External Additives Research Articles

Effect of Surface Treatment of Carrier on Toner Charging Characteristics

Nowadays the two-component developers are widely used in electrophotography. In two-component developing system toner is tribo-electrically charged by contacting with carrier. In this study, two types of crushed toners categorized according to the constitution of external additives and four types of carriers which are also categorized according to the surface treatment were used for the experiment. The toner charge distribution is changed by the type of carrier coating and concentration of external additives as well. The Aerodynamic size and electrostatic charge distribution of the toner particles are measured individually by E-SPART (Electrical Single Particle Aerodynamic Relaxation Time) analyzer.

Modifying Properties of Aqueous Cetyltrimethylammonium Bromide with External Additives: Ionic Liquid 1-Hexyl-3-methylimidazolium Bromide versus Cosurfactant n-Hexyltrimethylammonium Bromide

Understanding the effect of external additives on the properties of aqueous surfactant solutions is of utmost importance due to widespread applications of surfactant-based systems. Role of ionic liquids (ILs) in this regard may turn out to be crucial as these substances are known to possess unusual properties. To unambiguously understand and establish the role of ILs in modifying properties of aqueous surfactant systems, changes in the physicochemical properties of aqueous cetyltrimethylammonium bromide (CTAB) upon addition of an IL 1-hexyl-3-methylimidazolium bromide ([hmim][Br]) are compared with those when a cosurfactant n-hexyltrimethylammonium bromide (HeTAB) is added to aqueous CTAB. Important physicochemical properties, such as critical micelle concentration (cmc), aggregation number (N(agg)), solution conductance and microfluidity, and average aggregate size and polydispersity, are observed to change as either [hmim][Br] or HeTAB is added to aqueous CTAB; the experimental outcomes clearly imply the changes in most of the physicochemical properties to be significantly more dramatic in case of IL [hmim][Br] addition. The fact that, between the two, only IL [hmim][Br] may show cosolvent-type behavior at high concentrations is evoked to explain the differences in the behavior of the two additives. It is demonstrated that both [hmim][Br] and HeTAB show electrolytic as well as cosurfactant-type behavior within aqueous CTAB when present at low concentrations, with the changes in physicochemical properties being very similar. At high concentrations, although HeTAB still acts as a cosurfactant forming mixed micelles with CTAB, IL [hmim][Br] behaves partly as a cosolvent toward altering the physicochemical properties of aqueous CTAB. The unique role of IL in changing properties of aqueous surfactant systems is demonstrated.

Chronic Inhalation Exposure of Rats for up to 104 Weeks to a Non–Carbon-Based Magnetite Photocopying Toner

Male and female Han Wistar rats were exposed for 6 h/day, 5 days/week for 13 or 104 weeks (whole body) to a magnetite photocopying toner. The toner contained 45% to 50% magnetite, with 45% to 50% styrene acrylic resin and less than 5% external additives, including hydrophobic amorphous silica and proprietary surface functional modifiers. Exposure levels were 1, 5, and 25 mg/m(3) for the 13-week study and 1, 4, and 16 mg/m(3) for the 104-week study. Lung toner burdens averaged 36, 288, and 604 microg per lung after 104 weeks' exposure at 1, 4, and 16 mg/m(3). The lung burdens were lower than have been reported in a similar study with a carbon-based toner. There were no significant effects on weight gain or food consumption in either study, or on clinical pathology parameters examined in the 13-week study. After 104 weeks' exposure at 16 mg/m(3), macroscopic examination revealed dark discoloration of the lungs and associated lymph nodes. Lung weights were significantly elevated by 21% and 14% for male and female rats, respectively. Microscopic findings indicative of a mild inflammatory response were similar in both studies, and included the presence of black-pigmented macrophages in the lungs and tracheobronchial and mediastinal lymph nodes; increased incidences of perivascular/peribronchiolar inflammatory cell infiltration; inflammation of the alveolar ducts (characterized by aggregations of black-pigmented alveolar macrophages and interstitial lymphocytic infiltration); increased cellularity of the bronchiole-associated lymphoid tissue; and a few instances of alveolar ciliated metaplasia. The 104-week study showed no increase in the incidence of pulmonary tumors.

