Carbon dioxide (CO2) is an abundant C1 feedstock with tremendous potential to produce versatile building blocks in synthetic applications. Given the adverse impact of CO2 on the atmosphere, it is of paramount importance to devise strategies for upcycling it into useful materials, such as polymers and fine chemicals. To activate such stable molecule, superbases offer viable modes of binding to CO2. In this study, a superbase cyclopropenimine derivative was found to exhibit exceptional proficiency in activating CO2 and mediating its polymerization at ambient temperature and pressure for the synthesis of polyurethanes. The versatility of this reaction can be extended to monofunctional amines and alcohols, yielding a variety of functional carbonates and carbamates.

Synthesis of a polymer composed of a large discrete number of chemically distinct monomers in an absolutely defined aperiodic sequence remains a challenge in polymer chemistry. The synthesis has largely been limited to oligomers having a limited number of repeating units due to the difficulties associated with the step-by-step addition of individual monomers to achieve high molecular weights. Here we report the copolymers of α-hydroxy acids, poly(phenyllactic- co -lactic acid) (PcL) built via the cross-convergent method from four dyads of monomers as constituent units. Our proposed method allows scalable synthesis of sequence-defined PcL in a minimal number of coupling steps from reagents in stoichiometric amounts. Digital information can be stored in an aperiodic sequence of PcL, which can be fully retrieved as binary code by mass spectrometry sequencing. The information storage density (bit/Da) of PcL is 50% higher than DNA, and the storage capacity of PcL can also be increased by adjusting the molecular weight (~38 kDa).

Photo-crosslinked polymer cubosomes can work as robust nanoreactor under organic solvent condition without structural degradation.

The morphological control of nanostructures created by the self-assembly of macromolecular building blocks in solution has practical importance because the structural parameters of nanostructures greatly affect their physical and chemical behavior in solution, for example, pharmacokinetics. Herein, we report that the stimuli-induced changes to the conformation of the hydrophilic polymer block of a block copolymer (BCP), in this case branched-linear poly(ethylene glycol)-b-poly(styrene) BCPs, are translated to changes in the morphology of the BCP self-assemblies in solution. Specifically, the cone angle between the poly(ethylene glycol) arms in the tri-arm hydrophilic block equipped with pyridyl units in the scaffold can be changed by varying the self-assembly conditions, thus affecting the packing parameter (p) of the BCP. Upon increasing the cone angle by protonating the pyridyl units, the self-assembled BCP structures underwent changes consistent with a reduction in the p value. In contrast, the chelation of zinc metal cations (Zn2+) to the pyridyl groups resulted in the conformation of the hydrophilic block taking on a closed form, resulting in an apparent increase in the p value of the BCP. Our results could be applied to stimuli-dependent morphological transitions of other self-assembled BCP nanostructures in solution.

A π-conjugated dialkoxynaphthalene-based donor-acceptor copolymer was synthesized by a Suzuki coupling reaction, and its photophysical, thermal and electrochemical properties and photovoltaic characteristics were characterized. The copolymer showed good solubility and a weight average molecular weight of 11,500. The new copolymer was characterized by two absorption bands at 315 and 403 nm in the dilute solution, which were assigned to the π→π* transition and an intramolecular charge transfer band, respectively. The wide band gap of the donor-acceptor copolymer was explained by the 3-dimensional structure and tortional angle between the dialkoxynaphthalene and benzothiadiazole of the model compound. The PCE of the photovoltaic solar cell device fabricated using this copolymer reached 0.06% with a V oc , J sc , and FF of 0.59, 0.3, and 33%, respectively.

A new semiconducting polymer, poly((5,5-E-alpha-((2-thienyl)methylene)-2-thiopheneacetonitrile)-alt-2,6-[(1,5-didecyloxy)naphthalene])) (PBTADN), an alternating copolymer of 2,3-bis-(thiophene-2-yl)-acrylronitrile and didecyloxy naphthalene, is synthesized and used as an active material for organic thin film transistors (OTFTs) and organic solar cells. The incorporation of 2,3-bis-(thiophene-2-yl)-acrylronitrile as an electron deficient group and didecyloxy naphthalene as an electron rich group resulted in a relatively low bandgap, high charge carrier mobility, and finally good photovoltaic performances of PBTADN solar cells. Because of the excellent miscibility of PBTADN and PC71BM, as confirmed by Grazing Incident X-ray Scattering (GIXS) measurements and Transmission Electron Microscopy (TEM), homogeneous film morphology was achieved. The maximum power conversion efficiency of the PBTADN:PC71BM solar cell reached 2.9% with a V-oc of 0.88 V, a short circuit current density (J(sc)) of 5.6 mA/cm(2), and a fill factor of 59.1%. The solution processed thin film transistor with PBTADN revealed a highest saturation mobility of 0.025 cm(2)/Vs with an on/off ratio of 10(4). The molecular weight dependence of the morphology, charge carrier mobility, and finally the photovoltaic performances were also studied and it was found that high molecular weight PBTADN has better self assembly characteristics, showing enhanced performance. (C) 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 49: 1119-1128, 2011

We describe the design of an nRERL microprocessor for ultra-low-energy applications, nRERL (nMOS Reversible Energy Recovery Logic) is a new reversible adiabatic logic circuit using only nMOS transistors, which can be operated at the leakage-current level. We focus on two main issues; first, the design of a full adiabatic microprocessor, which uses only adiabatic components for all the functional blocks, second, the energy consumption of the nRERL microprocessor including its clocked power generator (CPG). With the experimental results, the nRERL microprocessor consumed 26.22 pJ at 440 kHz.

In this paper, we propose an adiabatic register file for ultra-low-energy applications, which uses a new reversible adiabatic logic, nRERL. The nRERL register file discards garbage information with minimal energy dissipation. We designed a 16/spl times/8b three-port nRERL register file. From SPICE simulations, we found that the nRERL register file consumes less than 10% of the energy consumed in the conventional register file at a frequency of lower than 1 MHz. We also describe how to design a RAM, a large array of storage cells.