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Cationic polymers

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https://www.readbyqxmd.com/read/28342356/heterogeneous-oxidative-desulfurization-of-diesel-fuel-catalyzed-by-mesoporous-polyoxometallate-based-polymeric-hybrid
#1
Huawei Yang, Bin Jiang, Yongli Sun, Luhong Zhang, Zhaohe Huang, Zhaoning Sun, Na Yang
In this work, the simple preparation of novel polymer supported polyoxometallates (POMs) catalysts has been reported. Soluble task-specific cross-linked poly (ionic liquid) (PIL) was prepared with N,​N-​dimethyl-​dodecyl-​(4-​vinylbenzyl) ammonium chloride and divinylbenzene as co-monomers. The as-prepared cationic PILs were assembled with different commercial POMs to form the interlinked mesoporous catalysts, and the formation mechanism was provided. The catalytic oxidation activities of the catalysts were closely related to the formation pathway of their corresponding peroxide active species...
March 10, 2017: Journal of Hazardous Materials
https://www.readbyqxmd.com/read/28336848/effects-of-iodine-doping-on-optoelectronic-and-chemical-properties-of-polyterpenol-thin-films
#2
Kateryna Bazaka, Mohan V Jacob
Owing to their amorphous, highly cross-liked nature, most plasma polymers display dielectric properties. This study investigates iodine doping as the means to tune optoelectronic properties of plasma polymer derived from a low-cost, renewable resource, i.e., Melaleuca alternifolia oil. In situ exposure of polyterpenol to vapors of electron-accepting dopant reduced the optical band gap to 1.5 eV and increased the conductivity from 5.05 × 10(-8) S/cm to 1.20 × 10(-6) S/cm. The increased conductivity may, in part, be attributed to the formation of charge-transfer complexes between the polymer chain and halogen, which act as a cation and anion, respectively...
January 13, 2017: Nanomaterials
https://www.readbyqxmd.com/read/28335332/micromechanical-properties-of-nanostructured-clay-oxide-multilayers-synthesized-by-layer-by-layer-self-assembly
#3
Dongwei Hou, Guoping Zhang, Rohit Raj Pant, Zhongxin Wei, Shuilong Shen
Clay-based nanostructured multilayers, such as clay-polymer multilayers and clay-oxide multilayers, have attracted growing attention owing to their remarkable mechanical properties and promising application in various fields. In this paper, synthesis of a new kind of nanostructured clay-oxide multilayers by layer-by-layer self-assembly was explored. Nano-mechanical characterization of 18 clay-based multilayer samples, prepared under as-deposited (i.e., air-dried) and annealing conditions at 400 °C/600 °C with different precursor cations and multilayer structure, were carried out using nanoindentation testing, atomic force microscopy (AFM), and X-ray diffraction (XRD)...
November 8, 2016: Nanomaterials
https://www.readbyqxmd.com/read/28334651/dispersive-micro-solid-phase-extraction-of-amantadine-rimantadine-and-memantine-in-chicken-muscle-with-magnetic-cation-exchange-polymer
#4
Dawei Chen, Hong Miao, Yunfeng Zhao, Yongning Wu
This study demonstrated a novel dispersive micro solid phase extraction (DMSPE) method for extraction of adamantane drugs (amantadine, rimantadine and memantine) in chicken muscle. The adamantane drugs were extracted from chicken muscle using 1% acidic acetonitrile as extraction solvent. The cleanup of fatty matrices from analytes was achieved by the DMSPE technique using magnetic cation exchange polymer as adsorbent. In this procedure, the experimental parameters and conditions were optimized in detail for the improvement of extraction efficiency...
March 10, 2017: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/28332813/competitive-adsorption-of-polyelectrolytes-onto-and-into-pellicle-coated-hydroxyapatite-investigated-by-qcm-d-and-force-spectroscopy
#5
Hyun-Su Lee, Carl Myers, Lynette Zaidel, Prathima Chandra Nalam, Matthew Alexander Caporizzo, Carlo Daep, David M Eckmann, James G Masters, Russell J Composto
A current effort in preventive dentistry is to inhibit surface attachment of bacteria using antibacterial polymer coatings on the tooth surface. For the antibacterial coatings, the physisorption of anionic and cationic polymers directly onto hydroxyapatite (HA) and saliva treated HA surfaces was studied using quartz crystal microbalance, force spectroscopy and atomic force microscopy. First, single species adsorption is shown to be stronger on HA surfaces than on silicon oxide surfaces for all polymers (i.e...