ChemInform Abstract: Three‐Component Synthesis of Amine Derivatives Using Benzylic and Allylic Alcohols as N‐Alkylating Agents in the Absence of External Catalysts and Additives.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Influence of triphenylphosphine on the activity of heterogeneous iridium, rhodium and platinum containing catalysts for the dehydrogenation of saturated hydrocarbons

A series of heterogeneous iridium containing catalysts was synthesized by the incipient wetness method. The support material was silica gel. The heterogeneous catalysts were able to dehydrogenate isopentane to isopentene with very high activities and selectivities. The use of external additives (e.g. PPh 3) in case of the heterogenized iridium complex IrH(CO)(PPh 3) 3 increased the conversion of isopentane up to 30%. Such a conversion rate has been predicted by model calculations of the thermodynamic equilibrium of the dehydrogenation reaction of isopentane.

Competitive Adsorption Between Bis(3-sodiumsulfopropyl disulfide) and Polyalkylene Glycols on Copper Electroplating

In semiconductor copper (Cu) metallization, external organic additives including bis(3-sodiumsulfopropyl disulfide) (SPS) and polyalkylene glycols (PAG) are necessary and widely used to improve the gap-fill capability of Cu electroplating for high-aspect-ratio features. In this study, the interaction of SPS and PAG (SPS–PAG) in the electrolytes was investigated. The results not only show the antisuppression effects of SPS in the presence of PAG, but also indicate the competitive adsorption between SPS and PAG. The proposed mechanism is that when SPS–PAG are added to a plating bath, the Cu-electroplating rate is influenced by competing adsorptions of SPS–PAG and SPS, which disperses PAG species far away from the Cu surface to enhance electroplating rates. The elements (charge-transfer resistance, adsorption-layer resistance, and inductance) of the equivalent circuit simulated using the electrochemistry-impedance spectroscopy data also demonstrate the behavior of SPS–PAG competing reactions.

Three‐Component Synthesis of Amine Derivatives Using Benzylic and Allylic Alcohols as N‐Alkylating Agents in the Absence of External Catalysts and Additives

AbstractThe direct employment of benzylic and allylic alcohols as N‐alkylating agents provides a useful synthetic route for amine derivatives by avoiding the preactivation of the hydroxy groups of alcohols. Herein we report a novel by‐product‐catalyzed three‐component synthesis of amine derivatives from readily available benzylic and allylic alcohols, acyl chlorides (chloroformates or sulfonyl chlorides), and hexamethyldisilazane (HMDS). In the absence of external catalysts and additives, a range of benzylic and allylic alcohols have been transformed into the corresponding N‐alkyl amides (carbamates or sulfonamides) in good to excellent yields. Furthermore, by‐product TMSCl and its decomposition into HCl have been found to be responsible for promoting the three‐component reaction of benzylic (or allylic) alcohols with acyl chlorides (chloroformates or sulfonyl chlorides) and HMDS.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)

Ionic Liquid Induced Changes in the Properties of Aqueous Zwitterionic Surfactant Solution

Modifying properties of aqueous surfactant solutions by addition of external additives is an important area of research. Unusual properties of ionic liquids (ILs) make them ideal candidates for this purpose. Changes in important physicochemical properties of aqueous zwitterionic N-dodecyl- N, N-dimethyl-3-ammonio-1-propanesulfonate (SB-12) surfactant solution upon addition of hydrophilic IL 1-butyl-3-methylimidazolium tetrafluoroborate, [bmim][BF 4], are reported. Dynamic light scattering results indicate a dramatic reduction in the average micellar size in the presence of [bmim][BF 4]; micellar (or micelle-like) aggregation in the presence of as high as 30 wt % [bmim][BF 4] is confirmed. Responses from fluorescence probes are used to obtain critical micelle concentration (cmc), aggregation number ( N agg), and dipolarity and microfluidity of the micellar pseudophase of aqueous SB-12 in the presence of [bmim][BF 4]. In general, increasing the amount of [bmim][BF 4] to 30 wt % results in decrease in N agg and increase in cmc. Increase in the dipolarity and the microfluidity of the probe cybotactic region within the micellar pseudophase is observed on increasing [bmim][BF 4] concentration in the solution. It is attributed to increased water penetration into the micellar pseudophase as [bmim][BF 4] is added to aqueous SB-12. It is proposed that IL [bmim][BF 4] behaves similar to an electrolyte and/or a cosurfactant when present at low concentrations and as a polar cosolvent when present at high concentrations. Electrostatic attraction between cation of IL and anion of zwitterion, and anion of IL and cation of zwitterion at low concentrations of [bmim][BF 4] is evoked to explain the observed changes. Presence of IL as cosolvent appears to reduce the efficiency of micellization process by reducing the hydrophobic effect.

