This invention is in the field of surface modification. In particular, the invention relates to the surface modification of microfluidic devices to alter surface hydrophobicity characteristics.

A process for forming covalently cross-linked macromolecular networks, comprising reacting a compound of Formula (I), defined as R.sub.1-L-XR.sub.3, with a compound of Formula (II), defined as HZ-R.sub.2, to form a macromolecular compound of Formula (III), defined as R.sub.1-L-Y, wherein R.sub.1 represents a macromolecular polymer backbone, L represents an aryl or arylalkyl, R.sub.2 independently represents an optionally substituted branched or linear C.sub.1-C.sub.10 alkane, a C.sub.2-C.sub.10 alkene, a C.sub.2-C.sub.10 alkyne, wherein the optional substituent is a second HZ-moiety or a carboxylic ester moiety, R.sub.3 represents CF.sub.3, H or C.sub.1-C.sub.10 alkane, X represents C(O), C(O)C(CH.sub.2) or C(CH.sub.2)C(O), Y represents C(OH)(R.sub.3)ZR.sub.2, C(O)CH(R.sub.3)CH.sub.2ZR.sub.2 or CH(C(O)R.sub.3)CH.sub.2ZR.sub.2; and Z represents S or NH. A covalently connected adaptable network formed by the process is also described.

This invention is in the field of surface modification. In particular, the invention relates to the surface modification of microfluidic devices to alter surface hydrophobicity characteristics.

A foamable composition includes a semi-crystalline polyolefin having a crystallinity of at least 50% and a poly(sulfonyl azide) of at least 500 ppm based on the total weight of the foamable composition. The foamable composition has a melt strength of at least 20 cN, a melt drawability of at least 100 mm/s, flexural modulus is greater than about 240,000 psi. Such a composition can be used to make a low density foam having a density in the range from 0.005 g/cm.sup.3 to 0.6 g/cm.sup.3. A resulting foam or a fabricated article, the methods of the composition and the foam are also provided.

A propylene-based polymer composition is characterized by a melt strength at 190 C. of at least 20 cN, a melt drawability at 190 C. of at least 100 mm/s, and a flexural modulus at room temperature of at least 240,000 psi. The propylene-based polymer composition includes a propylene-based polymer resin having a crystallinity of at least 50% coupled with a poly(sulfonyl azide).

Methods of forming polymer layers on polymer surfaces using surface initiated atom-transfer radical-polymerization (ATRP) are described. The method can include functionalization steps prior to performing surface initiated ATRP, such as hydroxylation steps and/or halogenation steps. The hydroxylation step can be carried out in a solution including potassium persulfate, ammonium persulfate, or lithium hydroxide. The halogenation step can also be carried out in a solution. The methods described herein can be performed on bundles of hollow polymer fibers, including bundles of hollow polymer fibers mounted in a module.

A method of desulfurizing sulfur-crosslinked rubber includes adding a radical precursor that generates a radical active species that acts on a sulfur bond in the sulfur-crosslinked rubber and cleaves the sulfur bond and a radical initiator for generating a radical for converting the radical precursor into the radical active species to the sulfur-crosslinked rubber and performing heating.

Methods of forming polymer layers on polymer surfaces using surface initiated atom-transfer radical-polymerization (ATRP) are described. The method can include functionalization steps prior to performing surface initiated ATRP, such as hydroxylation steps and/or halogenation steps. The hydroxylation step can be carried out in a solution including potassium persulfate, ammonium persulfate, or lithium hydroxide. The halogenation step can also be carried out in a solution. The methods described herein can be performed on bundles of hollow polymer fibers, including bundles of hollow polymer fibers mounted in a module.

A cured blend of a butyl rubber ionomer, at least one elastomer co-curable with the butyl rubber ionomer and a filler has improved physical and/or dynamic properties, most notably improvements in one or more of green strength, flex fatigue, adhesion and tear strength.

A polymer electrolyte membrane fuel cell that includes a positive electrode, a negative electrode, a polyelectrolyte membrane and a solution of reduced graphene oxide and/or graphene oxide functionalized with metallized nanoparticles. The electrodes are coated with a polymer and the polyelectrolyte membrane has a hydrophobic exterior surface that is subjected to ultraviolet/ozone (UV/O.sub.3) exposure, which changes the hydrophobic, exterior surface to a hydrophilic exterior surface. The polyelectrolyte membrane is disposed between the positive electrode and the negative electrode and can include a sulfonated tetrafluoroethylene based fluoropolymer-copolymer. The solution forms a coating on the hydrophilic exterior surface of the polymer electrolyte membrane and the positive and negative electrodes. The positive and negative electrodes can be coated with a polymer, preferably polytetrafluoroethylene (PTFE) that can be subjected to ultraviolet/ozone (UV/O.sub.3) exposure. The metallized nanoparticles increase the efficiency of the fuel cell by at least 50% when the feed gas includes at least 1000 ppm carbon monoxide.