Michael S. Silverstein

• Professor at Technion – Israel Institute of Technology

A polyHIPE-based substance-releasing system capable of releasably encapsulating a highly concentrated solution and/or a room temperature solid while minimizing or avoiding burst release from the closed-cell microstructure of an elastic polyHIPE.

Polysaccharides are abundant natural resources that are of interest for various biomedical applications. In addition to being biocompatible and biodegradable, these polymers can undergo a wide range of application-specific chemical modifications. Here, macroporous polymer monoliths based on four different polysaccharides (alginate, pectin, dextran,...

PolyHIPEs, macroporous polymers templated within high internal phase emulsions (HIPEs), emulsions with over 74% internal phase, are almost always crosslinked to prevent collapse during drying. Here, elastomeric poly(urethane urea) (PUU) polyHIPEs with highly interconnected open-cell structures were synthesized in water-in-oil (w/o) HIPEs. The ureth...

The ability of β-cyclodextrin (β-CD) to form a host–guest complex with relatively hydrophobic molecules such as bisphenol A (BPA), a common wastewater contaminant, has inspired the development of β-CD-containing polymers for adsorption applications. For the most part, these polymers are powders, which can limit their applicability. Here, low-densit...

Porous carbons are of interest for a wide range of advanced‐technology ‘green’ energy applications including fuel cells, hydrogen storage, supercapacitors and batteries. Functional groups, heteroatoms and a more accessible hierarchical porous structure would be advantageous for many of these applications. This paper describes the generation of carb...

PolyHIPEs, macroporous polymers synthesized within the external phases of high internal phase emulsions (HIPEs), have been developed for a wide range of applications (catalyst supports, tissue engineering, drug delivery) in which the leaching of traditional surfactants can become a significant liability. HIPEs can also be stabilized with relatively...

PolyHIPEs are porous, emulsion-templated polymers synthesized within high internal phase emulsions (HIPEs), concentrated emulsions usually containing over 74 % of a dispersed internal phase. PolyHIPEs are usually hydrophobic, crosslinked polymers synthesized within water-in-oil (w/o) HIPEs through free radical polymerization (FRP). There have only...

A typical description of interpenetrating polymer networks (IPN) can be surprisingly simple, systems that consist of two crosslinked polymers networks that are physically entangled but not chemically linked. That simplistic description, however, successfully encompasses a wide range of synthesis processes and macromolecular architectures that can i...

Cellulose is one of the most abundant resources in nature. Cellulose-based porous monoliths have been fabricated by direct drying of oil-in-water high internal phase emulsions (HIPEs) stabilized using either cellulose derivatives or surface-modified cellulose. The resulting cellulose-based porous polymers, however, were usually fragile, reflecting...

Porous polymers have been evolving continuously since the introduction of foam rubber in 1929. Today, pore diameters ranging from sub‐nanometre to millimetre can be generated controllably. Cutting‐edge porous polymers are now being applied at the forefront of critical problems with societal and environmental impact including advanced systems for bi...

Emulsion templating presently extends far beyond the original hydrophobic porous polymers that were synthesized within surfactant-stabilized water-in-oil high internal phase emulsions (HIPEs) by using free radical polymerization. This Perspective presents the extraordinary versatility of emulsion templating that has emerged with the growing numbers...

PolyHIPEs (PHs) are usually porous polymer monoliths templated within high internal phase emulsions (HIPEs), emulsions containing at least 74% dispersed internal phase, through free radical polymerization. Truly closed-cell PHs for encapsulating water, aqueous solutions, or inorganic salts have been synthesized within water-in-oil HIPEs through a j...

PolyHIPEs (PHs) are porous polymers that are typically templated within surfactant-stabilized high internal phase emulsions (HIPEs). Hydrogel PHs (HG-PHs) have exhibited potential as absorbents, adsorbents, release systems, and tissue engineering scaffolds. Recent work has shown that HG-PHs with highly temperature sensitive water uptakes could be p...

A series of highly porous zwitterionic hydrogel polyHIPEs (Z-HG-PHs) were synthesized within oil-in-water high internal phase emulsions (HIPEs) from N-(3-sulfopropyl)-N-(methacryloxyethyl)-N,N-dimethylammonium betaine and crosslinked with N,N'-methylenebisacrylamide. The Z-HG-PHs exhibited an anti-polyelectrolyte effect, with the uptake of aqueous...

