The present invention relates to porous silica particles partially functionalized with long hydrocarbon chains loaded with a fungicidal agent having the ability to release the fungicidal agent in a targeted and selective manner at the site of infection, thus avoiding the unnecessary release of fungicidal agents on the plant product and into the environment. The invention also relates to a process for preparing these particles, to a system for the controlled and targeted release of fungicide based on the same and to the use thereof for fungicide treatments.

Provided is a method for efficiently producing an oxadisilacyclopentane compound at a high yield, comprising reacting an azadisilacyclopentane compound with water, the azadisilacyclopentane compound having the following general formula (1):

##STR00001## [R.sup.1 to R.sup.4 are each independently an unsubstituted monovalent hydrocarbon group having 1 to 4 carbon atoms, and R.sup.5 is a hydrogen atom, a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, or a group having the following general formula (2):

##STR00002## (R.sup.1 to R.sup.4 are as defined above, m is an integer of 0 to 5, n is an integer of 1 to 5, and a broken line donates a valence bond.) the oxadisilacyclopentane compound having the following general formula (3):

##STR00003## (R.sup.1 to R.sup.4 are as defined above.).]

A cohydrolysis method is used to prepare an asymmetric (meth)acrylate-functional diorganosiloxane from a (meth)acryl-functional silane, a diorganohydridohalosilane, and water.

The present invention provides a process for depolymerizing waste silicones to afford siloxane cycles, wherein the process comprises a first step of reacting the waste silicone with at least one alcohol and at least one alkali metal alkoxide without removing any potentially occurring water from the reaction mixture, subsequently neutralizing the reaction mixture, removing the solid constituents and then distillatively removing the optionally previously added solvent and excess alcohol and subsequently heating the obtained alkoxysiloxane with at least one fatty alcohol and at least one alkali metal alkoxide with mixing and distillatively removing the siloxane cycles formed.

The present disclosure provides an aerogel precursor including an alkoxydisiloxane-based prepolymer and having a functional group derived from a hydrophobic sol-gel forming agent of the following Chemical Formula 1 on a surface thereof, and therefore, capable of enhancing high temperature thermal stability of an aerogel providing hydrophobic pores having uniform pore size distribution when preparing an aerogel, and an aerogel prepared using the same:

##STR00001##

(in Chemical Formula 1, M, R, R.sup.1 to R.sup.4 are the same as defined in the specification.)

A method is useful for forming a product including a cyclic siloxane compound. The method includes combining an organodihalosilane and a transition metal on cerium (IV) oxide catalyst, in a reactor at a temperature of to form the product.

A method for preparation and polymerization of siloxane monomers of Formula I is presented. The synthesis includes the selective reaction between silanol containing unit and alkoxy containing units in the presence of basic catalyst. The siloxane monomers of the invention can be used for preparation of siloxane polymers with good flexibility and cracking threshold, and functional sites, useful for applications requiring low metal content in semiconductor industry.

A branched organosilicon compound is provided having the general formula: (R.sup.1).sub.3X[SiR.sub.20].sub.nSiR.sub.2R.sup.3. In the formula: each R is independently a substituted or unsubstituted hydrocarbyl group; each R.sup.1 is selected from R and OSi(R.sup.4).sub.3, with the proviso that at least one R.sup.1 is OSi(R.sup.4).sub.3; each R.sup.4 is selected from R, OSi(R.sup.5).sub.3, and [OSiR.sub.2].sub.mOSiR.sub.3; each R5 is selected from R, OSi(R.sup.6).sub.3, and [OSiR.sub.2].sub.mOSiR.sub.3; each R.sup.6 is selected from R and [OSiR.sub.2].sub.mOSiR.sub.3; with the proviso that at least one of R.sup.4, R.sup.5 and R.sup.6 is [OSiR.sub.2].sub.mOSiR.sub.3; 0m100; X is a divalent linking group; 1n10; and R.sup.3 has the general -D-O.sub.p(C.sub.qH.sub.2qO).sub.rR.sup.8. In R.sup.3, D is a divalent hydrocarbon linking group, subscript p is 0 or 1, subscript q is independently selected from 2 to 4 in each moiety indicated by subscript r, subscript r is from 1 to 500, and R.sup.8 is selected from substituted or unsubstituted hydrocarbyl groups and H.

The present invention describes branched and functionalized siloxanes and methods for making such compounds. The compounds have a variety of uses. One preferred application is as novel planarizing material for lithogaphy, in which case functionalized branched siloxane, such as an epoxy-modified branched siloxane is particularly useful.

Provided is a method of preparing a silylative-reduced N-heterocyclic compound by reducing an N-heteraromatic compound including a sp.sup.2 hybridized nitrogen atom while simultaneously introducing a silyl group into a beta-position with respect to a nitrogen atom of the N-heteroaromatic compound, using a silane compound, in the presence of an organoboron catalyst.