Surface Modification Of Pigments Research Articles

Natural pigment: Preparation of brown pigment from lignin biomass for coloring application

Nanopigment based coatings have attracted considerable interest due to their high surface area, enhanced covering strength, resistance to scratch and abrasion properties. The preparation of nano pigments from industrial waste is challenging and can potentially be used in various industrial applications. As per environmental concerns, utilization of insoluble residues such as black liquor separated from paper and pulp industry waste as value added products is essential for industrial waste management. Tailoring of nanosized pigment colorants with improved surface covering properties from the industrial waste black liquor has been proposed. The acidified and precipitated insoluble organic part of black liquor was used for pigment preparation. Surface modification of pigment with silica coating, through sol-gel method, using synthesized Gemini surfactant, was adopted for size reduction. The prepared nanopigments were characterised through Fourier Transform Infrared Spectroscopy (FT-IR), Reflectance measurement and Transmission Electron Microscope (TEM). The results for optical studies of the prepared pigment confirms the suitability of this surface modified pigment as a brown coloring agent. From the DLS measurements, the dispersion property of prepared pigment was found to be monodispersed with a narrow size distribution of approximately 50–200 nm. The industrial applicability of such nano pigment was analysed by utilizing it as colorant for the leather surface coating as well as in plastics. Commercial viability of nano-pigments as coloring agents, adds value to the paper and pulp industry waste in a sustainable way.

Surface Modification of Titanium Dioxide under Ultrasonic Treatment

The surface modification of titanium dioxide in aqueous dispersions of specially tailor-made periodic acrylic acid/isobutylene copolymers by ultrasonic treatment was studied. The pigment surface modification by the above copolymers was comparatively investigated regarding conventional adsorption as contrasted to an ultrasonic treatment assisted procedure. The course and efficiency of the polymer adsorption onto the pigment surface was quantified by electrokinetic sonic amplitude measurements. The higher efficiency of the pigment surface coating by the copolymers as achieved by ultrasonic treatment and is a consequence of ultrasonically induced pigment surface activation.

SURFACE MODIFICATION OF TITANIUM DIOXIDE NANOPARTICLES WITH ACRYLIC ACID/ISOBUTYLENE COPOLYMER UNDER ULTRASONIC TREATMENT

The influence of the ultrasonic treatment of block copolymer solution on its solid-liquid interface behavior was investigated in detail. The surface modification of titanium dioxide nanoparticles in aqueous dispersions of specially tailor-made periodic acrylic acid/isobutylene copolymer by ultrasonic treatment was studied in order to get new approaches for the creation of hybrid composite materials or polymer coatings. The pigment surface modification by the above copolymer was comparatively investigated regarding conventional adsorption as contrasted to an ultrasonic treatment assisted procedure. The course and efficiency of the polymer adsorption onto the pigment surface were quantified by electrokinetic sonic amplitude measurements. The higher efficiency of the pigment surface coating by the copolymer as achieved by ultrasonic treatment in comparison to conventional adsorption is a consequence of ultrasonically induced pigment surface activation. Two perspective avenues of the utilization of the discovered effects for creation of organic-inorganic composite materials are anticipated: the nanoparticles could first be treated by ultrasound in the presence of polymers and so create a surface modifying coating and the second option is an entrainment of the nanoparticles into the monomer matrix which can be polymerized afterward yielding a polymer with immobilized nanoparticles.

Characteristics of pigments, modification, and their functionalities

AbstractNovel treatments of pigments with inorganic materials have tremendous industrial and commercial prospects. Specific treatment of pigment has a marked effect on its behavior during application. The treatment allows a broad modification of the surface characteristics of pigment particles which leads to improved functionalities. Surface modification of pigments is achieved via coating, polymerization with modifying reagent, treatment with derivatives or polymers, which alter either the optical, conductivity or dispersibility during processing and application. These and many other distinguishing factors that affect the characteristics of pigments such as the class, crystal structure, particle morphology, particle size, hiding power, pigment volume concentration, surface character, and surface treatment have been reviewed. Various organic pigments such as those from fungus and bacteria, and the various families of pigment types such as metallic pigment, light interference, and diffractive pigments which presents decorative quality such as leafing, nonleafing, pearlscent, and Fabry‐Perot effects on substrates have also been reviewed in addition to those from inorganic sources with emphasis on the structure and physiochemical modifications using metal and nonmetal Ions.

Study of nanostructure of polymer adsorption layers on the particles surface of titanium dioxide

The surface modification of titanium dioxide in aqueous dispersions of specially tailor-made periodic acrylic acid/isobutylene copolymers, poly(acrylic acid)/polystyrene graft copolymers, and hydrophobically modified polyethyleneoxide urethane by ultrasonic treatment was studied. The pigment surface modification by the above copolymers was comparatively investigated regarding conventional adsorption as contrasted to an ultrasonic treatment assisted procedure. The course and efficiency of the polymer adsorption onto the pigment surface was quantified by electrokinetic sonic amplitude measurements. The higher efficiency of the pigment surface coating by the copolymers as achieved by ultrasonic treatment varies with the copolymer architecture and is a consequence of ultrasonically induced pigment surface activation.

