In-situ processes

The in situ process is simpler because it requires less material handling (35) however, this process has been used only for resole resins. When phenol is used, the reaction system is initially one-phase alkylated phenols and bisphenol A present special problems. As the reaction with formaldehyde progresses at 80—100°C, the resin becomes water-insoluble and phase separation takes place. Catalysts such as hexa produce an early phase separation, whereas NaOH-based resins retain water solubiUty to a higher molecular weight. If the reaction medium contains a protective coUoid at phase separation, a resin-in-water dispersion forms. Alternatively, the protective coUoid can be added later in the reaction sequence, in which case the reaction mass may temporarily be a water-in-resin dispersion. The protective coUoid serves to assist particle formation and stabUizes the final particles against coalescence. Some examples of protective coUoids are poly(vinyl alcohol), gum arabic, and hydroxyethjlceUulose. 

High-resolution transmission electron microscopy (HREM) is the technique best suited for the structural characterization of nanometer-sized graphitic particles. In-situ processing of fullerene-related structures may be performed, and it has been shown that carbonaceous materials transform themselves into quasi-spherical onion-like graphitic particles under the effect of intense electron irradiation[l 1],... 

These studies show that the perfluoroalkyletherlithium compound shown in equation 42 has greater thermal stability than the perfluorooctyllithium, which must be prepared in situ. This in situ process has been very useful in the synthesis of other shorter chain perfluoroalkyllithium compounds Pentafluoroethyllithium can be conveniently prepared in this manner and reacts with numerous esters to yield tertiary alcohols [76, 77] in excellent yields. 

In-Situ Processing of Energy and Mineral Resonrces (Chapter 6)... 

The committee recommends that the Bureau fund a modest number of university-based centers focused on in-situ processing of dilute resources. This initiative would complement the one proposed for DOE. 

Bowlen GF, DS Kosson (1995) In situ processes for bioremediation of BTEX and petroleum fuel products. In Microbial transformation and Degradation of Toxic Organic Chemicals (Eds LY Young, CE Cerni-glia), pp. 515-545. Wiley-Liss, New York. 

Another classification of remediation technologies describes where the action is taking place. Ex situ methods are those applied to excavated soil and in situ processes are those applied to the soil in its original location. On-site techniques are those that take place on the contaminated site they can be either ex situ or in situ. Off-site processes treat the excavated soil in fixed industrial facilities, away from the contaminated site. 

An important variant of the in situ process is foaming within a flexible cover. As the foam expands, it forces the cover outwards to conform to the interior shape pf a mold. We make extensive use of this process to make seat cushions for automobiles and office furniture. 

D. D. L. Chung, X-ray Diffraction At Elevated Temperatures a Method for in Situ Process Analysis. Chichester John Wiley, 1993. 

Alkyl anthrahydroquinone/alkyl anthraquinone in situ process, 24 173 Alkylanthrahydroquinones, 14 43, 44 oxidation of, 14 50... 

Petit C, Mendoza B, O Donnell D, Bandosz TJ. Effect of graphite features on the properties of Metal-Organic Framework/Graphite hybrid materials prepared using an in situ process, Langmuir 2011, TJ, 10234-10242. 

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