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High-quality double-shelled TiO2 hollow spheres (DHS-Ti) assembled with TiO2 nanosheets have been synthesized for the first time through a simple hydrothermal treatment of sSiO2@TiO2 (TiO2-coated solid SiO2 spheres). The double-shelled structure shows a high BET surface area up to 417.6 m2 g−1. Anatase DHS-Ti of high crystallinity can be obtained without structural collapse by calcination treatment. The effects of cetyl trimethylammonium bromide (CTAB) concentration, pH, and hydrothermal reaction temperature have also been investigated with a series of contrast experiments. A formation mechanism involving the in situ growth of amorphous TiO2 nanosheets followed by the redeposition of dissolved silica species is proposed. Lastly, the DHS-Ti forming strategy can be extended as a general strategy to fabricate various morphological hollow nanostructures and double-shelled Pt nanocatalysts by rationally selecting functional sSiO2 nanoparticles as core materials. This work could open up a new strategy for controllable synthesis of complex hollow structures and other functional materials.

A novel type of calcium phosphate and iron(III) scale inhibitor acrylic acid-allylpolyethoxy carboxylate AA-APELn (ALn) was synthesized. The observation shows that the adsorption of the ALn copolymer on the crystal surface caused deformation of calcium phosphate crystal morphology. Furthermore, both calcium phosphate and iron(III) inhibition increase with increasing the degree of polymerization of ALn from 5 to 15, and the dosage of ALn plays an important role on calcium phosphate and iron(III) inhibition. Inhibition mechanism is proposed that the interactions between calcium or iron ions and polyethylene glycol (PEG) are the fundamental impetus to restrain the formation of the scale in cooling water systems.

BACKGROUND ZSM-5 zeolite has been used as a common support for PtSn-based catalyst in the propane dehydrogenation reaction. But owing to its high acidy, coke accommodation and stability of the catalyst are not satisfactory. Here, in order to improve the performance, the new hierarchical-porous ZSM-5 (abbreviated henceforth as ZQ) has been synthesized. RESULTS By the introduction of hierarchical-pores in ZQ, the pore structure was changed, the acid content was decreased, and the surface properties were promoted. These modifications to zeolite greatly improved the capacity of catalysts to accommodate coke. Moreover, the coke deposit on PtSnNa/ZQ migrated from active metal to the support. As expected, by using the catalyst PtSnNa/ZQ, the catalytic performance of propane dehydrogenation to propene and the stability of the catalyst were significantly promoted. CONCLUSIONS The new hierarchical-porous ZSM-5 support (ZQ) exhibits enhanced capacity to accommodate coke, and PtSnNa/ZQ enabled better propane conversion and improved catalyst stability. © 2015 Society of Chemical Industry

Novel optically active and racemic poly(N-propargylamides) bearing tyrosine pendants (LPT, DPT, and RPT) were synthesized and characterized. The polymers possessed moderate molecular weights and were thoroughly soluble in common organic solvents. The secondary structure of these three polymers in chloroform was studied and the results indicated that LPT and DPT could adopt helical structures with predominantly one-handed screw sense according to their intense Cotton effect and large specific rotation values, while RPT adopted random coiled polymer chain. The amide groups could form amide-amide hydrogen bonds to engender the twist of dihedral angle and the strong steric repulsion of phenol groups might have the opposite effect on the helix. The helical structure of the optically active polymers were conclusively constructed and stabilized by the optimization of intra- and intermolecular hydrogen bonding and steric repulsion of the side chains. Moreover, the infrared emissivity values of LPT and DPT at 30 °C were 0.682 and 0.671, which were much lower than RPT. LPT and DPT also showed superior heat resistance due to their unique helical conformation. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 133, 44824.

BACKGROUND Due to cellulose of paper is abundant, inexpensive and renewable in nature, the development of paper-based materials from cellulose to substitute materials prepared by complicated chemical routes is a fascinating challenge. This work investigates a novel method for fabricating paper-based Ni-Al layered double hydroxides (LDHs)/Al2O3 composite using celluloses as template; the fabricated composite was applied to adsorb bovine serum albumin (BSA) from water. RESULTS Scanning electron microscopy (SEM) images demonstrate the hierarchical morphologies and multiscale structures of composites at scales ranging from micro- to nano-scales. The unique macroporous structures can be directly observed by morphology analysis, and show that these materials which have potential applications in bulky biomolecules adsorption. Compared with bare LDH particles, LDHs/Al2O3 composites show a high binding capacity for BSA, where the appropriate adsorption capacity is achieved at neutral pH. The equilibrium data for BSA adsorption onto composites are found to be well described by the Langmuir isotherm model, while the kinetic data are well-fitted to the pseudo-second-order model. CONCLUSION Since the BSA adsorbed composites show near complete (over 95%) desorption in a high negative charge density of salt solution, suggesting that the paper-based Ni-Al LDHs/Al2O3 composites are practically usable for BSA separation. © 2013 Society of Chemical Industry

