent baths), which contain in some cases valuable heavy metals in solution originating from the rinses of coated items (i.e. silver). Because its toxicity and complexity, silver effluents generally are confined and in a few cases is removed. The removal of silver, Ag (I), is traditionally carried out by cementation method where metal is precipitated by chemical reduction with zinc powder. Despite this treatment, effluents obtained with high amounts of zinc (II) are prohibited by international environmental legislation.In this work the application of a rotating cylinder electrode (RCE) in the removal of Ag(I) content from an effluent that contains amounts of Ag (I) similar to wastes generated by plating industry, on the laboratory scale are showed; particularly, it deals with rinse water from the electrolytic silver process. The solutions employed was laboratory-made solutions simulated silver rinse (1500 ppm of Ag(I)) and spent bath (23000 ppm). This process was designed to convert silver ions in solution to metallic silver and influence of organic additives was not taken in account. The generation of metallic silver in the RCE was achieved at Reynolds numbers within 22682 < Re < 83183 interval and limiting current densities (JL) in the range of 7 to 25 mA cm-2. The removal of Ag (I) it strongly dependent of Ag (I) initial concentration because the simulated rinse solution (1500 ppm Ag(I)) reached 95 % of silver removal in 20 minutes of electrolysis for Re = 52925 and J = 15 mA cm-2; meanwhile for spent bath solution (23000 ppm Ag(I)) at similar operational conditions 95% is reached in 180 min. This behavior is associated with elemental thermodynamic predictions described by faraday law and mainly with different mass transfer mechanisms at studied concentrations during electrolysis. Second statement was evidenced in previous voltammometric studies.

Influence of organic additives on the properties of impregnation solutions and on nickel oxide particle size for Ni/Al2O3 catalysts

The introduction of organic additives, such as polyols, sugars or polyacids, in impregnation solutions has been suggested to better control the size of nanoparticles on supported catalysts. The present paper focuses on the roles played by three of these additives, sorbitol, glucose and citric acid, in the preparation of Ni/Al2O3 catalysts. ATR-IR, circular dichroism spectroscopy and viscosity measurements show that the additives act as modifiers of the physical properties of the solutions, by increasing their viscosity via hydrogen bonding, rather than as stable ligands toward Ni2+ ions. Recrystallization of the nickel precursor salt is prevented upon drying. As a consequence, no population of large particles is evidenced by XRD and TPR on the catalysts prepared with additives, unlike reference catalysts prepared by conventional impregnation of nickel nitrate. Adding these organic molecules in the impregnation solution is thus an easy way to narrow the size distribution of NiO nanoparticles without significantly affecting their reducibility.

Influence of Organic Additives on the Efficiency of Process of Preparation of Molding Compounds for Magnesium Silicate Ceramic

The influence of Litoplast series additives on the rheological properties of clay-free magnesium silicate slip is investigated. The use of Litpolast grinding intensifiers makes it possible to decrease the duration of grinding of commercial slip by 3 − 7%. The use of Litoplast M dispersing agents separately and in combination with inorganic surface-active substances substantially reduces the moisture content of commercial slip without the slip losing its rheological properties. This substantially reduces the energy costs in subsequent production of molding compounds.

Influence of etidronic acid and tartaric acid on the growth of different calcite morphologies

AbstractThe influence of organic additives on the crystal growth of different calcite morphologies in two crystallization processes operating under steady state and batch mode is described. The crystal growth kinetics and overgrown morphological observations of rhombohedral, scalenohedral and prismatic calcite seed crystals in the systems containing etidronic acid (HEDP) and tartaric acid (TA) were investigated. The crystallization systems were of low supersaturations (SI<1.1) and of moderate pH (8.0). Kinetic parameters of the crystal growth in the presence of selected additives, such as reduction of the growth rates, rate constant and reduced critical supersaturation were calculated and correlated with additive concentration and different calcite seeds. The results indicate strong interactions of HEDP molecules and weak but specific interactions of TA for calcite surfaces. Interactions occur at the step edges which finally results in the expression of near-{hk0} faces and highly polar faces, consisting of solely Ca layer on the surface, stabilised by TA and HEDP molecules, respectively. The affinity of both additives is significantly higher for scalenohedral and prismatic calcite in contrast to rhombohedral calcite seeds. The effect of calcite seed morphology was attributed to different surface energetics of the predominant crystal faces of the studied calcite seeds.

Influence of organic additives on the degree of grinding of raw material for magnesial silicate ceramic

Processes that are involved in the intensification of grinding of natural (serpentinite) and heat-treated (forsterite) raw material for the production of magnesial silicate ceramic are studied. It is established that the addition of grinding intensifying agents based on polymethylene naphthaline sulphonate produces an increase in the degree of grinding by3–7%or reduces the time needed to grind the material.

Influence of organic additives on electrochemical properties of the positive electrolyte for all-vanadium redox flow battery

Inositol and phytic acid have been employed as organic additives of the positive electrolyte for all-vanadium redox flow battery (VRFB) to improve its stability and electrochemical reversibility. Thermal stability of the V(V) electrolyte could be improved by both inositol and phytic acid additives. The results of cyclic voltammetry (CV), steady polarization curve and electrochemical impedance spectroscopy (EIS) show that the electrochemical activity of the electrolyte with additives is improved compared to the blank one. The diffusion coefficient of V(IV) species with inositol has been increased from 0.71–1.16×10−6 to 3.11–5.15×10−6cm2s−1 and the exchange current density was raised from 2.8×10−3 to 11.7×10−3Acm−2. Moreover, electrochemical results suggest that the positive electrolytes with organic additives have better cycling stability. The VRFB employing positive electrolyte with inositol as additive exhibits excellent charge–discharge behavior with an average energy efficiency of 81.5% at a current density of 30mAcm−2. The UV–visible spectroscopy confirms that new substances in V(V) electrolyte are not formed with both inositol and phytic acid additives.