Other Chemical Treatments

The chemical treatments such as benzoylation, polystyrene maleic anhydride (PSMA) coating and acetylation of short sisal fibers have been found effective in improving fiber matrix adhesion of polystyrene/sisal composites. It has been reported that the 

Bajpai, I. Singh, and J. Madaan, Comparative studies of mechanical and morphological properties of polylactic acid and polypropylene based natural fiber composites./, Reinf. Plast. Compos. 31,1712-1724 (2012). 

Bajpai, 1. Singh, and J. Madaan, Joining of natural fiber reinforced composites using microwave energy Experimental and finite element study. Mater. Des.35, 596-602 (2012). 

---

C99 Other Chemical Treatment R14 Solvents/Organics Recovery - Solvent Extraction R19 Solvents/Organics Recovery - Other... 

C99 Other Chemical Treatment R21 Metals Recovery - Electrolytic... 

SPME/GC/MS is an efficient technique to reveal the presence of resinic substances in archaeological samples. Indeed, volatile terpenes are still present in very old archaeological samples (4000 years old), particularly in the case of compact matrixes, and can be trapped by the SPME fibre. In comparison with methylene chloride extraction, SPME is very specific and allows the direct analysis of the volatile terpenes content in complex mixtures including oils, fats or waxes. For this reason, headspace SPME is the first method to use when analysing an archaeological sample it will either allow the identification of the resin or indicate further sample treatment in order to detect characteristic triterpenes. The method is not really nondestructive because it uses a little of the sample but the same sample can be used for several SPME extractions and then for other chemical treatments. 

It is also necessary for this selection process to take into account the particular cooling system operational conditions (system volume, retention time, circulating water pH, etc.) and several other factors, such as discharge regulations, compatibility with other chemical treatments, and application costs. 

The use of any of the above methods, as detailed, may be regarded as safe and satisfactory for the removal of gross residues no other chemical treatment should... 

As mentioned above, an important factor that controls the performance and especially the electrical properties of CNTs-reinforced composites is the state of dispersion of CNTs. Ultrasonication has been shown to be more effective in dispersing the nanotubes without the need for surfactants or other chemical treatments. Figure 12.5b presents electrical results of samples prepared by using a different composite processing. MWNTS were dispersed in this case in cyclohexane by ultrasonication and the MWNTs suspension was then mixed into a cyclohexane solution of SBR. Mixing was achieved by a further sonication for 30 minutes. Cyclohexane has been chosen in this case on account of the solubility of the rubbers in this solvent. As revealed in Figure 12.5b, the percolation threshold is shifted to a lower nanotube content and from this point of view, measurements of electrical resistivity appears as an indirect tool to evaluate the state of dispersion. 

Wood has many excellent mechanical properties that result from its exceptional combination of microstructural, ultrastructural, and molecular features. The main drawback is its dimensional instability in the presence of moisture. One main reason for modifying wood chemically is to reduce this instability. Other chemical treatments of wood reach the crystalline region of cellulosic microfibrils, destroying the crystalline structure, thus eliminating most of the composite structure of wood. The resulting material does not have any of the characteristic properties of wood but it may be provided with thermoplasticity. A chemical treatment of wood as defined here excludes such radical modifications. We refer to a chemical treatment that may reduce some defects relative to wood utilization and enhance its properties while keeping the bulk of the superior mechanical properties of wood. 

REDUCTION AND OXIDATIVE TREATMENT OF FOSSIL FUELS AND OTHER CHEMICAL TREATMENTS OF WASTE STREAMS... 

Water of constitution is water that is formed when a pure solid is decomposed by heat or other chemical treatment. 

Resistance to corrosion due to external and internal environment, including compatibility with different materials external threats such as soils in which the pipe is buried, groundwater, and so forth, and internal factors such as corrosion inhibition and other chemical treatments... 

Like silicon, the aluminium atoms in zeolites are at the centre of a tetrahedron of oxygen atoms but due to Loewenstein s Rule, the next T-atoms must all be oxygens, giving a single aluminium environment Al[4 Si]. Thus, the Al spectrum does not provide direct information regarding the second coordination sphere. It is, however, very sensitive to whether the A1 coordination is tetrahedral (6 50-70 ppm, wrt Al(H20)g ) or octahedral (6 = 0 ppm wrt A1(H20) ) and when combined with the Si sipectra they can be used to investigate the mechanisms of dealumination and other chemical treatments of zeolites carried out to modify their catalytic and sorptive properties. 

A number of studies have been carried out on the separation and determination of mercury species at concentrations considerably higher (usually two orders of magnitude) than those observed in natural water samples. The methods have included thin layer chromatography, the selective reduction of inorganic and organic mercury species and other chemical treatments, and various ion exchange processes. However, few, if any, of these techniques have been able to satisfactorily determine the species of mercury in waters... 

Other chemical treatments may also be employed for more specific purposes for example, proprietary treatments, usually involving silicone or PTFE, enhance yam-to-yam or fibre-to-fibre lubricity during pulse or flex cleaning, and similarly, where flammability is a potential hazard, padding through commercially available flame retardant compounds may be necessary. 

Liquid transport in paper is, as can be understood from the above examples, a complex issue. Imbibition can occur by various mechanisms and is affected by many factors, such as the structure of the fibre network which controls the size of the capillaries and continuity, fibre surface chemistry and morphology, sizing and other chemical treatments of the fibre surfaces. Each practical case must be carefully thought over in order to make fruitful predictions of the absorbency behaviour and a correct analysis of the experimental data. 

Also discussed in this chapter are the influence of other chemical treatments on the physical and mechanical properties of cellulose-based materials andthe effect of nanoclay on the morphological and mechanical properties of polymer composite. 

Some other Chemical Treatment with Natural Fibers... 

Controls vary with the problem. Chlorination and other chemical treatments commonly used for water-based problems in HVAC equipment may not be effective. Designated smoking areas have not always removed contaminants from the general office environment. When contaminants build up as a result of an inadequate supply of outdoor air, likely sources of contaminants for sick building syndrome are the HVAC systems. When located, the specific causes require removal at the source. 

Here we focus our attention on some new techniques applied during the last decade with the aim of overcoming these difficulties. They are mainly used to study the formation of surface groups on carbon by oxidation or other chemical treatments (e.g., introduction of nitrogenated functions). 

---