• Macromolecular Research
• /
• v.17 no.9
• /
• pp.631-637
• /
• 2009

This study examined the unique self-doping behavior of carboxylated polyaniline (PCA). The self-doped PCA was synthesized using an environmentally benign enzymatic polymerization method with cationic surfactants. XPS showed that HCl-doped PCA contained approximately 34% of protonated amines but self-doped PCA contained 9.6% of the doped form of nitrogen at pH 4. FTIR and elemental analysis showed that although the PCA was doped with the proton of strong acids at low pH via the protonation of amines, the self-doping mechanism of PCA at pH > 4 was mainly due to hydrogen bonding between the carboxylic acid group and amine group.

• Bulletin of the Korean Chemical Society
• /
• v.32 no.11
• /
• pp.4011-4015
• /
• 2011

We explored the interpretation of the well-accepted correlation between the apparent peak maximum position shift and extent of molecular interactions, like hydrogen bonding and dipole-dipole interactions, based on the overlapped multiple band model. The simulation of two overlapped Lorentzian bands was carried out to interpret how the maximum position of a composite peak relates to the relative contributions of two species representing the different levels of molecular interactions, i.e., free (or very weekly bound) vs. strongly bound. To demonstrate the validity of our interpretation of the origin of the peak position shift, the temperaturedependent IR spectra of ethylene glycol were also analyzed. It was found through the analysis of simulated and experimental spectra that the apparent peak shift in certain case can be safely interpreted as the measure of the strength of hydrogen bonding. The result of this study gives a new insight to interpret molecular interactions probed by vibrational spectroscopy.

• Bulletin of the Korean Chemical Society
• /
• v.34 no.6
• /
• pp.1814-1822
• /
• 2013

By using density functional theory calculations, we have performed a systemic study on the electronic structures and topological properties of interactions between N-butylpyridinium nitrate ($[BPY]^+[NO_3]^-$) and thiophene (TS), benzothiophene (BT), dibenzothiophene (DBT), naphthalene (NAP). The most stable structure of $[BPY]^+[NO_3]^-$ ion pair indicates that hydrogen bonding interactions between oxygen atoms on $[NO_3]^-$ anion and C2-H2 on pyridinium ring play a dominating role in the formation of ion pair. The occurrence of hydrogen bonding, ${\pi}{\cdots}$H-C, and ${\pi}{\cdots}{\pi}$ interactions between $[BPY]^+[NO_3]^-$ and TS, BT, DBT, NAP has been corroborated at the molecular level. But hydrogen bonding and ${\pi}{\cdots}{\pi}$ interactions between $[BPY]^+[NO_3]^-$ and NAP are weak in terms of structural properties and NBO, AIM analyses. DBT is prior to adsorption on N-butylpyridinium nitrate ionic liquid.

• Fibers and Polymers
• /
• v.3 no.3
• /
• pp.97-102
• /
• 2002

A series of waterbome poly(urethane-urea) anionomers were prepared from isophorone diisocyanate (IPDI), polycaprolactone diol (PCL), dimethylol propionic acid (DMPA), ethylene diamine (EDA), and triethylamine (TEA), NaOH, or Cu($(COOCH_3)_2$) as neutralizing agent. This study was performed to decide the effect of neutralizing agent type on the particle size viscosity, hydrogen bonding index, adhesive strength, antistaticity, antibacterial and mechanical properties. The particle size of the dispersions decreased in the following order: TEA based samples (T-sample), NaOH based samples (N-sample), and Cu($(COOCH_3)_2$) based sample (C-sample). The viscosity of the dispersions increased in the order of C-sample, N-sample, and T-sample. Metal salt based film samples Of and C-sample) had much higher antistaticity than TEA based sample. By infrared spectroscopy, it was found that the hydrogen bonding index (or fraction) of samples decreased in the order of T-sam-pie, N-sample, and C-sample. The adhesive strength and tensile modulus/strength decreased in the order of T-sample, N-sam-pie, and C-sample. The C-sample had strong antibacterial halo, however, T- and N-samples did not

• Macromolecular Research
• /
• v.16 no.5
• /
• pp.446-456
• /
• 2008

A recent theoretical approach based on the coupling of both the Flory-Huggins (FH) and the Association Equilibria thermodynamic (AET) theories was modified and adapted to study the miscibility properties of a multi-component system formed by two polymers (a proton-donor and a proton-acceptor) and a proton-acceptor solvent, named copolymer(A)/solvent(B)/polymer(C). Compatibility between polymers was mainly attained by hydrogen-bonding between the hydroxyl group on the phenol unit of the poly(styrene-co-vinyl phenol) (PSVPh) and the carbonyl group of the biodegradable and environmentally friendly poly(3-hydroxybutyrate) (PHB). However, the self-association of PSVPh and specific interactions between the PSVPh and the H-acceptor group (an ether oxygen atom) of the epichlorohydrin (ECH) solvent were also established in a lower extension, which competed with the polymer-polymer association. All the binary specific interactions and their dependence with the system composition as well as with the copolymer content were evaluated and quantified by means of two excess functions of the Gibbs tree energy, ${\Delta}g_{AB}$ and ${\Delta}g_{AC}$. Experimental results from fluorescence spectroscopy were consistent with the theoretical simulations derived with the model, which could also be applied and extended to predict the miscibility in solution of any polymer blend with specific interactions.

