Wettability control

Porous inkjet papers are in general created from colloidal dispersions. The eventual random packing of the colloid particles in the coated and dried film creates an open porous structure. It is this open structure that gives photographic-quality inkjet paper its apparently dr/ quality as it comes off the printer. Both the pore structure and pore wettability control the liquid invasion of the coated layer and therefore the final destination of dyes. Dispersion and stability of the colloidal system may require dispersant chemistries specific to the particle and solution composition. In many colloidal systems particle-particle interactions lead to flocculation which in turn leads to an increase in viscosity of the system. The viscosity directly influences the coating process, through the inverse relation between viscosity and maximum coating speed. 

Figure 8-45. Microdischarge-stimulated wettability control droplets are eondensed on the silicon substrate surfaee from the breath pattern is made by the substrate motion with X-Y positioning resolution about 10 pm.

Lee MW, An S, Joshi B, Latthe SS, Yoon SS (2013) Highly efficient wettability control via three-dimensional (3D) suspension of titania nanoparticles in polystyrene nanofibers. ACS Appl Mater Interfaces 5 1232-1239... 

Alyousef, Y., Yao, S.C. (2006) Development of a silicon-based wettability controlled membrane for microscale direct metbanol fuel cells. Microfluidics and Nanofluidics, 2, 337-344. 

Sulfur and its compounds are among the oldest and most widely used pesticides. Elemental sulfur is especially effective as a dust for the control of mites attacking citms, cotton, and field crops and as a protectant against chiggers, Trombicula spp., attacking humans. Sulfur also is a valuable fungicidal diluent for other dust insecticides and is used in wettable form as a spray mixture. Time sulfur has been a standard dormant spray for the control of the San Jose Quadraspidiotuspemiciosus and for other scales and various plant diseases. Time sulfur is a water-soluble mixture of calcium pentasulfide,... 

Rya.nia., The root and stem of the plant yania speciosa family Flacourtiaceae, native to South America, contain from 0.16—0.2% of iasecticidal components, the most important of which is the alkaloid ryanodine [15662-33-9] C25H250 N (8) (mp 219—220°C). This compound is effective as both a contact and a stomach poison. Ryanodine is soluble ia water, methyl alcohol, and most organic solvents but not ia petroleum oils. It is more stable to the action of air and light than pyrethmm or rotenone and has considerable residual action. Ryania has an oral LD q to the rat of 750 mg/kg. The material has shown considerable promise ia the control of the European com borer and codling moth and is used as a wettable powder of ground stems or as a methanohc extract. Ryanodine uncouples the ATP—ADP actomyosia cycle of striated muscle. 

Plasma processing technologies ate used for surface treatments and coatings for plastics, elastomers, glasses, metals, ceramics, etc. Such treatments provide better wear characteristics, thermal stability, color, controlled electrical properties, lubricity, abrasion resistance, barrier properties, adhesion promotion, wettability, blood compatibility, and controlled light transmissivity. 

The main purpose of pesticide formulation is to manufacture a product that has optimum biological efficiency, is convenient to use, and minimizes environmental impacts. The active ingredients are mixed with solvents, adjuvants (boosters), and fillers as necessary to achieve the desired formulation. The types of formulations include wettable powders, soluble concentrates, emulsion concentrates, oil-in-water emulsions, suspension concentrates, suspoemulsions, water-dispersible granules, dry granules, and controlled release, in which the active ingredient is released into the environment from a polymeric carrier, binder, absorbent, or encapsulant at a slow and effective rate. The formulation steps may generate air emissions, liquid effluents, and solid wastes. 

Proper control of the properties of drilling mud is very important for their preparation and maintenance. Although oil-base muds are substantially different from water-base muds, several basic tests (such as specific weight, API funnel viscosity, API filtration, and retort analysis) are run in the same way. The test interpretations, however, are somewhat different. In addition, oil-base muds have several unique properties, such as temperature sensitivity, emulsion stability, aniline point, and oil coating-water wettability that require other tests. Therefore, testing of water and oil-base muds will be considered separately. 

Formations can be oil wet or water wet. The fluid filtrate depends on what is the continuous phase of the completion fluid. Thus the formation wettability can be reduced by wettability charge. This effect can be controlled either by proper fluid selection or by treatment with water wetting additives. 