A polyHIPE (PH) is a macroporous polymer synthesized within a high internal phase emulsion (HIPE). The high-porosity, highly interconnected, open-cell structures and the PH-swelling-driven void expansion mechanism have made PH systems of interest for liquid absorption. Usually, only hydrophobic liquids or only hydrophilic liquids are considered for...

Double-network (DN) hydrogels combine two very different polymer networks. Here, porous hydrogels with DN structures were successfully synthesized in two sequential free-radical polymerization steps. The first network was templated within a high internal phase emulsion (HIPE) to yield a hydrogel polyHIPE (HG-PH). The double network hydrogel polyHIP...

Double crosslinking can be used to significantly improve the mechanical properties of gels. Here, doubly-crosslinked hydrogel polyHIPEs (DC-PHs), which exhibited rapid water absorption, enhanced mechanical properties, and shape memory behaviour, were generated by forming metal coordination crosslinks within covalently crosslinked hydrogel polyHIPEs...

Emulsion-templated porous polymers (polyHIPEs) with highly interconnected voids that range from a few micrometers to hundreds of micrometers are typically synthesized within the external phases of high internal phase emulsions (HIPEs), emulsions containing more than 74% internal phase. Recent advances in emulsion-templated polymers include new deve...

A hierarchically porous carbon monolith with a density of 0.059 g cm‑3 (97 % porosity) was generated through the carbonization of an emulsion-templated monolith formed from a deep-eutectic polymer based on the polycondensation of 2,5-dihydroxy-1,4-benzoquinone with excess urea. The mechanical integrity and thermal stability of the monolith were suc...

Superabsorbent, mechanically robust, high-porosity hydrogels based on poly(2-acrylamido-2- methyl-propanesulfonic acid) (PAMPS) have been successfully synthesized by templating within high internal phase emulsions (HIPEs). These hydrogel polyHIPEs (HG-PHs) exhibited unusually high uptakes of water and of artificial urine through structure- and cros...

PolyHIPEs are highly porous, emulsion-templated polymer monoliths typically synthesized within water-in-oil (W/O) high internal phase emulsions (HIPEs). Biodegradable polyHIPEs are of great interest for industrial and biomedical applications. Recently, as much as 50 wt % biodegradable methacrylate-terminated polycaprolactone (PCL-MA) oligomer has b...

PolyHIPEs are porous polymers synthesized within high internal phase emulsions (HIPEs). This paper describes hydrogel-filled, shape-memory polyHIPEs (SMPHs) based upon a polyacrylate with crystallizable side-chains. These polyHIPEs had closed-cell-like voids with diameters ranging from 5 to 100 μm and a 200 nm thick hydrogel coating. The mechanical...

High porosity, hydrogel polyHIPE copolymers exhibited extraordinary, pH-responsive water uptakes, reaching 18.2 g g-1 at pH 10 for a hydroxyethyl methacrylate to methacrylic acid mass ratio of 1:1. Hydrogels, three-dimensional hydrophilic polymer network structures, can absorb many times their dry weight in water. PolyHIPEs are highly porous polyme...

Porous carbons with hierarchical porous structures that combine microporosity, mesoporosity, and macroporosity, should have more accessible porous infrastructures that would be advantageous for a range of "green" energy-storage applications. PolyHIPEs are porous polymers, templated within high internal phase emulsions (HIPEs), that can themselves b...

Polymeric foams and elastomer/hydrogel bicontinuous composite structures derived from high internal phase emulsions and possessing shape-memory characteristics are disclosed, as well as processes for forming the same and uses thereof in, for example, manufacturing of various articles.

Porous polymers with well-defined porosities and high specific surface areas in the form of monoliths, films, and beads are being used in a wide range of applications (reaction supports, separation membranes, tissue engineering scaffolds, controlled release matrices, responsive and smart materials) and are being used as templates for porous ceramic...

Sulfonated polymers are of interest for ion exchange resins, reaction supports, and membranes for separation, filtration, fuel cells, and electrochemical devices. Sulfonic groups have been introduced into polystyrene (PS) through exposure to sulfuric acid, and carbon nanotubes (CNTs) have been added to polymers to enhance proton conductivity withou...