Diketopyrrolopyrrole pigment core@multi-layer SiO2 shell with improved photochemical stability

A model organic pigment (diketopyrrolopyrrole) is encapsulated by a silica coating in order to improve its photochemical stability. Unlike in previous works where single-layer silica coatings were used for similar purposes, we here propose creation of a multi-layer silica shell synthesized via in-situ sol-gel method, which should significantly improve the homogeneity and thus the protection ability of the coating. This is done by repeating the basic two-step process (pigment surface modification and silica encapsulation) several times, creating the final protective shell in a layer-by-layer fashion. The compositional and structural properties of the prepared coatings is studied using Fourier-transform infrared spectroscopy, differential thermal and thermogravimetric analysis, nitrogen adsorption measurements and transmission electron microscopy. Photochemical stability of non-encapsulated and encapsulated pigment particles is evaluated via the so-called fast-irradiation method. Various correlations between the essential coating properties, such as thickness, porosity, SiO2 content, and the corresponding photochemical stability of the samples are established and discussed in detail. As a whole, our results confirm the basic hypothesis, that multiple-layered silica shells show improved pigment protection ability in comparison to the single-layer coatings.

Ultrasonic Treatment Enhanced Surface Modification of Titanium Oxide by Tailor-Made Surface-Active Polymers

The surface modification of titanium dioxide in aqueous dispersions of specially tailor-made periodic acrylic acid/isobutylene copolymers, poly(acrylic acid)/polystyrene graft copolymers, and hydrophobically modified polyethyleneoxide urethane (HEUR) by ultrasonic treatment was studied. The pigment surface modification by the above copolymers was comparatively investigated regarding conventional adsorption as contrasted to an ultrasonic treatment assisted procedure. The course and efficiency of the polymer adsorpption onto the pigment surface was quantified by electrokinetic sonic amplitude measurements. The higher efficiency of the pigment surface coating by the copolymers as achieved by ultrasonic treatment varies with the copolymer architecture and is a consequence of ultrasonically induced pigment surface activation.

Creation of Coatings by Temperature-Controlled Polymer Deposition

In this paper, the results of the recent studies on application of lower critical solution temperature (LCST) phenomena of polymer solutions to the surface modification of flat and spherical substrates are reported. It was found that a controlled polymer deposition can be achieved upon prevailing of the LCST, a peculiar surface topology of polymer coating and particles those remarkably effective in stabilizing pigment dispersiions. Second, the finding is that the temperature induces polymer deposition as the coprecipitation of a finely dispersed component on the substrate surface. That goes along with the polymer deposition after exceeding of the LCST which in turn allows for the tailored surface modification of pigments in that particulate additiives can be incorporated into the surface modifying coating.

Preparation of Composite Powder and Properties by Surface Modification of Inorganic Pigments for Papermaking

In this study, functional composite-pigment was prepared by a dry impact-blending method, using the inorganic materials used for coating of titanium dioxide, GCC, clay, and talc. After considering the particle size of inorganic pigment, the selected core powder and fine powder were mixed at a suitable mixing ratio. When powder was electrified, their fine particles could adhere by static electricity on the larger ones termed ‘core particles’, and then form an ordered mixture. During the surface modification of pigments, the energy caused by fine powder adhering to core particles was measured, and utilized in examining the efficiency of the change of particle size surface modification. Afterward, these were susceptible to being composited by impact force, resulting from very high-speed air circulation. After putting these surface modified pigments in water, their static electricity properties were measured by particle charge detector and Zeta potential tester. From these results, it was revealed that the elemental powder properties of papermaking inorganic pigment could be improved.

Surface Modification in Aqueous Dispersions with Thermo-Responsive Poly(methylvinylether) Copolymers in Combination with Ultrasonic Treatment

The process of surface modification of hyd- rophobic organic pigments (copper phthalocyanine (CuPc) and carbon black) as well as a hydrophilic inorganic pigment (titanium dioxide) in aqueous dispersions by employing tailor-made thermo-responsive copolymers, and the colloidal stability have been studied. The pigment surface modification is achieved by conventional adsor- ption and by (thermo)preci pitation of amphiphilic methyl vinyl ether (MVE) containing polyvinylether block and PMVE graft copolymers with poly(ethylene oxide) side chains exhibiting a lower critical solution temperature (LCST). The effect of mechanical treatment of the pigment dispersion by ultrasonic power alone or in combination with the LCST property was investigated. The course of the pigment surface coating process was followed by the Elec- trokinetic Sonic Amplitude (ESA) method. The tempera- ture-controlled sorption of PMVE-g-PEO graft copolymers on both inorganic and organic pigment surface was investigated. It was found that ultrasonic treatment together with LCST thermoprecipitation is a promising method for the surface modification of pigments with regard to dispersion stability.

