Regulations controlling diesel exhaust become more exacting with each passing year. Accordingly, diesel fuel properties are constantly being analyzed in an attempt to further reduce fuel emissions. There are many options, most often refinement processes or improving the cetane number. Essentially, short and branched ethers (used in gasoline) have a good octane number but poor cetane number, while those ethers used in diesel are linear and have a comparatively long chain (ideally 9 or more carbons). Di-n pentyl ether (DNPE) has shown most effective in reducing emissions, and is also relatively simple to synthesize via the bimolecular dehydration of 1-pentanol on acid catalysts, as seen below.

However, the dehydration reaction results in quite a lot of byproducts, including other ethers. As such, a selective catalyst is required to favor production of DNPE by reducing the amount of alkenes. Increased selectivity can be accomplished via gel-type acidic resins at a reaction temperature of 150°C. The article I looked at analyzed the selectivity and reaction rate of the dehydration of 1-pentanol to DNPE using a gel-type resin at various temperatures and alcohol flow rates.

In the syntheses of aromatic esters and ethers, CsF-Celite has been found to be a very efficient, convenient and practical reagent. In fact, it is used for the coupling reactions of a number of aromatic and heteroaromatic phenols with alkyl, acyl or benzoyl halides.

Many other organic reactions have recently been catalyzed by CsF-Celite, such as the reactions to synthesize carboxylic esters, γ-lactones, N-alkylation of anilines, or carboxamides.

The above reaction is an example of a Williamson synthesis of an ether. It is one the earlier steps in the reaction mechanism resulting in the octaethylene glycol derivative of 1,1,1,3,5,5,5-heptamethyltrisiloxane. Such an initial Williamson synthesis reaction had to be carried out so that later steps in the reaction—that is, ones involving material types not readily accessible—could successfully yield the derivative product. The resultant glycol derivative is an example of a defined surfactant. This particular journal article focused on the correlation between surfactant constituents and the effect on properties such as spreading performance.
The Williamson synthesis involves an SN2 reaction in which a halogen, sulfonyl, or sulfate group is replaced by an alkoxide ion, which can itself be prepared by a reaction of the alcohol with an active metal such as sodium or its hydride (i.e. NaH). The resultant alkoxide salt then reacts with the alkyl halide (must be primary) to produce an ether via the SN2 mechanism.
Other examples of Williamson synthesis of ethers can be found in this same reaction mechanism used to produce the surfactant. 

This is one of the synthesis steps to produce tolterodine tartrate. The focus of the study was to find a cost-effective and impurity-free process to produce tolterodine tartrate. This compound is a muscle relaxant used to treat bladder disorders. Although ethers are inert to most reagents, a benzyl ether, like the one above, can be hydrogenated under mild conditions (H2/Raney/Ni/MeOH/25-30 C) to an alcohol. The phenyl group stays and the methylbenzene group leaves.