March 23, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28329442/poly-ether-ester-ionomers-as-water-soluble-polymers-for-material-extrusion-additive-manufacturing-processes
#6
Allison M Pekkanen, Callie Zawaski, Andre Stevenson, Ross Dickerman, Abby Whittington, Christopher Bryant Williams, Timothy E Long
Water-soluble polymers as sacrificial supports for additive manufacturing (AM) facilitate complex features in printed objects. Few water-soluble polymers beyond poly(vinyl alcohol) enable material extrusion AM. In this work, charged poly(ether ester)s with tailored rheological and mechanical properties serve as novel materials for extrusion-based AM at low temperatures. Melt transesterification of poly(ethylene glycol) (PEG, 8k) and dimethyl 5-sulfoisophthalate afforded poly(ether ester)s of sufficient molecular weight to impart mechanical integrity...
March 22, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28328033/effects-of-molecular-weight-and-cationization-agent-on-the-sensitivity-of-bi-cluster-secondary-ion-mass-spectrometry
#7
Makiko Fujii, Rie Shishido, Takaya Satoh, Shigeru Suzuki, Jiro Matsuo
RATIONALE: Bi cluster secondary ion mass spectrometry (SIMS) is one of the most promising tools for precise analysis of synthetic polymers. However, the sensitivity in the high-mass region is still insufficient compared with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS). Accordingly, the effects of metal assistance (cationization agents) were investigated in this study. METHODS: To investigate the effects caused by varying the ionization agent, three different polyethylene glycol (PEG) samples were prepared, one with an Ag-deposited film, and two others mixed with Ag and Na, respectively...
July 30, 2016: Rapid Communications in Mass Spectrometry: RCM
https://www.readbyqxmd.com/read/28327749/mono-and-polynuclear-ag-i-complexes-of-n-functionalized-bis-diphenylphosphino-amine-dppa-type-ligands-synthesis-solid-state-structures-and-reactivity
#8
Alessio Ghisolfi, Christophe Fliedel, Pierre de Frémont, Pierre Braunstein
The reactivity of the N-functionalized DPPA-type ligands (Ph2P)2N(p-Z)C6H4 [Z = H (1a), SMe (1b), OMe (1c)] with AgBF4 was investigated and revealed an unexpected influence of the para substituent Z of the N-aryl ligand. In acetone, the mononuclear bis-chelated [Ag{(1a-1c)-P,P}2]BF4 (2a·BF4-2c·BF4) and dinuclear bridged [Ag2{μ2-(1a-1c)-P,P}2](BF4)2 [3a·(BF4)2-3c·(BF4)2] complexes were obtained with a 1 : 2 and 1 : 1 AgBF4/ligand molar ratio, respectively. While the molecular structures of 2a·BF4 and 2b·BF4 determined in the solid-state by X-ray diffraction revealed their mononuclear nature and the absence of cation/anion interaction, complexes 3b·(BF4)2 and 3c·(BF4)2 form 2D coordination polymers through intermolecular Ag-S or Ag-O interactions, respectively, involving the N-function of the respective DPPA-type ligand, and display direct interactions between one BF4 anion and both Ag(i) cations...
March 22, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28325042/enhanced-endosomal-escape-by-light-fueled-liquid-metal-transformer
#9
Yue Lu, Yiliang Lin, Zhaowei Chen, Quanyin Hu, Yang Liu, Shuangjiang Yu, Wei Gao, Michael D Dickey, Zhen Gu
Effective endosomal escape remains as the "holy grail" for endocytosis-based intracellular drug delivery. To date, most of the endosomal escape strategies rely on small molecules, cationic polymers, or pore-forming proteins, which are often limited by the systemic toxicity and lack of specificity. We describe here a light-fueled liquid-metal transformer for effective endosomal escape-facilitated cargo delivery via a chemical-mechanical process. The nanoscale transformer can be prepared by a simple approach of sonicating a low-toxicity liquid-metal...
March 22, 2017: Nano Letters
https://www.readbyqxmd.com/read/28324594/polymers-in-the-delivery-of-sirna-for-the-treatment-of-virus-infections
#10
REVIEW
Nicholas Reynolds, Megan Dearnley, Tracey M Hinton
Viral diseases remain a major cause of death worldwide. Despite advances in vaccine and antiviral drug technology, each year over three million people die from a range of viral infections. Predominant viruses include human immunodeficiency virus, hepatitis viruses, and gastrointestinal and respiratory viruses. Now more than ever, robust, easily mobilised and cost-effective antiviral strategies are needed to combat both known and emerging disease threats. RNA interference and small interfering (si)RNAs were initially hailed as a "magic bullet", due to their ability to inhibit the synthesis of any protein via the degradation of its complementary messenger RNA sequence...
