Combined effect of ion concentration and functional groups on surface chemistry modulated CaCO3 crystallization

CrystEngComm ◽  
2012 ◽  
Vol 14 (20) ◽  
pp. 6647 ◽  
Author(s):  
Hua Deng ◽  
Xiu-Mei Wang ◽  
Chang Du ◽  
Xing-Can Shen ◽  
Fu-Zhai Cui
Keyword(s):  
Surface Chemistry ◽  
Functional Groups ◽  
Combined Effect ◽  
Ion Concentration

Manufacturing a nanometre scale surface topography with varying surface chemistry to assess the combined effect on cell behaviour

2008 ◽  
Vol 1 (3) ◽  
pp. 320 ◽  
Author(s):  
Brian G. Cousins ◽  
Jurgita Zekonyte ◽  
Patrick J. Doherty ◽  
Michael J. Garvey ◽  
Rachel L. Williams
Keyword(s):  
Surface Chemistry ◽  
Surface Topography ◽  
Combined Effect ◽  
Cell Behaviour ◽  
Scale Surface

Surface Modification of a-C:H(N) Thin Films by Plasma Treatment

2005 ◽  
Vol 11 (S03) ◽  
pp. 162-165 ◽  
Author(s):  
L. von Mühlen ◽  
R. A. Simao ◽  
C. A. Achete
Keyword(s):  
Thin Films ◽  
Surface Roughness ◽  
Optical Properties ◽  
Surface Modification ◽  
Surface Chemistry ◽  
Plasma Treatment ◽  
Surface Properties ◽  
Functional Groups ◽  
Material Properties ◽  
Modify Surface

Surface chemistry and topography of materials are generally preponderant factors in a series of material properties, such as adhesion, wettability, friction and optical properties [1]. Wettability of films, for example, can be altered significantly by modifying its surface roughness and also by incorporating functional groups. Plasma treatment is a powerful and versatile way to modify surface properties of amorphous nitrogen-incorporated carbon thin films (a-C:H(N)) and obtain materials with improved properties, once it is possible to modify the surfaces in a controlled way by specific settings of plasma conditions. [2 - 4]

Impact of pH on CdII partitioning between alginate gel and aqueous media

2009 ◽  
Vol 6 (4) ◽  
pp. 305 ◽  
Author(s):  
Erwin J. J. Kalis ◽  
Thomas A. Davis ◽  
Raewyn M. Town ◽  
Herman P. van Leeuwen
Keyword(s):  
Functional Groups ◽  
Metal Ion ◽  
Ion Concentration ◽  
Local Concentration ◽  
Relevant Parameter ◽  
Donnan Potential ◽  
Alginate Gel ◽  
Bulk Medium ◽  
Ph Dependent

Environmental context. Biogels, such as those in cell walls or biofilm matrices, generally comprise negative structural charge which leads to accumulation of positively charged species, e.g. metal ions. The magnitude of the effective charge, and hence the local chemical speciation within the gel phase, is pH dependent. In situ speciation measurements in biogels, such as the model alginate studied in this work, offer a better estimate of bioavailable concentrations than does analysis of the surrounding aqueous medium. Abstract. Many microorganisms exist in a biogel-mediated micro-environment such as a cell wall or a biofilm, in which local concentrations of ionic nutrients and pollutants differ from those in the surrounding bulk medium. The local concentration is the relevant parameter for considerations of bioavailability. These modified concentrations arise as a consequence of the negative charges within biogels which may induce a Donnan potential inside the biogel phase. For metals, the net effect on the speciation within the biogel, relative to the bulk medium, is an enhancement of the concentration of free cations. Since the structural charge in the biogel arises from protolytic functional groups, the Donnan potential is pH dependent. Here we apply in situ voltammetry to measure the free metal ion concentration inside alginate gel as a function of pH. In the pH range 3 to 7, the speciation of CdII within this model biogel can be explained by specific binding to carboxylic functional groups and electrostatic binding resulting from the Donnan potential.

Surface Properties of Carbon

1971 ◽  
Vol 44 (2) ◽  
pp. 307-343 ◽  
Author(s):  
Donald Rivin
Keyword(s):  
Carbon Black ◽  
Surface Chemistry ◽  
Functional Groups ◽  
Surface Reactivity ◽  
Point Of View ◽  
Background Information ◽  
Carbon Surface ◽  
Functional Behavior ◽  
Defect Sites

Abstract Carbon surface chemistry is relatively new as an independent subject of inquiry, and, judging by the volume of publications, is receiving increasing attention throughout the world. Our conception of carbon black and its functional behavior has changed significantly since the pioneering publication by Studebaker in 1957. Within the last few years there have been a number of excellent reviews covering various aspects of carbon chemistry by authors who are presently active in this field. Donnet, Puri, and Boehm discuss reactions of carbon and the characterization of surface functional groups while van der Plas is particularly thorough on the subject of adsorption properties and porosity. Deviney explores the relationship between surface chemistry and carbon-elastomer interactions, as does Studebaker from the point of view of the practical application of carbon black in rubber. Current monographs containing useful background information are collected in “Les Carbones” and in Walker's continuing series, “Chemistry and Physics of Carbon”. This review will describe how information from diverse sources has contributed to our understanding of the surface reactivity and fundamental adsorption behavior of carbon. It will be shown that most properties of carbon blacks are consistent with a surface structure wherein large deformed basal layers conforming to the topography of the surface are composed of several planar aromatic domains with functional groups at edge and defect sites. Examples of strong molecular interactions are given which involve specific reaction with the basal surface, individual functional groups, or a combination of both.

scholarly journals Adsorption of Pb(II) and Cd(II) by SquidOmmastrephes bartramiMelanin

