Organic molecules and semiconductors have been proposed as active part of a large variety of nonvolatile memory devices, including resistors, diodes and transistors. In this review, we focus on electrically reprogrammable nonvolatile memories. We classify several possible devices according to their operation principle and critically review the role of the π-conjugated materials in the device operation. We propose specifications for applications for organic nonvolatile memory and review the state of the art with respect to these target specifications. Conclusions are drawn regarding further work on materials and device architectures.

Polymer and Organic Nonvolatile Memory Devices

Poly(ethylene furanoate) (PEF), the furan-derived analogue to poly(ethylene terephthalate) (PET), can provide a fully biosourced alternative to PET with greatly improved barrier properties and attractive thermal and mechanical properties. The improved barrier for PEF compared to PET is unexpected due to the higher free volume of PEF vs PET. Segmental motions related to penetrant diffusion in both polyesters were studied using dynamic mechanical analysis, 13C–CP/MAS solid-state NMR variable contact-time experiments, and centerband-only detection of exchange (CODEX) measurements. Unlike the active phenyl ring-flipping mechanism in PET, furan ring-flipping is greatly suppressed, thereby reducing β relaxation motions and diffusion in PEF due to the energy penalty associated with the nonlinear axis of ring rotation and ring polarity. Preliminary work also shows similar oxygen solubilities for PEF and PET, thereby proving that the drastic permeability reduction results from a decrease in diffusion coefficient c...

Chain Mobility, Thermal, and Mechanical Properties of Poly(ethylene furanoate) Compared to Poly(ethylene terephthalate)

Morphology, thermal relaxations and mechanical properties of layered silicate nanocomposites based upon high-functionality epoxy resins

We present chain structure, phase morphology, and toughness relationships in thermoplastic polymers and polymer/rubber blends. In neat polymers, molecular aspects of craze/yield behavior are controlled by two chain parameters: entanglement density ν e and characteristic ratio C ∞ . The crazing stress is proportional to ν e 1/2 , and the yield stress is proportional to C ∞ . The dispersed rubber toughens a polymer/rubber blend mainly by promoting energy dissipation of the matrix. The toughening efficiency correlates with the rubber phase morphology and the chain structure of the matrix

Chain structure, phase morphology, and toughness relationships in polymers and blends

The thermodynamic and dynamic properties of a partially deuterated poly(ethylene‐propylene)–poly(ethylethylene)(PEP–PEE) diblock copolymer containing 55% by volume PEP were characterized above and below the order–disorder transition (ODT) by small‐angle neutron scattering (SANS) and rheological measurements, respectively. Both experimental techniques produced unambiguous evidence of composition fluctuations well above TODT(T−TODT≲50 °C) in the disordered state, which increase in magnitude as the weak first‐order transition is approached. Based on the SANS results, which are nearly predicted by a recent fluctuation theory, we conclude that the (equilibrium) instantaneous morphology in the disordered state closely resembles a spinodally decomposed binary mixture. Below TODT, long‐range order can be obtained by the application of a shear field as evidenced by the resulting highly anisotropic (one‐dimensional) SANS pattern. As the ODT is approached in the shear‐oriented ordered state, an isotropic scattering ...

Fluctuation effects in a symmetric diblock copolymer near the order–disorder transition

Secondary relaxation processes in polyethylene terephthalate–additive blends: 2. Dynamic mechanical and dielectric investigations

Crystallization of poly(vinylidene fluoride)-poly(methyl methacrylate) blends: analysis of the molecular parameters controlling the nature of poly(vinylidene fluoride) crystalline phase

Fourier-transform infra-red dichroism study of molecular orientation in synthetic high cis-1,4-polyisoprene and in natural rubber

Compatible blends of polystyreneand poly(vinyl methyl ether) have been studied by high-resolution solid-state 13 C NMR. Line widths and spin-lattice relaxation times in the rotating frame have been measured for different resonances as a function of both temperature and blend composition. Results thus obtained have shown the existence of local chain motions with different frequencies and temperature dependences for the two polymers. By varying the blend composition, it has been possible to investigate the influence of intermolecular on the local chain dynamics of both components

Lucien Monnerie

Papers

Secondary relaxation processes in polyethylene terephthalate–additive blends: 2. Dynamic mechanical and dielectric investigations

Crystallization of poly(vinylidene fluoride)-poly(methyl methacrylate) blends: analysis of the molecular parameters controlling the nature of poly(vinylidene fluoride) crystalline phase

Fourier-transform infra-red dichroism study of molecular orientation in synthetic high cis-1,4-polyisoprene and in natural rubber

Carbon-13 NMR investigation of local dynamics in compatible polymer blends

Secondary relaxation processes in polyethylene terephthalate-additive blends: 1. N.m.r. investigation