The present invention relates to a process for the preparation of a hydrogel and to a hydrogel obtainable by said process. The present invention further relates to a process for the preparation of a hydrogel-spacer conjugate, to a hydrogel-spacer conjugate obtainable by said process, to a process for the preparation of a carrier-linked prodrug and to carrier-linked prodrugs obtainable by said process, in particular to carrier-linked prodrugs that provide for a controlled or sustained release of a drug from a carrier. In addition, the invention relates to the use of the hydrogel for the preparation of a carrier-linked prodrug.

In some aspects, the present disclosure pertains to multi-arm polymers that comprise a core, a plurality of polymer segments having a first end that is covalently attached to the core and a second end comprising a moiety that comprises a reactive group, wherein the polymer segments comprise one or more free-radical-polymerizable monomers. In some aspects, systems are provided that comprise a first composition comprising such a multi-arm polymer and a second composition comprising a multifunctional compound that comprises functional groups that are reactive with the reactive groups of the multi-arm polymer. In some aspects, systems are provided that comprise crosslinked reaction products of such a multi-arm polymer and such a multifunctional compound.

The present disclosure provides a polymer comprising a derivative of chitosan, wherein the derivative is zwitterionic, as well as methods of using the polymer. In addition, the present disclosure provides a nanoparticle structure comprising a derivative of chitosan and a dendrimer, as well as methods of utilizing the nanoparticle structure.

Aerogel compositions, methods for preparing the aerogel compositions, articles of manufacture that include or are made from the aerogel compositions are described and uses thereof. The aerogels include a branched polyimide matrix with little to no crosslinked polymers.

Solid polymer electrolyte and compound used for thereof are disclosed. The compound has a dendritic macromolecule and a cationic metal. The solid polymer electrolyte has increased ion conductivity even if the electrolyte is used at low temperature. Said solid polymer electrolyte is useful for a secondary battery.

The present disclosure provides a series of new and improved porous polyamide aerogels derived from multifunctional aromatics that combine the high mechanical strength of aramids with the pore structure of aerogels. The polyamide aerogels have a hyperbranched structure, relatively low density, high porosity and may be derived from functionalized monomers having more aromatic groups than functional groups. The present disclosure also provides a new method for producing the porous polyamide aerogels by polymerizing an aromatic multifunctional carboxylic acid or a ferrocene multifunctional carboxylic acid with a polyfunctional aromatic isocyanate at moderate reaction conditions followed by drying with liquid CO.sub.2. Also disclosed are various methods of use of these polyamide aerogels in a variety of applications, particularly in the generation of various precious metal catalysts. Thus, monolithic nanoporous carbon-supported Fe, Au, Pt, Pd, Co, Ni, Ru, and Rh catalysts are disclosed herein, which are derived by pyrolysis and transmetalation via galvanic replacement of ferrocene-based polyamide aerogels.

An aerogel that includes an open-cell structure and a polymer matrix is disclosed. The polymer matrix can include a branched polyimide polymer having a degree of branching of at least 0.5. The polymer matrix can contain less than 5% by weight of crosslinked polymers.

An aerogel that includes an open-cell structure and a polymer matrix that includes a polyimide polymer is disclosed. The polymer matrix can contain less than 5% by weight of crosslinked polymers.

The present invention generally relates to the field of conformance control in oil fields, particularly to a re-crosslinkable preformed particle gel system, and composition thereof. The composition of the re-crosslinkable preformed particle gel system contains monomers, crosslinkers, a polymer matrix, and additives. Components in the composition for re-crosslinkable preformed particle gel in the present invention have excellent compatibility with each other, and the obtained gel has excellent long term high-temperature resistance property. Different from prior products, in the re-crosslinkable preformed particle gel compositions according to embodiments of the present invention, the components that are used to re-crosslink the particle gels may be grafted on the polymer chain and will act as initiator or secondary crosslinker in different conditions. During particle injection process, all compositions would move together, thereby avoiding chromatographic problems typical of prior products.