Catalytic homogeneous CH-activation reactions of cyclooctane with [Ir(cod)LL]X complexes (LL = N, N-chelating ligands, amines, phosphines; X = Cl, PF 6)

A series of new [Ir(cod)LL]X complexes (LL = chelating ligands, amines, phosphines; X = Cl, PF 6) was synthesized. The complexes catalyzed the selective homogeneous dehydrogenation of cyclooctane to give cyclooctene up to a rate of 61 turnovers. The activity and selectivity depends on the ligand structure of the corresponding coordination compound. The addition of external additives (amines and phosphines) increased the activities up to 100% in case of PCy 3 and NHPh 2. The dehydrogenation reaction showed a high temperature dependence.

Evolution and Regulatory Impact of Fumed Inorganic Materials in Toners

This presentation will describe how two nano-structured inorganic material classes which are produced by flame processes have been crucial to the technical evolution of the toner industry during the past two decades: fumed metal oxides as external additives and carbon black as the essential pigment. Market forces driving this evolution and increasing additive diversity are the demand for high speed office printers and commercial digital presses and the need for low priced laser printers to make small office and home (SOHO) use affordable. Additionally, ecofriendly printers with reduced energy consumption and zero emissions require the development of toner with low fusing temperatures (low Tg) based on environmentally safe raw materials. Novel fumed silicon/titanium mixed oxides offer the positive tribo-charging benefits of titanium dioxide combined with the surface properties of silica. Acting as effective spacers that prevent re-agglomeration of low Tg toner, fumed sub-micron particles based on both silica and titania have distinct advantages over precipitated and sol-gel-derived materials, respectively. These include; low moisture, high purity, and the complete absence of internal porosity. For improved dispersibility and optimized toner surface coverage, de-agglomerated, chemical and mechanical structure-modified fumed metal oxides have been developed and will be discussed. Lastly, the paper will explore the impact of the ongoing EH&S (environmental, health & safety) discussion on external additives, carbon black and development trends toward safe external additives.

Electrostatic Separation of Color Toner Particles for Material Recovery and Reuse

The separation of color toner waste for recycle and reuse is of great interest due to its potential environmental and economic benefits. This research focuses on the separation of two color toner particles by utilizing their charging properties. In order to facilitate separation, charging properties of toner particles and the resulting interactions of the particles with an electric field were analyzed. Varying both internal and external charge control additives (CCAs) and the concentration of carbon black in the black toner were the primary variables considered to alter the charge of the toners. Subsequently, the parameters that influence particle trajectory of toner particles interacting with an electric field were examined. The purpose was to identify key variables that improve the separation of color toner particles. A numerical model of the charge spectrograph was developed in order to test toners with varying properties as well as to analyze the effects of changes to the system (air velocity, electric field, etc.). The numerical model simulates the particle trajectory within the electric field and predicts the location where particle deposition occurs. Both experimental and numerical results of separating toner particles will be discussed in this presentation.

Effect of bis-(3-sodiumsulfopropyl disulfide) byproducts on copper defects after chemical mechanical polishing

In the semiconductor metallization process, the superior gap-fill capability of copper (Cu) electroplating is mainly due to external additives, such as bis-(3-sodiumsulfopropyl disulfide) (SPS), which is used as an accelerator. This study demonstrates that the byproducts of SPS induced Cu defects after a chemical-mechanical-polishing (CMP) process. In conventional cyclic-voltammetric-stripping analysis, the byproducts generated from organic additives are very difficult to quantify. In this study, the authors used mass-spectrum analysis to quantify SPS byproducts and found that the SPS byproduct, 1,3-propanedisulfonic acid, correlated with the formation of Cu defects because it influenced the properties of electroplated Cu films and the chemical corrosion rate, then induced defects after the CMP process.

