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The award-winning Phase Change Matters blog tracks the latest news and research on phase change materials and thermal energy storage. E-mail tips and comments to Ben Welter, communications director at Entropy Solutions. Follow the blog on Twitter at @PureTemp. Subscribe to the weekly PCM newsletter. Or join the discussion on LinkedIn.

Two Entropy advisors, Dr. Mohammed Farid and Lucas B. Hyman, are pleased to take your questions about PCMs and thermal energy storage. Send your questions to We'll select the best and post the answers here each week.




Patent application: Immersion cooling systems and methods

Ben Welter - Wednesday, October 11, 2017

U.S. patent application 20170290205 (applicant Hamilton Sundstrand Corp., Charlotte, N.C.)

"An electronics cooling arrangement includes a housing, an electronic device disposed within the housing, and a solid-liquid phase change material disposed within the housing and is in thermal communication with the electronic device to absorb heat generated by the electronic device. A method of cooling an electronic device and a vehicular electronics cooling system are also described."

Patent application: Controlled release microcapsules

Ben Welter - Wednesday, October 11, 2017

U.S. patent application 20170281985 (applicant Encapsys LLC, Appleton, Wis.):

"A method of forming microcapsules having improved physical properties and release control as well as the microcapsules formed by the process wherein the capsule wall is formed by the concurrent polymerization of monomers, oligomer and/or prepolymers on the inside of the capsule wall and different monomers, oligomers and/or prepolymers on the exterior of the capsule wall as it forms. ... Microcapsules containing phase change materials according to the present invention are prepared using a process with a two-part water phase and a single core phase."

Patent application: Micro environmental control system

Ben Welter - Monday, October 02, 2017

U.S. patent application 20170276408 (applicant Hussein Ezzat Khalifa, Manlius, N.Y.):

"A micro environmental control system that can remove or add 30W from or to the near range personal microenvironment of a user. For cooling, the μX uses a micro vapor compression system during the un-occupied period to freeze a phase-change-material in a thermal storage module. A fan then moves air over the phase-change-material to deliver cooled air. Heating is delivered by a small electric heater integrated into a condensing unit. The resulting system is inexpensive to build and uses a limited amount of energy."

Patent application: Evaporator and refrigerator using the evaporator

Ben Welter - Monday, October 02, 2017

U.S. patent application 20170276419 (applicant Samsung Electronics Co. Ltd., Gyeonggi-do, Republic of Korea):

"Disclosed are an evaporator, a refrigerator using the evaporator, and a method for controlling the refrigerator. The evaporator includes a refrigerant evaporation unit in which a flow passage where a refrigerant evaporates is formed, and a phase change material (PCM) accommodation unit that is coupled to the refrigerant evaporation unit and accommodates the PCM whose phase is changed according to latent heat absorbed by the refrigerant, wherein the PCM is brought into direct contact with an outer surface of the refrigerant evaporation unit inside the PCM accommodation unit."

Patent application: Breathable product for protective mass transportation and cold chain applications

Ben Welter - Monday, September 25, 2017

U.S. patent application 20170266609 (applicant E.I. DuPont De Nemours and Co., Wilmington, Del.):

"The present invention concerns a breathable product for protective mass transportation and cold chain applications, in particular a reflective sheet for covering temperature sensitive products the reflective sheet having at least a first layer made of a highly reflective moisture vapor permeable substrate having an outer side and an inner side, wherein said inner side comprises in addition at least a metal layer deposited by a PVD process to provide a thermal insulation through high reflection low convection while providing controlled moisture vapor permeability. ... The honeycomb structural element provides some additional thermal insulation because the spaces inside are filled with air, but these spaces may also be filled with a phase change material such as a wax, which will absorb and liberate additional heat during melting and freezing when the temperature distribution within the layers is favorable and the presence of the phase change material is not detrimental to the protected goods."

Patent application: Air-conditioning system for a machine

Ben Welter - Monday, September 25, 2017

U.S. patent application 20170267066 (applicant Caterpillar Inc., Peoria, Ill.):

"An air-conditioning system including a primary circuit and a secondary circuit is provided. The primary circuit includes a flow of refrigerant, an evaporator and a chiller configured to exchange heat between a coolant and the refrigerant. The secondary circuit includes a heat exchanger in fluid communication with the chiller to receive the coolant. The heat exchanger includes a phase change material in heat exchange relationship with the coolant, such that the coolant exchanges heat with the phase change material to store thermal energy in the phase change material. The air-conditioning system is implemented in a machine in which during an idle-off state, the stored energy in the heat exchanger is discharged to provide an air-conditioning effect."

Patent application: Enhanced metal-metal-matrix composite weapon barrels

Ben Welter - Tuesday, September 19, 2017

U.S. patent application 20170261280 (applicant Sapphire Defense Group LLC, Easley, S.C.):

"Weapon barrels are disclosed which offer improved thermal performance and rigidity with no, minimal or negative weight increase. In general the barrel comprises a barrel core surrounded by a lightweight, thermally conductive sleeve made from metal-matrix composite (MMC) materials, also referred to as metal-matrix material. The increased diameter of the sleeve improves the barrel's stiffness and the sleeve's thermal conductivity and distributes the heat more evenly along the barrel. ... Hot spots may be reduced and more surface area can contribute to heat dissipation. The increased diameter also allows integration of phase changing and/or vibration dampening materials, which further enhance performance."

Patent application: Temperature-stabilized culture incubator

Ben Welter - Tuesday, September 19, 2017

U.S. patent application 20170260492 (applicant Tokitae LLC, Bellevue, Wash.):

"Described embodiments include a culture incubator, method, and sensor circuit. A culture incubator includes an accessible incubation compartment configured to contain a culture item at a specified incubation temperature; a phase change material having a phase transition temperature over the specified incubation temperature; and a heat transfer element in thermal communication with the phase change material and configured to transfer heat to the phase change material. A sensor circuit is configured to acquire data indicative of a phase composition state of the phase change material. A manager circuit is configured to determine a difference between the phase composition state and a target phase composition state for the phase change material. A controller circuit is configured to transfer heat to the phase change material in an amount estimated to change the phase composition state of the phase change material to the target phase composition state."

Patent application: Product transport container

Ben Welter - Wednesday, September 13, 2017

U.S. patent application 20170253409 (applicant Phase Change Energy Solutions Inc., Asheboro, N.C.):

PCES patent drawing"Product transport containers are disclosed. Such containers can provide one or more advantages compared to existing containers. For example, product transport containers described herein can maintain a product at a desired temperature for an extended period of time, including without the use of an active heating or cooling component. Such product transport containers described herein may also provide improved breathability, thermal insulation, and/or mechanical strength or dimensional stability. Such containers can include a plurality of walls defining an interior volume and a selectively openable side permitting movement of the product into and out of the interior volume of the container. The walls can be formed from a thermoformed non-woven fabric."

Patent application: TES systems comprising encapsulated PCMs and a neutralizing agent

Ben Welter - Wednesday, September 13, 2017

U.S. patent application 20170254601 (applicant Entropy Solutions LLC, Plymouth, Minn.):

"Provided are Thermal Energy Storage (TES) systems comprising Phase Change Material (PCMs) compositions for thermal management in different applications such as building, automotive, and industrial applications. Provided are TES systems comprising encapsulated PCMs and a heat transfer medium comprising a neutralizing agent and/or an ion exchange resin capable of neutralizing the acidic or basic PCM contained in the capsules, should the PCM permeate the walls of the capsules or otherwise be released into the surrounding heat transfer medium."