Conditions to synthesize a degradable polymerized high internal phase emulsion (PolyHIPE) by a controlled radical polymerization (CRP) method, atom transfer radical polymerization (ATRP), have been developed for the first time. Activators generated by electron transfer (AGET) ATRP were used to copolymerize 2-ethylhexyl methacrylate (EHMA) and bis(2...

PolyHIPEs are porous emulsion-templated polymers synthesized within high internal phase emulsions (HIPEs). HIPEs are highly viscous, paste-like emulsions in which the major, “internal” phase, usually defined as constituting more than 74% of the volume, is dispersed as discrete droplets within the continuous, minor, “external” phase. The surge in po...

A series of well-defined poly(ethylene oxide) (PEO)-based star copolymers with controlled number of arms, compactness, and compositions were prepared by atom transfer radical polymerization using a simple “arm-first” method. Tuning the composition of the arms allowed these star polymers to stabilize either oil-in-water or water-in-oil emulsions. St...

Shape memory polymers (SMPs) change their shape under a stimulus (thermal, chemical, light) and return from an imposed temporary shape to their permanent, original shape. SMPs usually contain “permanent” domains that determine the permanent shape (chemical or physical crosslinks) and “reversible” domains that determine the temporary shape, usually...

The ability to encapsulate and store liquids within discrete, micrometer-scale containers is essential for living organisms and is used by water-storage cells to keep plants healthy, even during a prolonged drought. This paper describes the one-pot synthesis of liquid droplet elastomers (LDEs), a novel materials system with advantageous properties....

Sulfonated polymers are of interest as semipermeable ion-selective materials for membrane applications and as conductive materials for antistatic, electrode, and fuel cell applications. An innovative “one-pot” synthesis route was developed to produce relatively flexible systems containing a cross-linked polyacrylate elastomer within a continuous su...

In recent research, electrospun nanofibers (NFs) from polymer solutions containing metal salts were used to produce high-temperature superconducting ceramic (HTSC) NFs through pyrolysis. In this research, the production of phase separated nanostructures inside NFs spun from polymer solutions containing metal salts was investigated. The metal salts...

PolyHIPEs are porous polymers synthesized within high internal phase emulsions (HIPEs). Recent research has shown that the locus of conventional free radical initiation (at the oil-water interface or in the organic phase) can affect the polyHIPE's structure and properties. This paper is the first investigation of polyHIPE synthesis using activators...

This book gathers the various aspects of the porous polymer field into one volume. It not only presents a fundamental description of the field, but also describes the state of the art for such materials and provides a glimpse into the future. Emphasizing a different aspect of the ongoing research and development in porous polymers, the book is divi...

PolyHIPEs are emulsion-templated polymers synthesized within high internal phase emulsions (HIPEs). The miscibility of acrylonitrile (AN) with water has made it difficult to synthesize PAN-based polyHIPEs. This paper describes the successful synthesis of PAN-based polyHIPEs by crosslinking through copolymerization with divinylbenzene (DVB), by stab...

Water absorption is often poor in hydrophobic polyHIPEs, porous polymers synthesized within high internal phase emulsions (HIPEs). This paper describes bicontinuous polyHIPEs, the simultaneous polymerization of hydrophobic monomers (external phase) and hydrophilic monomers (internal phase). Integrating hydrogels within polyHIPEs extended the releas...

A large variety of porous polymers, generally known as polyHIPEs, have been synthesized using high internal phase emulsions (HIPEs) as templates for the porous structure. HIPEs are formed by mixing two immiscible liquids in the presence of an emulsifier, usually a surfactant, such that the internal phase content is more than 74 %. PolyHIPE are synt...

A polyHIPE is a highly porous polymer synthesized from monomers within the external phase of a high internal phase emulsion (HIPE). The large amount of difficult to remove surfactant needed for HIPE stabilization can affect the properties of the resulting polymer. A Pickering emulsion is a surfactant-free emulsion stabilized by solid particles that...

A polyHIPE is a highly porous, emulsion-templated polymer synthesized by polymerizing a monomer and a crosslinking comonomer in the continuous phase of a high-internal phase emulsion (HIPE). The synthesis of degradable polyHIPE could be of interest for biomedical applications such as tissue engineering scaffolds. In this research, a poly(ε-caprolac...