Tuning of the activity and induction period of double metal cyanide catalyzed ring-opening polymerizations of propylene oxide by using ionic liquids

Polymerizations of propylene oxide (PO) have been carried out by using double metal cyanide (DMC) catalyst prepared by reacting ZnCl 2 and K 3[Co(CN) 6] in the presence of tert-butyl alcohol as a complexing agents. The DMC catalyst of the molecular formula, Zn 2.3Cl 1.0[Co(CN) 6] 1.0·2.0 t BuOH·1.0H 2O, is characterized by gas sorption measurements, infrared spectroscopy and X-ray powder diffraction. The structure of DMC catalyst with negligible surface area and broadened X-ray diffraction peaks is different from that of Prussian blue analogue, Zn 3[Co(CN) 6] 2·12H 2O of microporous crystalline materials. The PO polymerization behavior is tunable by combining it with various imidazolium based ionic liquids (ILs) as external additives. Thus, (1) they make the zinc-monomer bond faster activated during the initial stage of polymerization, (2) they make the zinc-monomer bond more active, (3) they stabilize the polymerization centers and prevent their decomposition, and (4) they improve important polymer properties such as molecular weight, viscosity and unsaturation level. The maximum rate of polymerization ( R p,max) of DMC catalyst increases from 2587 to 27,222 g-polymer/g-cat h by combining with 1-ethyl-3-methylimidazolium chloride (emimCl, [emimCl]/[Zn] = 1.25) at 115 °C. The induction period as the time to reach R p,max becomes short from 321 min for DMC catalyst to 29 min for DMC/emimCl binary catalyst. The unsaturation value of polyol (0.017 mequiv./g) produced by DMC decreases to 0.005 mequiv./g by simply combining with IL. The molecular weight polyol produced by DMC catalyst increases from M n = 3700 to more than 6000, and the viscosity of polyol decreases by combining with ILs.

A RESEARCH NOTE ON RHEOLOGICAL BEHAVIOR OF SOME PROCESSED PRODUCTS FROM CACTUS PEAR (OPUNTIA FICUS‐INDICA [L.] MILL.)

ABSTRACT A study of some textural and rheological properties of cactus pear products was carried out in this research. The parameters of brittleness and hardness in peeled cactus pears in syrup (PCPS), and the compression stress in the sweetened pulp from cactus pears with partial addition of their skins (SPCPS) and in the marmalade from cactus pear skins (MCPS) were evaluated. Flow behavior was only evaluated in SPCPS and MCPS. A significant variation of the maximum force between different samples of PCPS in the range of 544.3–975.3 N was determined, while the deformation was 17.1–21.2 mm. In the SPCPS and MCPS products, the maximum stresses were low, 0.254 and 0.366 N/mm2, although the deformation was of 28.8 and 29.07 mm, respectively. SPCPS was a pseudoplastic fluid, with a better fit to the general model of Herschel–Buckley. Meanwhile, MCPS was represented by a polynomial model of third order. PRACTICAL APPLICATIONSThe results of this study indicate that there is a relatively wide interval in the degree of ripeness of the fruits, detected by instrumental evaluation, which can be used for the development of the peeled cactus pears in syrup product despite the previous selection of the fruits carried out in the elaboration process and are accepted by trained testers without being a sensorial defect. On the other hand, the partial or total incorporation of the skins in sweetened pulp from cactus pears with partial addition of their skins and in marmalade from cactus pear skins semisolid products, respectively, allows a greater use of the fruit, while the mixture of pectin and mucilage in the skins contributes to increasing the consistency without making necessary the addition as external additives.

ESR signals from silk fabrics irradiated by UV -rays

ESR studies were done on UV-ray irradiated silk fabric samples at room temperature. Different types of UV lamps were used and similar ESR signals were observed. The results indicate that UV-rays can produce free radicals for graft-copolymerization of monomer onto silk fibers without external additives or co additives, Also, radicals in silk fabrics irradiated by UV-rays are purer than that irradiated by γ-rays. The study suggests that UV-lights may be a better tool to improve properties of silk fabrics by grafting monomers onto the polymer chains.

Tuning of activity, induction period and polymer properties of double metal cyanide catalyzed ring-opening polymerizations of propylene oxide by using quaternary ammonium salts

Polymerizations of propylene oxide (PO) have been carried out by using double metal cyanide (DMC) catalyst prepared by reacting ZnCl2 and K3[Co(CN)6] in the presence of tert-butyl alcohol (tBuOH) as a complexing agent. The catalytic activity and the induction period for PO polymerizations catalyzed by DMC are tunable by using various quaternary ammonium salts (QAS) as external additives. The DMC/QAS binary catalyst improves polymer properties as well such as molecular weight, molecular weight distribution, viscosity, and unsaturation level.