April 2017: Topics in Current Chemistry (Journal)
https://www.readbyqxmd.com/read/28323412/temporary-single-cell-coating-for-bioprocessing-via-a-cationic-polymer
#11
Ricardo Da Conceicao Ribeiro, Deepali Pal, David Jamieson, Kenneth Samora Rankin, Matthew Benning, Kenneth W Dalgarno, Ana Marina Ferreira
Temporary single cell coating is a useful tool for cell processing, allowing manipulation of cells to prevent cell attachment and agglomeration, before re-establishing normal cell function. In this paper, a speckled coating method using a known polycation (poly-L-lysine, PLL) is described to induce cell surface electrostatic charges on three different cell types - two bone cancer cell lines and fibroblasts. The morphology of the PLL speckled coating on the cell surface, internalization and metabolization of the polymer, and prevention of cellular aggregations are reported...
March 21, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28323177/biodegradable-cationic-poly-carbonates-effect-of-varying-side-chain-hydrophobicity-on-key-aspects-of-gene-transfection
#12
Zhan Yuin Ong, Chuan Yang, Wei Cheng, Zhi Xiang Voo, Willy Chin, James L Hedrick, Yi Yan Yang
The degree of hydrophobicity in cationic polymers plays an important but often underappreciated role in the safety and efficacy of gene delivery processes. In order to further elucidate structure-activity relationships of biodegradable cationic poly(carbonate) gene carriers, we synthesized a series of narrowly dispersed homo-polymers via metal-free organocatalytic living ring-opening polymerization (ROP) of cyclic carbonate monomers bearing either alkyl (propyl, hexyl or nonyl) or 4-methyl benzyl halide side chains...
March 17, 2017: Acta Biomaterialia
https://www.readbyqxmd.com/read/28322564/bioreducible-zinc-ii-coordinative-pei-with-low-molecular-weight-for-robust-gene-delivery-of-primary-and-stem-cells
#13
Shuai Liu, Dezhong Zhou, Jixiang Yang, Hao Zhou, Jiatong Chen, Tianying Guo
To transform the common low molecular weight (LMW) cationic polymers, such as polyethylenimine (PEI) to highly efficient gene vectors will be of great significance but remains challenging. Since that LMW cationic polymers perform far less efficient to their high molecular weight counterparts mainly due to weaker nucleic acid encapsulation, herein, we report the design and synthesis of a dipicolylamine (DPA)-based disulfide-containing zinc(II) coordinative module (Zn-DDAC), which is used to functionalize LMW PEI (Mw~1800 Da) to give a non-viral vector (Zn-PD) with high efficiency and safety in primary and stem cells...
March 21, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28321944/self-assembling-brush-polymers-bearing-multisaccharides
#14
Jongchan Lee, Jin Chul Kim, Hoyeol Lee, Sungjin Song, Heesoo Kim, Moonhor Ree
Three different series of brush polymers bearing glucosyl, maltosyl, or maltotriosyl moiety at the bristle end are successfully prepared by using cationic ring-opening polymerization and two sequential postmodification reactions. All brush polymers, except for the polymer containing 100 mol% maltotriosyl moiety, demonstrate the formation of multibilayer structure in films, always providing saccharide-enriched surface. These self-assembling features are remarkable, regarding the bulkiness of saccharide moieties and the kink in the bristle due to the triazole linker...
March 21, 2017: Macromolecular Rapid Communications
https://www.readbyqxmd.com/read/28316813/crystal-structure-of-poly-aqua-%C3%AE-2-3-di-hydro-thieno-3-4-b-1-4-dioxine-5-7-di-carboxyl-ato-%C3%AE%C2%BA-2-o-5-o-7-%C3%AE-di-pyridin-4-yl-sulfane-%C3%AE%C2%BA-2-n-n-zinc-0-26-hydrate
#15
Wen-Liang Wu, Bing Hu
The crystal structure of the title polymer, {[Zn(C8H4O6S)(C10H8N2S)(H2O)]·0.26H2O} n , is characterized by a layered arrangement parallel to the ab plane. The zinc cation is five-coordinated in a slightly distorted trigonal-bipyramidal coordination environment defined by two pyridine ligands, two carboxyl-ate groups of two thio-phene di-carboxyl-ate ligands, and by one water mol-ecule. The ethyl-ene bridge in the dioxine ligand is disordered over two sets of sites [occupancy ratio 0.624 (9):0.376 (9)]...