PolyHIPE are highly porous, emulsion-templated polymers typically synthesized via free-radical polymerization within a water-in-oil (W/O) high internal phase emulsion (HIPE) whose dispersed, aqueous phase occupies more than 74% of the volume. The synthesis of a polyHIPE containing biodegradable polymers is not straightforward because the presence o...

The production of hydrophilic porous emulsion-templated polyacrylate polyHIPE through hydrolysis polyHIPE was described. The hydrophobic polyHIPE, based on t-butyl acrylate (tBA), was synthesized within a water in oil (W/O) HIPE. The hydrolysis of tBA in a solution of trifluoroacetic acid (TFA) and dichloromethane (CH2Cl2) was used to produce carbo...

Highly porous, emulsion-templated polymers, polyHIPE, that are synthesized within high internal phase emulsions (HIPS) combine a fully interconnected open-pore structure with mechanical integrity and the ability to absorb relatively large amounts of liquid through capillary action. Biodegradable polyHIPE would be of interest for tissue engineering...

Polymerization in the external phase of a high internal phase emulsion (HIPE) yields an emulsion templated, porous polyHIPE. This work describes the synthesis of novel bicontinuous hydrogel–hydrophobic polymer systems through simultaneous polymerization and cross-linking reactions in the HIPE's external organic-phase (styrene or 2-ethylhexyl acryla...

Transmission electron microscopy (TEM) cross-section specimens of PMMA in contact with gold and Si were prepared by focused ion beam (FIB) and compared with plan-view PMMA specimens prepared by a dip-coating technique. The specimens were characterized by TEM and electron energy loss spectroscopy (EELS). In the cross-section specimens, the thin film...

A polyHIPE is a cross-linked, highly porous polymer from the polymerization of monomers and cross-linking comonomers in the external phase of a high internal phase emulsion (HIPE). Crystallizable polyHIPE were synthesized through the copolymerization of stearyl acrylate (A18) with ethylene glycol dimethacrylate (EGDMA). PolyHIPE synthesized with th...

A polyHIPE is a cross-linked, porous polymer synthesized through polymerization in the external phase of a high internal phase emulsion (HIPE). Crystalline polyHIPE polymers were synthesized through copolymerization of stearyl acrylate and divinylbenzene (DVB). Polymerizations initiated at the water/organic interface were compared to equivalent bul...

Highly porous elastomeric nanocomposites were successfully synthesized through copolymerization of 2-ethylhexyl acrylate (EHA), divinyl benzene (DVB), and up to 9 mol % of a polyhedral oligomeric silsesquioxane bearing one propylmethacryl group and seven cyclohexyl groups (MACH-POSS) within the external phase of high internal phase emulsions (HIPE)...

A versatile approach to the synthesis of YBCO (high temperature superconductor ceramics) nanofibers via electrospinning a polymer precursor solution is reported. The aqueous polymer precursor solution consists of poly(acrylic acid) (PAAc) and a mixture of yttrium nitrate, barium nitrate, and copper nitrate, henceforth termed (Y,Ba,Cu)–N. The conduc...

PolyHIPE are highly porous, open-pore, cross-linked polymers synthesized within high internal phase emulsions (HIPE). Biodegradable polycaprolactone (PCL) oligomers were incorporated into polyHIPE using two approaches. The first approach involved copolymerization with a vinyl-terminated PCL (PCL-VL). This approach yielded a typical polyHIPE structu...

The effects of plasma exposure (O 2 , Ar, H 2 , and CF 4 ) on the surface chemistries, surface energies, and dielectric constants, k , of two low‐ k SiCOH films (BD‐1 and BD‐2) and a methyl silsesquioxane (MSQ) control are described. Relatively non‐polar, low surface energy MSQ and BD‐2 exhibited significant changes when exposed to various plasmas:...

Hydrogels, such as those based on poly(2-hydroxyethyl methacrylate) (PHEMA), are hydrophilic three dimensional network structures that undergo extensive swelling in water. PolyHIPEs are highly porous, crosslinked polymers typically synthesized within high internal phase emulsions (HIPEs). This research describes materials with enhanced water absorp...

Poly(methyl methacrylate-b-ethylene oxide-b-methyl methacrylate) (PMMA–PEO–PMMA) triblock copolymers were synthesized using atom transfer radical polymerization (ATRP) and halogen exchange ATRP. PEO-based macroinitiators with molecular weight from Mn = 2000 to 35,800 g/mol were used to initiate the polymerization of MMA to obtain copolymers with mo...