A surface is that part of an object which is in direct contact with its environment and hence, is most affected by it. The surface properties of solid organic polymers have a strong impact on many, if not most, of their apphcations. The properties and structure of these surfaces are, therefore, of utmost importance. The chemical stmcture and thermodynamic state of polymer surfaces are important factors that determine many of their practical characteristics. Examples of properties affected by polymer surface stmcture include adhesion, wettability, friction, coatability, permeability, dyeabil-ity, gloss, corrosion, surface electrostatic charging, cellular recognition, and biocompatibility. Interfacial characteristics of polymer systems control the domain size and the stability of polymer-polymer dispersions, adhesive strength of laminates and composites, cohesive strength of polymer blends, mechanical properties of adhesive joints, etc. 

Jarvis and Pethica [51] also investigated adhesion as a function of surface wettability but used a diamond tip for its known hydrophobic properties. They also used magnetic force-controlled AFM and applied forces to magnetic material behind the tip to bring the... 

Such layer structure does not allow ns to say a priori that hybridization of DNA will be possible, for it is protected by the octadecylamine layer. In order to control for this possibility, fluorescence measurements were performed. The first indication that hybridization was successful is that after the process, the sample surface became wettable, while before it and after cold hybridization it was not wettable at all. The results of the fluorescence measurements are summarized in Table 10. The results of the specific hybridization are three times more with respect to unspecific hybridization and one order of magnitude more with respect to cold hybridization. Thus, it appears that during a normal hybridization (100% homology) some structural changes and redistribution of the layer takes place. As a result, DNA becomes available for the specific reaction. Such a model also explains why the fluorescence level after unspecific hybridization (10% homology) is higher with respect to cold hybridization. Because the molecules have some mobility when the film is warmed, some DNA from the film could be hybridized on itself, while during cold hybridization this is impossible. 

The residual toxicity of the pure gamma isomer was found to be equivalent to that of ordinary commercial benzene hexachloride. Commercial usage has shown that the residual action is effective for a longer time with dust or wettable powder spray applications than with emulsive solvent-type formulations. The over-all residual life of the chemical is on the order of 4 to 8 days as compared to 14 to 21 days for DDT. This is, of course, adequate residual life for good insect control in most cases and the shorter... 

The use of pure gamma isomer of hexachlorocyclohexane on livestock has also been worked out. It has been found possible to use the wettable powder formulation dispersed in water as a spray on livestock for control of flies, lice, and ticks. Proper dosage and application must be used, of course, but this is again indicative of the safety factor of this insecticide. 

Parathion has been recommended in the state of Washington (3) for the control of various species of mites and orchard aphids. Wettable powders, containing 15 or 25% of parathion, have been used at concentrations ranging from 0.25 to 4 pounds per 100 gallons of water on an experimental basis and from 0.25 to 0.5 pound on a commercial basis. 

Although parathion has not been recommended to date for insect control on soft fruits, there are indications that some injurious insects may be controlled by applications of parathion. Experimental sprays of 1 pound of the 25% wettable powder per 100 gallons of water were applied to soft fruits to determine the amount of parathion residue that would remain on the surface at harvest time. The parathion residue at harvest time is presented in Table I. 

The parathion residue at harvest time resulting from a program of 0.5 to 1 pound of 25% wettable powder applied 45 to 60 days before harvest could be expected to be 0.10 p.p.m. or less. The application of sprays with a concentration in excess of 0.5 to 1 pound (25%) would result in no measurable increase in insect control, waste of materials, and higher parathion spray residues. 

Pome and Stone Fruits. Following the application of DDT and of parathion as wettable powders in control schedules, neither compound has been recovered from the pulp portions of apples, pears, and peaches. A maximum of six spray applications of DDT wettable powder and four spray applications of parathion wettable powder were involved in these studies. As high as 0.4 p.p.m. of DDT and 1.7 p.p.m. of DDT were found in the pulp of apple and pear fruits, respectively, following seasonal treatments with five to six applications of DDT formulated in a petroleum oil fraction. 

Studies on the control of various species of ants show conclusively that aldrin consistently gives control when applied to infested turf at the rate of 1 ounce per 1000 square feet (4 ounces of 25% wettable powder in 200 gallons of water). This dosage is only half of that required when chlordan is the toxicant employed (11,12). 

One of the most difficult parenteral dosage forms to formulate is a suspension. It requires a delicate balance of variables to formulate a product that is easily resuspended and can be ejected through an 18-to 21-gauge needle through its shelf life. To achieve these properties it is necessary to select and carefully maintain particle size distribution, zeta potential, and rheological properties, as well as the manufacturing steps that control wettability and surface tension. The requirements for, limitations in, and differences between the design of injectable suspensions and other suspensions have been previously summarized [17b, 18,19]. 

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