Allyloxy polyethoxy ether (APEG) and succinic anhydride were used to prepare allyloxy polyethoxy carboxylate (APEL). 8-hydroxy-1,3,6-pyrene trisulfonic acid trisodium salt (PY) was reacted with allyl chloride to produce fluorescent monomer 8-allyloxy-1,3,6-pyrene trisulfonic acid trisodium salt (PA). APEL and PA were copolymerized with maleic anhydride (MA) to synthesize PA tagged no phosphate and nitrogen-free calcium phosphate inhibitor POLY(MA–APEL–PA). Structures of PA, APEG, APEL, and POLY(MA–APEL–PA) were carried out by FTIR and 1H-NMR. Different MA : APEL mole ratios were employed for the manufacture of POLY(MA–APEL–PA) to study the effect of mole ratio on performance of POLY(MA–APEL–PA). Relationship between POLY(MA–APEL–PA)'s fluorescent intensity and its dosage was studied. The results indicate that capability of POLY(MA–APEL–PA) is heavily depended on the mole ratio of MA : APEL. Correlation coefficient r of POLY(MA–APEL–PA)'s fluorescent intensity and its dosage is 0.9999, and detection limit of POLY(MA–APEL–PA) is 0.86 mg/L. POLY(MA–APEL–PA) can be used to accurately measure polymer consumption on line besides providing excellent calcium phosphate inhibition. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers

A series of novel ternary-copolymer of fluorinated polyimides (PIs) were prepared from 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene (pBATB), commercially available aromatic dianhydrides, and aromatic diamines via a conventional two-step thermal or chemical imidization method. The structures of all the obtained PIs were characterized with FTIR, 1H-NMR, and element analysis. Besides, the solubility, thermal stability, mechanical properties, and moisture uptakes of the PIs were investigated. The weight-average molecular weight (Mw) and the number-average molecular weight (Mn) of the PIs were determined using gel-permeation chromatography (GPC). The PIs were readily dissolved not only in polar solvents such as DMF, DMAc, and NMP, but also in some common organic solvents, such as acetic ester, chloroform, and acetone. The glass transition temperatures of these PIs ranged from 201 to 234°C and the 10% weight loss temperatures ranged from 507 to 541°C in nitrogen. Meanwhile, all the PIs left around 50% residual even at 800°C in nitrogen. The GPC results indicated that the PIs possessed moderate-to-high number-average molecular weight (Mn), ranging from 9609 to 17,628. Moreover, the polymer films exhibited good mechanical properties, with elongations at break of 8–21%, tensile strength of 66.5–89.8 MPa, and Young's modulus of 1.04–1.27 GPa, and low moisture uptakes of 0.54–1.13%. These excellent combination properties ensure that the polymer could be considered as potential candidates for photoelectric and microelectronic applications. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Synthetic strategy for yolk–shell Fe2O3‐Pt@DSL. Novel yolk–shell Fe2O3/La2O3 ellipsoids encapsulating Pt NPs were synthesized using a facile method. A dominating mechanism for the nanocomposites involved re‐deposition and self‐assembly. The Fe2O3‐Pt@DSL catalyst showed high catalytic performance compared with other catalysts.

Novel optically active polyurethanes (BPUs) based on chiral 1,1′-binaphthol were synthesized via direct hydrogen transfer addition polymerization. The polymers were analyzed by FTIR, 1H NMR, DSC-TGA, CD spectra.The results showed that the specific rotation [α]25D were −78.0° and +54.6° for the S-BPU and R-BPU respectively, and these polymers showed better thermal stability. The circular dichroism spectra of the chiral polymers were almost identical except that they gave opposite signals at each wavelength, and the infrared emissivity values of the S-BPU and R-BPU were 0.618 and 0.682, they displayed low infrared emissivity. Meantime the polymers implanted with PEG group exhibit better solubility, however thermal stability reduced to some extent. Some properties of the new optically active polyurethanes were reported. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