Novel silsesquioxane-cross-linked porous nanocomposites with densities of around 1.5 × 102 kg/m3 were synthesized within high internal phase emulsions (HIPE) in which 2-ethylhexyl acrylate (EHA) was cross-linked and reinforced with vinyl silsesquioxane (VSQ). The molecular structure, porous structure, thermal properties, mechanical properties, and...

‘PolyHIPE’ are porous polymers from the polymerization of monomers and crosslinking co-monomers in the continuous phase of high internal phase emulsions (HIPE). Elastomeric polyHIPE have been reinforced through the synthesis of nanocomposites using several different routes including the addition of co-monomers such as vinyltrialkoxysilane, polyhedr...

The mechanical properties and thermal stability of polymers can be enhanced through the formation of nanocomposites. Nanocomposites consisting of hybrid copolymers of methacrylcyclohexyl polyhedral oligomeric silsesquioxane (POSS-1) and methyl methacrylate (MMA) with up to 92 wt % (51 mol %) POSS-1 and with superior thermal properties were synthesi...

Novel porous nanocomposites with uniquely interconnected silsesquioxane (SSQ)-organic networks were synthesized within high internal phase emulsions (HIPE). These nanocomposite polyHIPE, with densities of around 0.13 g/cm 3 , were synthesized from 2-ethylhexyl acrylate (EHA), divinylbenzene (DVB, organic cross-linker), and either methylsilsesquioxa...

PolyHIPE are cross-linked, highly interconnected porous polymers with unique multiscale, open-pore structures that are based on high internal phase emulsions (HIPE). This work is the first to describe crystallinity in polyHIPE. This novel crystallinity was achieved by using monomers with n-alkyl side chains (acrylates and methacrylates). Such cryst...

Polymers that form a complex with metal ions from nitrate salts can be used to prepare precursors for the production of high temperature superconductor (HTSC) ceramics that can be processed using advantageous polymer processing techniques and then pyrolyzed. This paper describes the production of HTSC from a precursor based on m-cresol formaldehyde...

Low molecular weight triblock copolymers (TBCs) with poly(styrene-co-acrylonitrile) (SAN) end-blocks and poly(ethylene oxide) (PEO), poly(propylene oxide) (PPO) or polycaprolactone (PCL) mid-blocks were synthesized using atom transfer radical polymerization (ATRP). The influence of molecular weight, composition (mid-block mole fraction), and intera...

Nanometer scale porosity is introduced into low-dielectric constant (“low-k”) materials to achieve permittivities less than 2.0. X-ray reflectivity (XRR) and small-angle neutron scattering (SANS) are complementary methods for characterizing pore size distributions (PSD). In this paper, the PSD in a polyphenylene low-k material is characterized via...

Typical polyHIPE (porous polymers from high internal phase emulsions) have a cellular structure with volume fractions from 0.2 to 0.04, cell diameters from 15 to 25 μm and intercellular pore diameters from 0.5 to 10 μm. Unique interpenetrating polymer networks synthesized within the polyHIPE exhibited enhanced mechanical properties and an extended...

The use of polymers containing metal salts as ceramic high-temperature superconductor (HTSC) precursors may provide a relatively simple and rapid method for producing materials that can take advantage of advanced polymer processing and then be pyrolyzed to HTSCs. The mechanisms of thermal degradation in these precursors, which have not been charact...

Nanometer-scale porosity is being introduced into low-k dielectrics in an attempt to achieve inter-level metal insulators with permittivities less than 2.0. It has proven extremely difficult to describe pore formation and to characterize the porous structure. This work investigates pore formation in a polyphenylene low-k dielectric based on pyrolys...

Highly porous, open-cell polymers [poly(HIPE)] were prepared by polymerizing the monomers in the continuous phase (∼ 10%) of high internal phase emulsions (HIPE). This paper discusses using poly(HIPE) to remove bromoform from an aqueous solution through sorption, a combination of adsorption and absorption. The crosslinked polystyrene (xPS) and cros...

A high temperature superconductor (HTSC) precursor containing a polymer and metal nitrates may be processed with relative ease before pyrolysis. This article focuses on the thermal decomposition of poly(acrylic acid) (PAAc) containing copper nitrate (CueN) as a first step in the study of an HTSC precursor containing copper, barium and yttrium nitra...