2009 ◽  
Vol 2009 ◽  
pp. 1-7 ◽  
Author(s):  
Shiguo Chen ◽  
Changhu Xue ◽  
Jingfeng Wang ◽  
Hui Feng ◽  
Yuming Wang ◽  
...  
Keyword(s):  
Functional Groups ◽  
Metal Binding ◽  
Metal Ion ◽  
Ion Concentration ◽  
Obvious Effect ◽  
Removal Of Heavy Metals ◽  
New Material ◽  
Amine Groups ◽  
Ir Analysis ◽  
Ph Range

The adsorption of Cd(II) and Pb(II) by squid melanin was investigated. At a metal ion concentration of 2 mM/L, the biosorption efficiency of melanin reached 95% for Cd(II) and Pb(II). The maximum content of bound Cd(II) and Pb(II) was 0.93 mM/g and 0.65 mM/g, respectively. Temperature had no obvious effect on the adsorption of the metals, and in a pH range of 4.0–7.0, the adsorption yield was high and stable. Macrosalts such as NaCl,MgCl2, andCaCl2had no obvious effect on the binding of Pb(II) but greatly diminished the adsorption of Cd(II), which indicated that different functional groups in squid melanin are responsible for their adsorption. IR analysis of metal ion-enriched squid melanin demonstrated that the possible functional groups responsible for metal binding were phenolic hydroxyl (OH), carboxyl (COOH), and amine groups (NH). This study reports a new material for the removal of heavy metals from low-strength wastewater.

scholarly journals Surface Modification and Characterization of Coconut Shell-Based Activated Carbon Subjected to Acidic and Alkaline Treatments

2017 ◽  
Vol 4 (2) ◽  
pp. 186-194 ◽  
Author(s):  
Tan I. A. W. ◽  
Abdullah M. O. ◽  
Lim L. L. P. ◽  
Yeo T. H. C.
Keyword(s):  
Activated Carbon ◽  
Surface Morphology ◽  
Surface Chemistry ◽  
Pore Structure ◽  
Surface Area ◽  
Functional Groups ◽  
Activated Carbons ◽  
Coconut Shell ◽  
Bet Surface Area ◽  
Textural Characterization

Activated carbon derived from agricultural biomass has been increasingly recognized as a multifunctional material for various applications according to its physicochemical characteristics. The application of activated carbon in adsorption process mainly depends on the surface chemistry and pore structure which is greatly influenced by the treatment method. This study aims to compare the textural characteristics, surface chemistry and surface morphology of coconut shell-based activated carbon modified using chemical surface treatments with hydrochloric acid (HCl) and sodium hydroxide (NaOH). The untreated and treated activated carbons were characterized for their physical and chemical properties including the Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and textural characterization. The FTIR spectra displayed bands confirming the presence of carboxyl, hydroxyl and carbonyl functional groups. The Brunauer–Emmett–Teller (BET) surface area of the untreated activated carbon was 436 m2/g whereas the surface area of the activated carbon modified using 1M NaOH, 1M HCl and 2M HCl was 346, 525 and 372 m2/g, respectively. SEM micrographs showed that many large pores in a honeycomb shape were clearly found on the surface of 1M HCl sample. The pore structure of the activated carbon treated with 2M HCl and NaOH was partially destroyed or enlarged, which decreased the BET surface area. The modification of the coconut shell-based activated carbon with acidic and alkaline treatments has successfully altered the surface functional groups, surface morphology and textural properties of the activated carbon which could improve its adsorptive selectivity on a certain adsorbate.

scholarly journals Analyzing the surface of functional nanomaterials—how to quantify the total and derivatizable number of functional groups and ligands

2021 ◽  
Vol 188 (10) ◽  
Author(s):  
Daniel Geißler ◽  
Nithiya Nirmalananthan-Budau ◽  
Lena Scholtz ◽  
Isabella Tavernaro ◽  
Ute Resch-Genger
Keyword(s):  
Surface Chemistry ◽  
Functional Groups ◽  
Analytical Methods ◽  
Production Control ◽  
Analytical Techniques ◽  
First Century ◽  
Covalent Attachment ◽  
Functional Nanomaterials ◽  
Coated Nanoparticles ◽  
And Performance

AbstractFunctional nanomaterials (NM) of different size, shape, chemical composition, and surface chemistry are of increasing relevance for many key technologies of the twenty-first century. This includes polymer and silica or silica-coated nanoparticles (NP) with covalently bound surface groups, semiconductor quantum dots (QD), metal and metal oxide NP, and lanthanide-based NP with coordinatively or electrostatically bound ligands, as well as surface-coated nanostructures like micellar encapsulated NP. The surface chemistry can significantly affect the physicochemical properties of NM, their charge, their processability and performance, as well as their impact on human health and the environment. Thus, analytical methods for the characterization of NM surface chemistry regarding chemical identification, quantification, and accessibility of functional groups (FG) and surface ligands bearing such FG are of increasing importance for quality control of NM synthesis up to nanosafety. Here, we provide an overview of analytical methods for FG analysis and quantification with special emphasis on bioanalytically relevant FG broadly utilized for the covalent attachment of biomolecules like proteins, peptides, and oligonucleotides and address method- and material-related challenges and limitations. Analytical techniques reviewed include electrochemical titration methods, optical assays, nuclear magnetic resonance and vibrational spectroscopy, as well as X-ray based and thermal analysis methods, covering the last 5–10 years. Criteria for method classification and evaluation include the need for a signal-generating label, provision of either the total or derivatizable number of FG, need for expensive instrumentation, and suitability for process and production control during NM synthesis and functionalization. Graphical abstract

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