Allyloxy polyethoxy ether (APEO) and chloracetic acid were used to prepare allyloxy polyethoxy carboxylate (APEC). 8-hydroxy-1,3,6-pyrenetrisulfonic acid trisodium salt was reacted with allyl chloride to produce fluorescent monomer 8-allyloxy-1,3,6-pyrene trisulfonic acid trisodium salt (AP). APEC and AP were copolymerized with maleic anhydride (MA) to synthesize AP tagged no phosphate and nitrogen free calcium phosphate inhibitor MA-APEC-AP. Structures of AP, APEO, APEC, and MA-APEC-AP were carried out by FTIR and 1H-NMR. Different MA : APEC mole ratios were employed for the manufacture of MA-APEC-AP to study the effect of mole ratio on performance of MA-APEC-AP. Relationship between MA-APEC-AP's fluorescent intensity and its dosage was studied. MA-APEC-AP's calcium phosphate inhibition was compared with the down to date calcium phosphate inhibitor (MA)-ammonium allylpolyethoxy sulphate (APES). The results indicate that capability of MA-APEC-AP is heavily depended on the mole ratio of MA : APEC. Correlation coefficient r of MA-APEC-AP's fluorescent intensity and its dosage is 0.9983, and detection limit of MA-APEC-AP is 2.03 mg L−1. MA-APEC-AP can be used to accurately measure polymer consumption on line besides providing excellent calcium phosphate inhibition. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Helical R/S-poly(urethane urea)s (R/S-HPUUs) were synthesized successfully with R/S-1,1′-binaphthyl-2′,2-diol, toluene 2,4-diisocyanate, and 1,4-diaminobenzene by a simple hydrogen-transfer addition reaction. The structure and optical properties of R/S-HPUUs were investigated systematically with Fourier transform infrared spectroscopy, 1H-NMR spectra, absorption and circular dichroism, thermogravimetry, differential scanning calorimetry, and X-ray diffraction measurements. Fourier transform infrared spectra showed that all the NH and carbonyl groups in R/S-HPUUs were hydrogen-bonded. R-HPUU and S-HPUU were two enantiomorphs with wonderful mirror-image symmetry according to circular dichroism spectroscopy analysis. R/S-HPUUs exhibited optical activity, and the optical rotations were +54.7 and −60.7°, respectively. R/S-HPUUs showed excellent thermal stability because of the plane-bifurcated interchain hydrogen bonds and helical stereostructures according to thermogravimetry, differential scanning calorimetry, and X-ray diffraction analysis. Moreover, the left-handed rotation was more stimulative for the construction of hydrogen bonds than the right-handed rotation, so S-HPUU showed higher thermal stability and better crystallizability. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Chae et al. believe that the improved CBMC measures class cohesion from the viewpoint of the usage criteria of instance variables and that it cannot allow meaningful interpretations about classes. This paper exemplifies that it characterizes the interaction patterns better than the original one does and that it could also be used as a guideline for quality evaluation so as to enable the restructuring of poorly designed classes.

Some thermally stable second-order nonlinear optical (NLO) polyimides were synthesized. The polyimides were prepared by the ring-opening polyaddition of 4,4'-(hexafluoroisopropylidene) diphthalic anhydride and pyromellitic dianhydride with two aromatic azodiamine derivatives as the NLO chromophores. These chromophores, based on a nitro group connected with azobenzene as the acceptor end of a donor-π-bridge-acceptor chromophore and a diamine group as the donor end, had specific chemical stability. On the basis of ZERNER'S INDO methods, according to the sum-over-states formula, a program for the calculation of nonlinear second-order optical susceptibilities was devised. The resulting polyimides had high number-average and weight-average molecular weights of up to 26,000 and 53,500, respectively, and a large glass-transition temperature of 248 °C. With an in situ poling and temperature ramping technique, the optimal temperatures (T opt 's) for corona poling were obtained for the largest second-order NLO response. The electrooptic coefficient (γ 33 ) of a polyimide at a wavelength of 830 nm was up to 21 pm/V after corona poling under its T opt , and the value remained at elevated temperatures (>90.6% was retained at 240 °C for >120 h). The thermal stability of the NLO polyimides was studied with UV spectrometry after poling of the films.

In this paper, a novel TiO2 nanosheets assembled double-wall hollow sphere (DHS)has been prepared successfully via hydrothermal treatment of SiO2@TiO2 with the assistant of CTAB.The prepared samples are characterized with transmission electron microscopy (TEM), scanning electron microscopy (SEM), electron spin resonance (ESR), X-ray diffraction (XRD) and X-ray photoelectron spectra (XPS), etc.Results show that redeposited silica species play a key role in the formation of the double-wall structure. The as-synthesized DHS nanostructure exhibits a large surface area (417.6 m2 g-1) and excellent mechanical strength. Furthermore, after decoration of Ag and calcination treatment, the double-shelled TiO2/Ag heterostructures show an enhanced photocatalytic performance in the degradation of RhB under UV or visible light irradiations for the following reasons: the surface plasmon resonance effect of Ag, strong interaction between Ag and TiO2 nanosheets, large surface area, excellent adsorption capacityand unique double-wall structure. On the basis of the experimental results, a possible mechanism for pollutantdegradation under visual light irradiation has been proposed.