Modification of porous suspension-type polyvinyl chloride (PVC) particles was studied. Two approaches were described, namely, polymerization in the solid and in the molten state. The two approaches result in different blend properties, making them suitable for different applications. The first approach includes modification in the solid state where...

The pyrolysis of polymers containing metal nitrates may provide a rela- tively simple, rapid, and advantageous method of producing high-temperature super- conductors (HTSCs). The advantage lies in the ability to use conventional polymer processing or microlithographic patterning before pyrolysis. A copolymer of acryloni- trile and vinyl acetate (P(...

Polymers containing metal-nitrates have been proposed as advantageous precursors for high temperature superconductors such as yttrium-barium-copper-oxide (YBCO). The advantage lies in using conventional polymer processing such as fiber spinning or microlithography before pyrolysis. This research investigated complex formation and degradation in pol...

This paper presents the results of thermal analysis (TA) with simultaneous mass spectroscopy and FTIR investigations of Y–Ba–Cu-polymer and Bi–Sr–Ca–Cu-polymer precursors where the polymers are either novolak or poly(acrylic acid) (PAA). It is shown that the thermal degradation behaviour of precursors influences the quality of high temperature supe...

Modified porous PVC particles are studied as absorbents of o-dichlorobenzene (DCB), from water. The modified particles were produced by an in-situ stabilizer-free polymerization/crosslinking of a monomer/crosslinker/peroxide solution absorbed within commercial porous suspension-type PVC particles. The modifying monomers used include styrene with di...

Specular x-ray reflectivity and small angle neutron scattering were used to characterize changes in the porosity, pore size and pore size distribution on processing a polymeric low-k material filled with 21.6 volume percent of a deuterated porogen with an average radius of 56 Å. Processing yielded a decrease in porosity to about 11 %, an increase i...

The synthesis and characterization of novel polymerized high internal-phase emulsions (polyHIPE) materials are described. Homogeneous, highly porous, low-density, open-cell crosslinked copolymers were prepared by polymerizing the continuous phase of HIPE containing styrene and varying amounts of 2-ethylhexyl methacrylate. The glass transition tempe...

The present study describes modification of porous PVC particles by polymerization of a monomer/crosslinker/peroxide solution absorbed within the PVC particles. The modifying crosslinked polymers include butyl acrylate (BA) crosslinked with ethylene glycol dimethacrylate (EGDMA) and ethylhexyl acrylate (EHA) crosslinked with EGDMA. The monomer solu...

Polythiophene (PTh) is of interest for transistors, light emitting diodes and sensors. Plasma polymerization is a solvent-free, room temperature process that can be used to rapidly deposit thin polymer films onto a wide variety of substrates. This paper describes the synthesis of plasma polymerized thiophene (PPTh) and the dependence of molecular s...

The demand for increased signal transmission speed and device density in the next generation of multilevel integrated circuits (ICs) has placed stringent demands on materials performance for such applications as the line-to-line capacitance of interlayer dielectrics (ILD).1 The ‘National Technology Roadmap for Semiconductors (NTRS) -Technology Need...

High internal phase emulsion (HIPE) copolymer and interpenetrating network foams were prepared from 2-ethylhexyl acrylate (EHA), styrene (S) and divinylbenzene (DVB) using a unique process. The morphologies, thermal properties and dynamic and static mechanical properties of these foams were investigated. The glass transition temperatures and dampin...

The transport properties of a unique family of silane-modified poly(vinyl chloride) (PVC) pervaporation membranes for the separation of halogenated hydrocarbons from water were investigated. The PVC was modified by using a vinyl silane to improve its resistance to attack by halogenated hydrocarbons and to increase the flux. Two preparation routes w...

Hybrid foams, which combine an inorganic polysilsesquioxane network with an organic polystyrene network, were successfully synthesized using high internal phase emulsions (HIPE). Methacryloxypropyltrimethoxysilane (MPS) was copolymerized radically with styrene (S) and divinylbenzene (DVB) in the organic phase of the emulsion. The hydrolytic condens...

The need for increased signal transmission speed and device density in the next generation of multilevel integrated circuits (ICs) places stringent demands on materials performance. There is a requirement for interlayer dielectrics with permittivities under 3 (low κ dielectrics) that have compatibility with copper and copper processing. Plasma poly...