Abstract: A composite material highly suitable for use in over-current protection devices comprising a semi-crystalline polymer which has in its matrix finely dispersed carbon black material that has been chemically reacted with a grafting agent, and has the grafting agent covalently attached to the carbon black. The grafting agent includes a lipophilic portion or moiety that renders the carbon black linked to the grafting agent highly compatible with the polymer matrix. The auto thermal height (ATH) of the composite materials is significantly enhanced and a slight positive temperature coefficient is still observed with rising temperature after the transition temperature of the composite material has been reached.

Abstract: A chemical sensor utilizing a substrate and a fluoropolymer coating is disclosed. Transducers may be connected to the substrate to generate an alternating potential across the substrate, which in turn causes the substrate to resonate due to the converse piezoelectric effect. The polymer coating absorbs the analyte, thus changing the mass of the sensor, and accordingly changing its resonant frequency. The transducers detect this change in resonant frequency to indicate to the operator that the analyte is present. The use of amorphous copolymers of 2,2-bistrifluoromethyl-4,5-difluoro-1,3-dioxole (PDD), and tetrafluoroethylene (TFE) allows for improved sensitivity and responsiveness while also allowing for robust characteristics enabling the sensor to be used in a variety of environmental conditions.

Abstract: A polymeric material including a microporous matrix disposed in a multi-block polymer having a backbone of the general formula: [(A)n−(B)m−(X)l]p wherein: A is a first copolymerized monomer; B is a second copolymerized monomer; X is a third copolymerized monomer the same as or different from A; n and m are the same or different and are each an integer in the range of from 30 to 3000; is 0 or an integer in the range of from 30 to 3000; p is an integer in the range of from 1 to 100; wherein the microporous matrix is defined by reactive cleavage of at least a portion of a pendant moiety on B. The polymeric material is produced by a process which comprises cleavage of at least a portion of pendant moiety on B while leaving the backbone of the copolymer intact. This approach facilities production of a substantially uniform distribution of very small pores of substantially uniform dimension.

Abstract: An acoustic wave based-chemical sensor utilizing a crystal substrate and a coating of at least two blended materials is disclosed. The blended materials comprise a combination of (a) a high glass transition temperature polymer or a material of high melting point, and (b) a low glass transition temperature polymer or a material having a low melting point. Transducers are connected to the crystal substrate to generate an alternating potential across the crystal substrate, which in turn causes the crystal to resonate due to the converse piezoelectric effect. The blended coating absorbs the analyte, thus changing the mass of the chemical sensor, and accordingly changing its resonant frequency. The transducers detect this change in resonant frequency to indicate that the analyte is present.

Abstract: An acoustic wave based-chemical sensor containing a crystal substrate and a coating of small particulate matter is disclosed. The small particulate matter can be graphite particles. Transducers are connected to the crystal substrate to generate an alternating potential across the crystal substrate, which in turn causes the crystal to resonate due to the converse piezoelectric effect. The coating absorbs the analyte, thus changing the mass of the sensor, and accordingly changing its resonant frequency. The transducers detect this change in resonant frequency to indicate that the analyte is present. The use of small particulate matter results in a coating having a large surface area which facilitates mass uptake of large amounts of VOCs, improved acoustic properties even with relatively thick coatings, and a high operational temperature range.

Abstract: A process for producing an essentially monolayer coating of crosslinked polymer on a substrate, in which a block copolymer is introduced into a semi-solvent which solvates only one block of the copolymer, the resultant block copolymer semi-solution is contacted with a substrate, and the copolymer is then crosslinked.