March 1, 2017: Acta Crystallographica. Section E, Crystallographic Communications
https://www.readbyqxmd.com/read/28316804/synthesis-and-structure-of-the-mercury-chloride-complex-of-2-2-2-bromo-5-tert-butyl-1-3-phenyl-ene-bis-1-methyl-1h-benzimidazole
#16
Varsha Rani, Harkesh B Singh, Ray J Butcher
In the title mercury complex, catena-poly[[di-chlorido-mercury(II)]-μ-2,2'-(2-bromo-5-tert-butyl-1,3-phenyl-ene)bis-(1-methyl-1H-benzimidazole)-κ(2)N(3):N(3')], [HgCl2(C26H25BrN4)] n , the Hg(II) atom is coordinated by two Cl atoms and by two N atoms from two 2,2'-(2-bromo-5-tert-butyl-1,3-phenyl-ene)bis-(1-methyl-1H-benzimidazole) ligands. The metal cation adopts a distorted tetrahedral coordination geometry with with bond angles around mercury of 100.59 (15)° [N-Hg-N] and 126.35 (7)° [Cl-Hg-Cl]. This arrangement gives rise to a zigzag helical 1-D polymer propagating along the b-axis direction...
March 1, 2017: Acta Crystallographica. Section E, Crystallographic Communications
https://www.readbyqxmd.com/read/28314988/polymeric-micelles-as-mighty-nanocarriers-for-cancer-gene-therapy-a-review
#17
REVIEW
Mahsa Yousefpour Marzbali, Ahmad Yari Khosroushahi
PURPOSE: Gene therapy has shown extensive potential to treat human diseases occurring from the defection of genes like various types of cancers. The cationic polymers, as non-viral gene carriers, offer the ability to engineer carrier systems having customized features that can be adapted to suit any system. Upon polymeric micelle systems' core-shell structure, micelles can create the capacity to load genes/gene-drugs into the different micelle compartments, respectively. METHODS: The search will be managed in Pubmed, Medline, Cochrane library, Embase and Proquest for articles related to polymeric micelle-based gene delivery in order to cancer gene therapy using the accommodative search terms...
March 17, 2017: Cancer Chemotherapy and Pharmacology
https://www.readbyqxmd.com/read/28314144/hydrophobicity-and-polymer-compatibility-of-poss-modified-wyoming-na-montmorillonite-for-developing-polymer-clay-nanocomposites
#18
Rustam Hojiyev, Yusuf Ulcay, Mirabbos Hojamberdiev, Mehmet S Çelik, William M Carty
The aim of the present work was to investigate the hydrophobicity and polymer compatibility of aminopropylisooctyl polyhedral oligomeric silsequioxane (POSS) - modified Na-montmorillonite (Na-MMT) towards developing polymer-clay nanocomposites. The effect of different concentrations of POSS on properties of Na-MMT was studied. The intercalation ability of the POSS molecules into the Na-MMT interlayer was analyzed by X-ray diffraction. It was found that the d001 value was increased with increasing the POSS concentration, indicating the successful intercalation of the POSS molecules into the Na-MMT interlayer...
July 1, 2017: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/28303896/phospholipid-imprinted-polymers-as-selective-endotoxin-scavengers
#19
Robert Sulc, Gyorgy Szekely, Sudhirkumar Shinde, Celina Wierzbicka, Filipe Vilela, David Bauer, Börje Sellergren
Herein we explore phospholipid imprinting as a means to design receptors for complex glycolipids comprising the toxic lipopolysaccharide endotoxin. A series of polymerizable bis-imidazolium and urea hosts were evaluated as cationic and neutral hosts for phosphates and phosphonates, the latter used as mimics of the phospholipid head groups. The bis-imidazolium hosts interacted with the guests in a cooperative manner leading to the presence of tight and well defined 1:2 ternary complexes. Optimized monomer combinations were subsequently used for imprinting of phosphatidic acid as an endotoxin dummy template...
March 17, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28301829/ionic-crosslinking-of-imidazolium-functionalized-poly-aryl-ether-ketone-by-sulfonated-poly-ether-ether-ketone-for-anion-exchange-membranes
#20
Yixin Xu, Niya Ye, Dengji Zhang, Jingshuai Yang, Ronghuan He
Two N3-substituted imidazoles 1,2-dimethylimidazole and 1-butyl-2-methylimidazole were chosen to functionalize poly(aryl ether ketone), respectively. The generated imidazolium cations could electrostatically react with sulfonate ions of the sulfonated poly(ether ether ketone) forming the ionic crosslinking structure of the membranes. The changes in crosslinking degree and the alkyl chain-length on N3 site of the imidazoliums could highly affect the properties of the anion exchange membranes (AEMs). The AEMs functionalized by 1-butyl-2-methylimidazole exhibited superior properties compared to those functionalized by 1,2-dimethylimidazole according to the tolerance tests of the AEMs towards hot alkaline solutions...
July 1, 2017: Journal of Colloid and Interface Science
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