Successive stepwise evolution of host layer‐stacking framework upon the intercalation of mobile vapor guests within side‐chain layers

For the ordered phases of hairy‐rod semiconductive poly(2,5‐bis(3‐tetradecylthiophene‐2‐yl)thieno[3,2‐b]thiophene) (PBTTT) sandwiched in between crystalline platelets of hexamethylbenzene, the successive stepwise evolution of layer‐stacking framework upon guest intercalation has been studied in this research. The direct consequence of the guest intercalation into side‐chain layers is evaluated to cause the lateral shift of thiophene backbones along π–π stacking, resulting in stepwise shift of ultraviolet absorption wavelength. The thermal motions of vapor guests within disordering side‐chain layers subsequently cause progressive expansion of host stacking framework. With the increase in side‐chain length, thicker layers of disordering side chains in liquid crystals (LCs) accommodate additional vapor guests and larger amplitudes of thermal motions of guests, hence promoting the level of reversible d‐spacing change. The mixing between mobile vapor guests and aliphatic side chains is clarified as the mechanism of guest intercalation, which rationalizes successive guest intercalation during heating and the contribution of disordering side‐chain layers. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017 , 55, 1448–1456     

Structural and electronic properties of type-I and type-VIII Ba8Ga16Sn30 clathrates under compression

The total energy and electronic structures for type-I (β phase) and type-VIII (α phase) Ba₈Ga₁₆Sn₃₀ clathrates under hydrostatic pressure have been investigated using density functional theory (DFT) calculations. It was found that the type-VIII phase is more stable than the type-I one at ambient conditions and that β→α phase transition can not occur under hydrostatic pressure. The band structures show that the type-I and type-VIII Ba₈Ga₁₆Sn₃₀ are indirect semiconductors with band gaps of 0.24 eV and 0.19 eV, respectively. The results suggested that type-I clathrate Ba₈Ga₁₆Sn₃₀ has a larger value of the thermoelectric (TE) power than that of type-VIII clathrate. We found that pressure tuning changes the k-point of conduction band minimum (CBM) in the Brillouin zone for β-phase, but it is not the case for α-phase. Furthermore, the results show that the pressure can change the interaction between guest atoms and the host lattice, and consequently results in the decrease of the band gap of β-phase and the increase of the band gap of α-phase, indicating that the pressure effect can play an important role in the magnitude of the TE power.     

Preparation and solution properties of a novel cationic hydrophobically modified polyacrylamide for enhanced oil recovery

Abstract

A novel cationic water-soluble monomer allyldimethylisooctylammonium bromide (ADIAB) containing a short-chain alkane was synthesized successfully. This monomer was copolymerized with acrylamide and sodium acrylate to produce hydrophobically modified polyacrylamide (HMPAM) using solution polymerization without surfactants. The structures of monomer ADIAB and HMPAM were characterized with infrared spectroscopy and nuclear magnetic resonance spectroscopy. Influence of preparation condition on viscosities of products was studied. The aqueous solution viscosity of the terpolymer was also investigated as functions of concentration, temperature and salinity. The results showed that when the temperature exceeds the 60?°C and NaCl concentration exceeds about 2000?mg/L, the temperature and salt tolerance characters of terpolymer were demonstrated. The enhanced oil recovery tests were initially carried out using homogeneous sandpack models.     

Microwave solid phase synthesis, characterization, and antimicrobial activity of 3,5-diiodo-salicylalidene-glycine-cobalt(II)

One mononuclear complex, C₉H₇I₂NO₄Co(II) (I) with 3,5-diiodo-salicylalidene, glycine and Co(CH₃COO)₂ · 4H₂O were microwave solid synthesized. The complex was characterized by X-ray crystallography, UV, IR, ESI-MS, and elemental analyses. In addition, further investigation revealed that the central cobalt(II) atom in complex is five-coordinated by one nitrogen atom and four oxygen atoms. The complex was assayed for antibacterial (B. subtilis, S. aureus, S. faecalis, P. aeruginosa, E. coli, and E. cloacae) activities by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl trtrazolium bromide) method. Complex I showed favorable antimicrobial activity with MICs of 3.125, 6.25, 6.25, 6.25, 3.125, and 6.25 μg/mL against B. subtilis, S. aureus, S. faecalis, P. aeruginosa, E. coli, and E. cloacae, respectively.     

Synthesis of 2-(1-Arylcarbonyl-1-arylazomethylidene)-thiazolidines by the Reaction of 2-(Arylcarbonyl-methylidene)thiazolidines with Diazobenzenes

A variety of 2-(1-arylcarbonyl-1-arylazomethylidene)-thiazolidenes were synthesized in excellent yields by the reaction of 2-(arylcarbonylmethylidene)thiazolidines with diazobenzenes.     

