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Updated: Feb 24, 2026

Self-assembling Morphologies Obtained from Helical Polycarbodiimide Copolymers and Their Triazole Derivatives
Published on: February 7, 2017
Different Steric-Twist-Induced Ternary Memory Characteristics in Nonconjugated Copolymers with Pendant Naphthalene
Ming Wang1, Zhuang Li1, Hua Li1
1College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou, 215123, P. R. China.
Abstract:
Herein, novel random copolymers PMNN and PMNB were designed and synthesized, and the memory devices Al/PMNN and PMNB/ITO both exhibited ternary memory performance. The switching voltages of the OFF-ON1 and ON1-ON2 transitions for both memory devices are around -2.0 and -3.5 V, respectively, and the ON1/OFF, ON2/ON1 current ratios are both up to 103 . The observed tristable electrical conductivity switching could be attributed to field-induced conformational ordering of the naphthalene rings in the side chains, and subsequent charge trapping by 1,8-naphthalimide moieties. More interestingly, by adjusting the connection sites of 1,8-naphthalimide moieties to tune the steric-twist effect, different memory properties were achieved (PMNN showed nonvolatile write once, read many (WORM) memory behavior, whereas PMNB showed volatile static RAM (SRAM) memory behavior). This result will offer a guideline for the design of different high-performance multilevel memory devices by tuning the steric effects of the chemical moieties.
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