Polystyrene fabrication technique

An important aspect of this enhancement strategy is its compatibility with current fabrication techniques, in particular polymer processing technology. The technique of micro-injection moulding was employed to produce polystyrene chips with an integrated array of cone structures intended for use in an aqueous environment. 

Whereas all conventional thermoplastic fabrication techniques have been successfully employed to convert pellets of HIPS into useful articles, extrusion (film, sheet, profile and multi-layer) and injection molding (solid, structural foam and gas-assist) are the predominant processing technologies. Innovative hardware technologies, in both extrusion and injection molding, have provided means to combine less expensive materials, such as polystyrene, with polymers or structures offering key performance characteristics. 

Fazio F, Bryan MC, Lee HK, Chang A, Wong CH. Assembly of sugars on polystyrene plates a new facile microarray fabrication technique. Tetra. Lett. 2004 45(12) 2689-2692. 

Different fabrication techniques have been used for manufacturing photonic band-gap structures. Among them are layer-by-layer structure formation [150] and crystallization of polystyrene nanoparticles. The latter possess a diameter of 200 nm. They are infiltrated with coumarin-503. This dye exhibits strong... 

The other most common fabrication technique for the polystyrene family is injection molding, most frequently accomplished by reciprocating screw and screw preplasticiator machines (22). 

In a similar work, the synthesis of a composite with iron oxide particles and sul-fonated cross-linked polystyrene (SXLPS) for application in the PEMs for fuel cells was described (Brijmohan and Shaw 2007). The technique used for the polymerization was similar to the miniemulsion polymerization (Ramirez and Landfester 2003). However, some modification to the procedure was required to make the cross-linked and functional polymer-iron oxide composites. Also reported was the membrane fabrication process, which inclndes the alignment of synthesized particles in a high-performance snlfonated poly(etherketoneketone) (SPEKK) matrix (Gasa et al. 2006), and the properties of such PEMs for fuel cell applications. The final properties of the membrane depend on various factors, such as the lEC, the matrix, and the size of the particles. However, the main emphasis of the research was to demonstrate a useful membrane-fabrication technique that can be utilized to enhance the conductivity of the PEMs. 

In this chapter, we will cover the various lens fabrication techniques. The lens materials range from polymers to glass and include polycarbonates, ultraviolet (UV)-curable epoxies, polyimides, and polystyrenes. These techniques can produce lenses with numerical apertures (NAs) less than 0.6, typically 0.1 to 0.3 [7]. Low NA values are attributable to the surface profiles and refractive indices of microlenses. 

Li et al. employed LbL self-assembly to construct multilayered films on top of nonwoven PCL fibers. The multilayered film consisted of gelatin and polystyrene salt. The top layer was further coated with calcium phosphate. The fabricated scaffold was tested for its potential in bone tissue engineering. Results indicated an enhanced cell proliferation for the LbL-assembled scaffolds (Li et al., 2008). Zhang et al. (2005) employed LbL fabrication technique to form multilayers consisting of type I collagen and hyaluronic acid and were able to generate fibrous multilayered structures that supported the attachment of chondrosarcoma cells. 

Since multiple electrical and optical functionality must be combined in the fabrication of an OLED, many workers have turned to the techniques of molecular self-assembly in order to optimize the microstructure of the materials used. In turn, such approaches necessitate the incorporation of additional chemical functionality into the molecules. For example, the successive dipping of a substrate into solutions of polyanion and polycation leads to the deposition of poly-ionic bilayers [59, 60]. Since the precursor form of PPV is cationic, this is a very appealing way to tailor its properties. Anionic polymers that have been studied include sulfonatcd polystyrene [59] and sulfonatcd polyanilinc 159, 60]. Thermal conversion of the precursor PPV then results in an electroluminescent blended polymer film. 

Reproducibility of immunoassay results can be adversely affected by variations in the chemical formulation of different lots of plastics used as the solid phase (see section on Solid Phase Materials). Therefore, use of a thin coating of one lot of plastic over a material like metal for millions of tests could be important in standardizing immunoassay techniques. Extremely small amounts of polycarbonate (or other plastics) are required for putting a thin coating on steel beads. Therefore, one small commercial lot of plastic (e.g., one 212 pound 4x8 foot sheet of polycarbonate) would be sufficient to prepare beads for over 100 million tests. Plastic solid phases employing Microtiter plates, test tubes, and polystyrene beads require relatively large quantities of plastic for fabrication and, con-... 

The general purpose thermoplastics introduced in the 1930 s and 1940 s were readily fabricated by extrusion and injection molding techniques. Thermoplastics, such as polyvinyl chloride, polystyrene and polyethylene were resistant to mineral acids at temperatures up to 60OC but they could not be used at higher temperatures, such as that of boiling water. These large volume plastics had other characteristic deficiencies which were overcome by the use of additives. 

Hollow fibers and spheres of zeolite (labeled as HFZ and HSZ, respectively) were successfully fabricated using carbon fibers and polystyrene (PS) spheres as templates respectively, through layer-by-layer technique, coupled with removal of the templates by calcination. The optimum performance conditions to obtain these kinds of materials were systematically studied. The wall thickness and composition of these novel materials can be readily tailored by varying the number of nanozeolite/PDDA (poly(diallyldimethyl ammonium chloride)) deposition cycles and zeolite type used, respectively. The properties of these novel materials were characterized by means of XRD, IR and SEM. 

Mishra, K.K. Khardekar, R.K. Singh, R. Pant, H.C. Fabrication of polystyrene hollow microspheres as laser fusion targets by optimized density matched emulsion technique and characterization. Pramana, Journal of Physics 59(1), 113-131, 2002. 

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