This paper investigates the effect of aluminum hydroxide (ATH) content on the free volume and surface recovery property of polydimethylsiloxane (PDMS)–based silicone rubber containing low-molecular-weight siloxanes. With increasing ratio of ATH up to 43.1 wt %, the concentration of cyclic siloxanes (Dn = [(CH3)2SiO]n, n = 4–12) in the PDMS matrix increases remarkably, indicative of a spacing effect of ATH particles on the crosslinking of PDMS chains. When more ATH is added, the concentration of D4–D12 began to decrease. PDMS network variation is verified by free volume size corresponding to τ3 in positron annihilation lifetime spectroscopy. The o-Ps intensity decreases linearly with ATH content. Data obtained from X-ray photoelectron spectroscopy suggest the surface recovery property is weakened by ATH. This process is dominated by the amount of free volume holes in the sample. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45803.

Novel ZnO/N-doped helical carbon nanotubes (ZnO/N-HCNTs) composites were successfully synthesized via a facile chemical precipitation approach at room temperature. The sample was well characterized by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM) and ultraviolet–visible diffuse reflectance spectroscopy (UV–vis DRS). The photocatalytic activity was evaluated in the degradation of methylene blue (MB) aqueous solution under UV light irradiation. It is found that ZnO nanoparticles were highly and uniformly anchored on the surface and inner tubes of the N-HCNTs with size of about 5 nm, and significantly enhanced the photocatalytic activity compared to pure ZnO. The enhanced photocatalytic activity of ZnO/N-HCNTs composites can be ascribed to the integrative synergistic effect of effective interfacial hybridization between N-HCNTs and ZnO nanoparticles and the prolonged lifetime of photogenerated electron–hole pairs. Moreover, the ZnO/N-HCNTs could be easily recycled without any obvious decrease in photocatalytic activity and could be promote their application in the area of environmental remediation.

The polymeric scale inhibition and dispersion agents (PAYS) were prepared by graft copolymerization of acrylic acid, allylpolyethoxy carboxylate (APEY) and 2-acrylamido-2-methyl-propanesulfonic acid by using ammonium persulfate as a radical initiator in aqueous solution, among which APEY was synthesized in laboratory. Structure of PAYS was characterized by Fourier transform infrared spectroscopy. Experimental data showed that the terpolymer was a high-efficient chelate sorbent, and it exhibited excellent ability for calcium orthophosphate, with approximately 96% efficiency at the dosage of 4 mg/L, as well as high efficiency toward barium sulfate scales nearly 80% inhibition. The effectiveness of PAYS depends on the agent concentration, temperature and the ratio of the reactant. The formation of Ca3(PO4)2 and BaSO4 precipitates was characterized by scanning electron microscopy. It appeared that the crystal shape, size, and the morphology of scale changed apparently at the dosage of 4 and 15 mg/L, respectively. In addition, it has good effect on controlling iron (III) scaling. This study was also devoted to the understanding of the action mechanism of these inhibitors in suppressing the crystal nucleus formation and preventing the crystal growth. Based on the contrast experiment of scale formation, the supposing mechanism diagram was also delineated and analyzed in detail. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41546.

A novel low-phosphorus terpolymer, used as scale, corrosion inhibitor, and dispersant for iron oxide, was prepared through free-radical polymerization reaction of acrylic acid (AA), oxalic acid-allypolyethoxy carboxylate (APEM), and phosphorous acid (H3PO3) in water with redox system of hypophosphorous and ammonium persulfate as initiator. Structure of the synthesized AA-APEM-H3PO3 terpolymer was characterized by Fourier transform infrared spectrometer and 1H-NMR. The polymer possesses excellent scale inhibition performance for CaCO3, outstanding ability to disperse ferric oxide, and good corrosion inhibition properties. The study showed that AA-APEM-H3PO3 exhibited excellent ability to control calcium carbonate scale, with approximately 90.16% CaCO3 inhibition at a level of 8 mg/L AA-APEM-H3PO3. The data of the light transmittance showed that, compared to hydrolyzed polymaleic acid and polyepoxysuccinic acid, AA-APEM-H3PO3 had superior ability to control iron ions scaling. The light transmittance of the solution was about 24.1% in the presence of the terpolymer when the dosage was 8 mg/L. Moreover, the corrosion inhibition efficiency could reach up to 79.77% at a dosage of 30 mg/L, with ethylene diamine tetra methylene phosphonic acid just 39.62%. Scanning electronic microscopy, transmission electron microscope, and X-ray powder diffraction analysis were used to investigate the effect of AA-APEM-H3PO3 on morphology of calcium carbonate scale. The low-phosphorous terpolymer has also been proven to be effective inhibitor of calcium carbonate even at increasing solution temperature, pH, and Ca2+ concentration. The proposed inhibition mechanism suggests the surface complexation and chelation between the functional groups P(O) (OH)2, COOH and Ca2+, with polyethylene glycol segments increasing its solubility in water. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41447.