Improved staining of phosphoproteins with high sensitivity in polyacrylamide gels using Stains‐All

An improved Stains‐All (ISA) staining method for phosphoproteins in SDS‐PAGE was described. Down to 0.5–1 ng phosphoproteins (α‐casein, β‐casein, or phosvitin) can be successfully selectively detected by ISA stain, which is approximately 120‐fold higher than that of original Stains‐All stain, but is similar to that of commonly used Pro‐Q Diamond stain. Furthermore, unlike the original Stains‐All protocol that was time consuming and light unstable, ISA stain could be completed within 60 min without resorting to protect the gels from light during the whole staining procedure. According to the results, it is concluded that ISA stain is a rapid, sensitive, specific, and economic staining method for a broad application to the research of phosphoproteins.     

Indecomposable representations and boson realizations of the nonlinear deformed angular momentum algebra of Witten’s first type

In this paper indecomposable representations and boson realizations of the nonlinear angular momentum algebra $\mathcal{R}_{q,p}^{c_1,c_2,c_3}$ of Witten’s first type are investigated in a purely algebraic manner. Explicit form of the master representation of $\mathcal{R}_{q,p}^{c_1,c_2,c_3}$ on the space of its universal enveloping algebra is given. Then, from this master representation, other indecomposable representations are obtained in explicit form. Various kinds of single-boson, single inverse boson, and double-boson realizations of $\mathcal{R}_{q,p}^{c_1,c_2,c_3}$ are respectively obtained by generalizing the Holstein–Primakoff realization, the Dyson realization, and the Jordan–Schwinger realization of the Lie algebras SU(2) and SU(1,1). For each kind, the unitary realization, the nonunitary realization, and their connection by the corresponding similarity transformation are respectively discussed. Using a kind of double-boson realizations, the irreducible representation of $\mathcal{R}_{q,p}^{c_1,c_2,c_3}$ in the angular momentum basis is given.     

A novel efficient protocol for preparation of 3-formyl-2-arylbenzo[b]furan derivatives

An efficient method for preparation of 3-formyl-2-arylbenzo[b]furan derivatives 4 from 3-chloro-2-(2-methoxyaryl)-1-arylprop-2-en-1-one 2 was developed, and the desired product was obtained in good to excellent yields. By converting 2-(2-methoxyphenyl)-3-oxo-3-phenylpropanal 1 to 2, the regioselectivity problem occurring in the reaction when using 1 as the starting material was successfully avoided. Furthermore, a one-pot procedure for the successive demethylation, cyclization, and hydrolysis was evolved, although the intermediate 3-(dibromomethyl)-2-phenylbenzo[b]furan 3a could be isolated. A plausible mechanism was proposed based on some in situ investigations.     

Pt/NbPWO双功能催化剂的制备及氢解碱木质素制备芳香单体

木质素是一种天然芳香族聚合物,约占木质纤维素的30%,是唯一通过裂解C―O醚键和C―C键生产芳香族化学品或液体燃料的可再生芳香族资源。迄今为止,对木质素氢解制备有价值化合物的研究主要集中在相对不稳定的C―O键的裂解上,这限制了木质素氢解的效率。采用水热法和湿浸渍法制备了多功能Pt/NbPWO催化剂。通过破坏碱木质素中的C―O键和C―C键,可以得到产率为18.02%的芳香族单体。该反应不仅可以断裂木质素聚合物中醚键,同时也可以断裂部分关键的C―C键。其氢解机理可能是丰富的Brønsted酸和Lewis酸位点参与了C―C的活化。此外,重点分析载体和Pt物种在Pt/NbPWO催化剂中的协同作用。     

Removal of Cu(II) Contamination from Aqueous Solution by Ethylenediamine@β-Zeolite Composite

The low cost β-zeolite and ethylenediamine modified β-zeolite (EDA@β-zeolite) were prepared by self-assembly method and used for Cu(II) removal from contaminated aqueous solution. Removal ability of β-zeolite toward Cu(II) was greatly improved after ethylenediamine (EDA) modification, the removal performance was greatly affected by environmental conditions. XPS results illustrated that the amide group played important role in the removal process by forming complexes with Cu(II). The EDA@β-zeolite showed desirable recycling ability. The finding herein suggested that the proposed composite is a promising and suitable candidate for the removal of Cu(II) from contaminated natural wastewater and aquifer.