• Transactions of the Korean hydrogen and new energy society
• /
• v.27 no.3
• /
• pp.306-310
• /
• 2016

In Na-base Battery for ESS, ${\alpha}-Al_2O_3$ and metal bonding was used to prevent direct reaction between electrolyte and electrode. The hard metal was metalized at $1600^{\circ}C$ in a flowing hydrogen gas for high bonding strength. In this study, instead of hard metal metalizing, Ni was plated on ${\alpha}-Al_2O_3$ by electroless Ni plating technique and then bonded with metal. To enhance the bonding strength, surface of ${\alpha}-Al_2O_3$ was treated with $H_3PO_4$. The effects of strength and leakage of joining as a function of acid treatment time on ${\alpha}-Al_2O_3$ are described.

• Journal of the Korean Vacuum Society
• /
• v.9 no.4
• /
• pp.382-388
• /
• 2000

Hydrogenated amorphous carbon (a-C:H) films were fabricated by electron cyclotron resonance plasma-enhanced chemical vapor deposition. The bonding structure of carbon and hydrogen in the a-C:H films has been investigated by varying the deposition conditions such as ECR power, gas composition of methane and hydrogen, deposition time, and negative DC self bias voltage. The bonding characteristics of the a-C:H thin film were analyzed using FTIR spectroscopy. The IR absorption peaks of the film were observed in the range of $2800\sim3000 \textrm{cm}^{-1}$. The atomic bonding structure of a-C:H film consisted of $sp^3$ and $sp^2$ bonding, most of which is composed of $sp^3$ bonding. The structure of the a-C:H films changed from $CH_3$ bonding to $CH_2$ or CH bonding as deposition time increased. We also found that the amount of dehydrogenation in a-C:H films was increased as the bias voltage increased.

• Proceedings of the KIEE Conference
• /
• 1999.07g
• /
• pp.3279-3281
• /
• 1999

This paper describes a method of direct wafer bonding using surfaces activated by a radio-frequency hydrogen plasma. The hydrogen plasma cleaning of silicon in the RIE mode was investigated as a pretreatment for silicon direct bonding. The cleaned silicon surface was successfully terminated by hydrogen, The hydrogen-terminated surfaces were rendered hydrophilic, which could be wetted by Dl water rinse. Two wafers of silicon and silicon dioxide were contacted to each other at room temperature and postannealed at $300{\sim}1100^{\circ}C$ in an $N_2$ atmosphere for 2 h. From the AFM results, it was revealed that the surface became rougher with the increased plasma exposure time and power. The effect of the plasma treatment on the surface chemistry was investigated by the AES analysis. It was shown that the carbon contamination at the surface could be reduced below 5 at %. The interfacial energy measured by the crack propagation method was 122 $mJ/m^2$ and 384 $mJ/m^2$ for RCA cleaning and hydrogen plasm, respectively.

• Journal of Adhesion and Interface
• /
• v.15 no.4
• /
• pp.161-168
• /
• 2014

New self-assembled discotic liquid crystals have been prepared through single hydrogen bonding between phenol and pyridine moieties, and their liquid crystalline properties were investigated. For the construction of discotic structure, we used phloroglucinol as a core molecule and trans-4-alkoxy-4'-stilbazoles with systematically varied alkyl chain lengths as peripheral units. FTIR results showed that the intermolecular hydrogen bonds between core and peripheral molecules are successfully formed, and the stability of the hydrogen bond is strongly influenced by molecular ordering. Discotic complexes exhibited different liquid crystalline phases depending on the length of alkyl chains around the discotic mesogen. The discotic complexes with longer alkyl chains showed hexagonal columnar mesophases, while the other complexes formed nematic columnar mesophases. These results indicated that the type of mesophase structure was strongly dependent on the alkyl chain length around the aromatic core.

• Journal of Institute of Convergence Technology
• /
• v.5 no.2
• /
• pp.43-48
• /
• 2015

Deep eutectic solvents (DESs) are now broadly understood as a new kind of ionic liquid (IL) because they exhibit many characteristics and properties similar with ILs. The DESs made of quaternary ammonium salt blended with one of hydrogen bonding donor (HBD) compounds behave as ILs even at very low temperature. In this study, properties such as density, viscosity, surface tension, conductivity, and electrochemical behavior of DESs were reported and their applications were reviewed. Study on DESs has been drawn attention on application in metal finishing, but these solvents can be used in a variety of synthesis, and their potentials have been demonstrated in various areas. DESs are expected to offer applicability by extending the types of salts and hydrogen bond donor mixtures.