Optimisation of Nitrification-Denitrification Process in a SBR for the Treatment of Reject Water Via Nitrite

An optimal sequencing batch reactor (SBR) strategy is proposed for Biological Nitrogen Removal (BNR) via nitrite of reject water (800-900 NH4 +-N mg 1−1) from mesophilic (35 °C) anaerobic sludge digester of a Spanish Municipal Wastewater Treatment Plant (WWTP). Two lab-scale SBR with control of temperature were studied with external COD addition for denitrification which was necessary due to the lack of readily biodegradable carbon source. Process kinetics were compared through the specific Ammonium Uptake Rate (sAUR) finding the appropriate operational sequences when working at 32°C and 8 hour cycle length. Every operating cycle was carried out with a sludge retention time of 11 days, hydraulic retention time around 1 day and 2500±250 mg VSS 1−1. In order to avoid nitrate formation and thus save costs, the oxygen concentration was maintained below 1 mg 1−1 during aerobic periods and pH remained within an optimal range (7.5-9) alternating different aerobic-anoxic subcycles inside the operational cycle. With this strategy, the range of alkalinity could be controlled avoiding the addition of external additives and nitrite accumulation was prevented. Therefore, the reached sAUR was 22 mg NH4 +-N g−1 VSS h−1 and the total nitrogen removal was 0.8 kg N(d m3)−1.

The control of electrostatic characteristics in toner type paper‐like display

The toner type paper‐like display (PLD) has been developed with two polymer particles having opposite polarity composed of polymer, colorant and external additives (nano‐sized silica). Nano‐sized silica with triboelectric charge was used for the charge control agent (CCA) and influenced on the electrostatic properties of the silica‐coated polymer particles. The surface morphology and the cohesiveness of silica‐coated polymer particles were changed with the silica coating time. From these results, it was verified that the PLD cell using silica‐coated particles (200 seconds) shows a good white appearance and low driving voltage.

Novel Fumed Mixed Silica-Titania (FM-Si/Ti) Core Materials for a New Class of External Toner Additives

Fumed mixed silica-titania (FM-Si/Ti) core materials and their corresponding hydrophobized counterparts are compared with respect to their applicability as external additives for electrophotographic toners using toner flowability and Tribo-Electrostatic Charge (T-ESC) stability under extended activation periods as well as L/L and H/H conditions. Flowability studies, which included angle of repose and tapped density measurements, showed differences in the toner flow enhancement with titania and FM-Si/Ti compared to silica alone, both under static and dynamic conditions. The influence of silica in FM-Si/Ti on the initial charge-up behavior was also observed in T-ESC measurements. The differences were explained by TEM investigations, indicating the importance of the silica/titania ratio of the nano-particle structure. In addition, volume resistivity (Ω·cm) studies showed that the structure strongly relates to the electro-physical properties of the FM-Si/Ti. The influences of a thin, encapsulating silica layer on the titania core of mixed oxides are described in detail.

Co(III) and Ni(II) Complexes Containing Bioactive Ligands: Synthesis, DNA Binding, and Photocleavage Studies

DNA binding and photocleavage characteristics of a series of mixed ligand complexes of the type [M(bpy)2qbdp](PF6)n·xH2O (where M = Co(III) or Ni(II), bpy = 2.2′-bipryidine, qbdp = Quinolino[3,2-b]benzodiazepine, n = 3 or 2 and x = 5 or 2) have been investigated. The DNA binding property of the complexes with calf thymus DNA has been investigated by using absorption spectra, viscosity measurements, as well as thermal denaturation studies. Intrinsic binding constant (K b) has been estimated under similar set of experimental conditions. Absorption spectral studies indicate that the Co(III) and Ni(II) complexes intercalate between the base pairs of the CT-DNA tightly with intrinsic DNA binding constant of 1.3 × 106 and 3.1 × 105 M−1 in Tris-HCl buffer containing 50 mM NaCl, respectively. The proposed DNA binding mode supports the large enhancement in the relative viscosity of DNA on binding to quinolo[3,2-b]benzodiazepine. The oxidative as well as photo-induced cleavage reactions were monitered by gel electrophoresis for both complexes. The photocleavage experiments showed that the cobalt(III) complex can cleave pUC19 DNA effectively in the absence of external additives as an effective inorganic nuclease.