Effect of ultrasonic treatment on structure and properties of ethylhydroxyethylcellulose polymer adsorption layer on inorganic pigments in aqueous dispersion

The course and the result of the surface modification of titanium dioxide and ferrous oxide pigments in aqueous dispersion by ethylhydroxyethylcellulose (EHEC) without and with mechanical treatment of the dispersion by ultrasonic power was studied by the electrokinetic sonic amplitude (ESA) method. The evaluation of the ESA data showed that the ultrasonic treatment causes a significant thickness increase of the EHEC layer on the pigment which is primarily attributed to the ultrasonically induced activation of the pigment surface. The thickness of the polymer adsorption layer derived from ESA measurements was confirmed by TEM investigations. The ultrasonic treatment leads to significant changes of the properties of the adsorption layers and is a promising method for the surface modification of pigments with regard to dispersion stability.

Application of thermo-responsive poly(methyl vinyl ether) containing copolymers in combination with ultrasonic treatment for pigment surface modification in pigment dispersions

The process of surface modification of hydrophobic organic (copper phthalocyanine (CuPc)) as well as hydrophilic inorganic pigments (titanium dioxide) in aqueous dispersions by employing tailor-made thermo-responsive copolymers and the colloidal stability have been studied as a function of temperature. The pigment surface modification is achieved by conventional adsorption and by thermoprecipitation of amphiphilic methyl vinyl ether (MVE) containing block and graft copolymers, exhibiting a lower critical solution temperature (LCST), with poly(isobutyl vinyl ether) blocks and poly(ethylene oxide) side chains, respectively. The effect of mechanical treatment of the pigment dispersion by ultrasonic power alone or in combination with the LCST property was investigated. The course of the pigment surface coating process was followed by the electrokinetic sonic amplitude (ESA) method. The temperature-controlled sorption of PMVE- g-PEO graft copolymers on both inorganic and organic pigment surfaces was investigated. It was found that ultrasonic treatment together with LCST thermoprecipitation is a promising method for the surface modification of pigments with regard to dispersion stability.

Novel procedure for polymer coatings of nanoscopic surface topology

A new coating technique based on the so-called lower critical solution temperature (LCST) phase transition phenomena known from polymer solutions has been studied. Contrary to the commonly-known features that precipitation from solution occurs upon cooling (or solvent evaporation) or by a precipitant, LCST behaviour means a coagulation and precipitation of the polymer from solution upon heating, once a critical temperature is exceeded. This technology not only allows a controlled surface modification of pigments or flat substrates by an organic polymer coating layer, but also allows one to introduce specific surface features of nanoscopic to mesoscopic dimensions. The surface topology may be reversibly varied from a regular, almost close-packed, mesoscopic hemisphere texture to a nanoscopic roughness or rendered evenly smooth.

Thermo‐analytical characterization of pigmented waterborne basecoats

Modern waterborne basecoats contain a high degree of pigments to fulfill the wanted high brilliance and optical effects. Different kinds of pigment systems (color, pearl-effect, aluminum flakes) in a model binder matrix were investigated by Dynamic Mechanical Analysis (DMA) measurements at different pigment volume concentrations (PVC). To get more detailed information concerning the pigment binder interaction partially the binder system and the surface modification of pigments were varied. The results were correlated to technological tests (stone chip, adhesion). It can be shown, that special effects in waterborne basecoats like influences of resins or pigment-binder interaction can be investigated by means of DMA in a quite effective way. Thus it is possible to optimize one layer in a coating system in terms of its mechanical properties by reformulating the binder matrix and by a suitable surface treatment of the pigments.

Surface Modification of Pigments with Temperature-Responsive Polymer Grafted by Plasma-Induced Polymerization.

In order to develop temperature-responsive dispersing systems, we have grafted poly(N-isopropylacrylamide) (PNIPA), which is a temperature-responsive polymer having a lower critical solution temperature (LCST) at 32°C, onto carbon black (CB) by plasma-induced graft polymerization technique. CB was treated with H2O and/or O2 plasma, to which aqueous solution of the monomer (NIPA) was introduced, resulted in simultaneous graft polymerization. The dispersibility of the PNIPA-grafted CB in water at 25 and 35°C was investigated by the measurement of the transmittance of visible light (500nm). The most of the PNIPA-grafted CB showed better dispersibility at 25°C (below the LCST) than at 35°C (above the LCST). In many graft polymerization conditions, CB grafted in 2wt% of the monomer concentration with ultrasonic irradiation at room temperature showed the most clear temperature response of the dispersibility in water.

環状ジメチルシロキサンを用いたCVD法による顔料の表面処理

環状ジメチルシロキサンを用いたCVD法による顔料の表面処理