Speciation of functional groups formed on the surface of ammoxidised carbonaceous materials by XPS method

Tang

J of Applied Polymer Sci

et al. 2016

An antifouling surface is highly desirable for many biomedical applications. In this study, poly(vinyl chloride) (PVC) films were endowed with the improved properties of resisting nonspecific protein adsorption and platelet adhesion simply through being coated with a kind of mixed-charge zwitterionic polymer, poly(3-sulfopropyl methacrylate-methacrylatoethyl trimethyl ammonium chloride-glycidyl methacrylate) (PSTG), with random moieties of negatively charged 3-sulfopropyl methacrylate potassium, positively charged [2-(methacryloyloxy)-ethyl] trimethylammonium chloride, and glycidyl methacrylate. The PSTG-grafted PVC films were formed by the simple immersion of an amino-functionalized PVC film into a PSTG solution. A grafting density of 220.84 mg/cm 2 of PSTG4-grafted PVC film was successfully obtained. The PSTG4-grafted PVC film showed a lower contact angle (37.5 8) than the ungrafted PVC film (98.3 8). The in vitro protein adsorption results show that the bovine serum albumin adsorption amount decreased 6.72 mg/cm 2 in the case of the PSTG4-grafted PVC film, whereas that on the ungrafted PVC film was 28.54 mg/cm 2 . So, PSTG-grafted PVC films could be promising materials for medical devices.

Section: Resultsmentioning

confidence: 99%

One simple and stable coating of mixed‐charge copolymers on poly(vinyl chloride) films to improve antifouling efficiency

Tang

J of Applied Polymer Sci

et al. 2016

The Scientific World Journal

“…Modification by nitrogen reagent was performed by two methods. Ammoxidation (N) was carried out using a mixture of ammonia and air at a volume ratio of 1 : 3 (250/750 mL/min) in a flow reactor at 270°C for 5 h [ 25 – 27 ]. In the process of nitrogenation, the samples were exposed to nitrogen(II) oxide (620 mL/min) in a flow reactor at 300°C for 2 h [ 35 ].…”

Section: Methodsmentioning

confidence: 99%

“…X-ray photoelectron spectroscopy (XPS) and FT-IR/PAS studies of the organic origin samples enriched in nitrogen proved that the chemical character of surface nitrogen groups formed upon ammoxidation differs from those formed as a result of nitrogenation with nitrogen(II) oxide. The nitrogen groups dominant on the surface of the materials subjected to ammoxidation are pyrrole, pyridine, and amine ones [ 26 , 27 ], but when nitrogen(II) oxide was the source of nitrogen, the dominant nitrogen species are amide groups and nitrates [ 35 ]. As follows from the results of our earlier studies, the samples enriched in nitrogen by ammoxidation or nitrogenation differ in the catalytic properties [ 29 – 33 ] and capacities of adsorption from gas phase [ 33 , 34 ], according to the chemical character of the nitrogen species identified on their surface.…”

Section: Introductionmentioning

confidence: 99%

Nitrogen-Doped Carbonaceous Materials for Removal of Phenol from Aqueous Solutions

Hofman

Pietrzak

2012

Self Cite

Carbonaceous material (brown coal) modified by pyrolysis, activation, and enrichment in nitrogen, with two different factor reagents, have been used as adsorbent of phenol from liquid phase. Changes in the phenol content in the test solutions were monitored after subsequent intervals of adsorption with selected adsorbents prepared from organic materials. Significant effect of nitrogen present in the adsorbent material on its adsorption capacity was noted. Sorption capacity of these selected materials was found to depend on the time of use, their surface area, and pore distribution. A conformation to the most well-known adsorption isotherm models, Langmuir, and Freundlich ones, confirms the formation of mono- and heterolayer solute (phenol) coverage on the surface of the adsorbent applied herein. The materials proposed as adsorbents of the aqueous solution contaminants were proved effective, which means that the waste materials considered are promising activated carbon precursors for liquid phase adsorbents for the environmental protection.

Environmental Engineering Research

“…This suggests that the tanning agent-AC interaction would mainly occur through the basic sites. That is, π-d complexes between delocalized π electrons in aromatic structures and cations are formed [19][20][21][22][23][24][25]. According to these results, the Boehm method is considered more effective than the point of zero charge (PZC) measurement to quantify the adsorbent performance [14,25].…”

Section: Removal Of Chromium(iii)mentioning

confidence: 99%

“…In AC, the removal is described by two mechanisms; the most widely known comprises an ion exchange on acid sites (carboxyl, lactone and lactol groups). The other is the product of the reaction between the negatively charged surface (delocalized π electrons in aromatic structures) and cations, forming π-d complexes [19][20][21][22][23][24][25]. This adsorbent is used to remove toxic materials dissolved in an aqueous medium, which is the reason why it was chosen for the present study [6,8,14,19,20,22,26].…”

Section: Introductionmentioning

confidence: 99%

Chromium(III) recovery from tanning wastewater by adsorption on activated carbon and elution with sulfuric acid

Hintermeyer

Tavani

2016

Chromium(III) recovery from tanning wastewater by means of adsorption on activated carbon and elution with sulfuric acid was studied. Tests were carried out at laboratory scale on an effluent of industrial origin. Initially, proteinaceous materials and fats were separated via sieving followed by ultrafiltration. The chemical composition of the sample thus precleansed was (in g/L): 1.09 chromium(III); 10.36 sulfate; 11.10 sodium; 9.57 chloride; 0.40 proteinaceous materials; and 0.20 fats. Adsorptions were made at 20, 30, and 40°C, establishing what temperature favored chromium(III) uptake. At 40°C, the maximum cation fixation was 40.2 mg/g, and the lowest content in an equilibrium solution was 3.9 mg/L. As regards sodium, chloride, and sulfate, the concentrations before and after the treatment were similar. Likewise, it was found that protons were also retained, modifying the pH of the liquid medium. Adsorption isotherms were analyzed using the Langmuir, Temkin, and Freundlich models. Finally, the extraction of the adsorbed tanning agent with sulfuric acid was evaluated. A recovery of 96.5% was achieved with 0.9 N at 70°C (13.23 g/L Cr 3+ ; 42.98 g/L sulfate; and 0.40 g/L NaCl).