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Wang, X., Wang, C., Shen, X., Larsson, K. & Sun, F. (2019). DFT calculations of energetic stability and geometry of O-terminated B- and N-doped diamond (111)-1 x 1 surfaces. Journal of Physics: Condensed Matter, 31(26), Article ID 265002.
Open this publication in new window or tab >>DFT calculations of energetic stability and geometry of O-terminated B- and N-doped diamond (111)-1 x 1 surfaces
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2019 (English)In: Journal of Physics: Condensed Matter, ISSN 0953-8984, E-ISSN 1361-648X, Vol. 31, no 26, article id 265002Article in journal (Refereed) Published
Abstract [en]

The non- and O-terminated diamond (1 1 1)-1 x 1 surfaces, with the substitutional B (or N) dopants in different atomic layers, have been modelled in the present study. The influences of the O adsorbates, dopant and dopant position on the adsorption energy, have been studied by performing the density functional theory (DM) calculations. Various parameters were additionally calculated in order to analyze the obtained results: bond lengths, total electron densities, bond populations, atomic charges, Fukui functions (FFs) and density-of-states. Dangling bonds on non-terminated surfaces, O adsorbates, as well as dopants within various atomic layers were all found to induce local effects. In fact, the degree of influences of the dopant on the adsorption energy of the O adsorbates, as well as on parameters like the near-surface bond lengths, total electron density, bond populations and atomic charges, were all found to be dependent on the dopant position. More generally, the deeper the dopant position, the less influence it had on the surface structures and properties. The influences by the dopant in the 1st or 2nd C atomic layer were observed to be significant, but those in the 3rd to 5th C layers were almost negligible. It was also found that the B dopant would decrease the adsorption energy of the adjacent O adsorbates, while the N dopant in the 2nd layer would increase it. Furthermore, the combination of the O adsorbates, together with the dopants within the 1st or 2nd C layer, could induce significant elongation of the bonds between neighboring atoms within the 1st and 2nd layers (i.e. C-C, C-B or C-N bonds). Moreover, all the terminating O atoms could react strongly with either the electrophilic or the nucleophilic species.

Place, publisher, year, edition, pages
IOP PUBLISHING LTD, 2019
Keywords
diamond film, oxygen adsorption, boron doping, nitrogen doping, adsorption energy, surface geometry
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:uu:diva-383468 (URN)10.1088/1361-648X/ab152f (DOI)000465886600002 ()30933937 (PubMedID)
Available from: 2019-05-20 Created: 2019-05-20 Last updated: 2019-05-20Bibliographically approved
Tian, Y. & Larsson, K. (2019). Effect by diamond surface modification on biomolecular adhesion. Materials, 12(6), Article ID 865.
Open this publication in new window or tab >>Effect by diamond surface modification on biomolecular adhesion
2019 (English)In: Materials, ISSN 1996-1944, E-ISSN 1996-1944, Vol. 12, no 6, article id 865Article in journal (Refereed) Published
Abstract [en]

Diamond, as material, show very attractive properties. They include superior electronic properties (when doped), chemical inertness, controllable surface termination, and biocompatibility. It is thus clear that surface termination is very important for those applications where the implant material is based on diamond. The present theoretical work has focused on the effect of diamond surface termination, in combination with type of surface plane, on the adhesion of important biomolecules for vascularization and bone regeneration. These biomolecules include Arginine-Glycine-Aspartic acid (RGD), Chitosan, Heparin, Bone Morphogenetic Protein 2 (BMP2), Angiopoietin 1 (AGP1), Fibronectin and Vascular Endothelial Growth Factor (VEGF). The various surface planes are diamond diamond (100)-2x1 and (111). The theoretical results show that the non-covalent binding of these biomolecules is in proportion with their molecular weights. Moreover, three groups of biomolecules were observed for both types of surface planes. The most strongly binding biomolecule was the BMP2 molecule. The smaller polypeptides (RGD, Chitosan and Heparin) formed a less strongly binding group. Finally, the biomolecules VEGF, Fibronectin and Angiopoietin showed bond strengths numerically in between the other two groups (thereby forming a third group). Moreover, the (111) surface was generally observed to display a stronger bonding of the biomolecules, as compared with the (100)-2x1 surface.

Keywords
Diamond; Theory; Biomolecules
National Category
Manufacturing, Surface and Joining Technology Medical Materials
Research subject
Chemistry with specialization in Materials Chemistry
Identifiers
urn:nbn:se:uu:diva-236954 (URN)10.3390/ma12060865 (DOI)000464362100016 ()30875868 (PubMedID)
Projects
Vascubone
Funder
EU, FP7, Seventh Framework Programme, 242175
Note

Title in thesis list of papers: Effect of diamond surface modification by biomolecular adhesion – a quantum mechanical study

Available from: 2014-11-25 Created: 2014-11-25 Last updated: 2019-05-09Bibliographically approved
Tian, Y. & Larsson, K. (2019). Process of Diamond Surface Termination by Carboxylic and Amino groups: A Quantum Mechanics Approach. Journal of Material Sciences & Engineering, 8(1), Article ID 506.
Open this publication in new window or tab >>Process of Diamond Surface Termination by Carboxylic and Amino groups: A Quantum Mechanics Approach
2019 (English)In: Journal of Material Sciences & Engineering, ISSN 2169-0022, Vol. 8, no 1, article id 506Article in journal (Refereed) Published
Abstract [en]

The main goal with the present work has been to study the possibility and thermodynamical stability for a sequential termination with either carboxylic groups (COOH), or amino groups (NH2), from an initially H-terminated diamond (111), or diamond (100)-2x1 surface. When sequentially substituting the H species with COOH groups, the total energy of adsorption onto the diamond (100)-2x1 surface was observed to drop from -5.45 eV (6.25%) to -26.22 eV (50%).  It was not possible to cover the surface with COOH species at a higher surface coverge. For the diamond (111) surface, the corresponding adsorption energy was calculated as -5.10 eV (6.25%) to -20.03 eV (50%). The values in parentheses are the COOH surface coverages. These values show that it is energetically preferable to terminate both types of surface planes to 50%. For NH2, it was observed possible to terminate both types of surface planes up to 100% coverage. The total adsorption energies went from -3.83 eV (6.25%) to -45.84 eV (100%) for the diamond (100)-2x1 surface, and from -3.61 eV (6.25%) to -39.91 eV (100%) for the diamond (111) surface.

In order to follow the individual bond energy variations with variations in surface coverage, the averaged adsorption energies have also been calculated. As expected, the lowest COOH coverage resulted in the energetically most preferable adsorption energies [(-5.45 eV for diamond (100)-2x1, and -5.10 eV for diamond (111)]. The corresponding situation for the NH2 group was identical for the diamond (111) surface only, with the lowest surface leading to the most preferable adsorption situation (-3.61 eV for the first NH2 group). For the situation with diamond (100)-2x1, a continuous decrease in average adsorption energy was obtained when going from the lowest surface energy of 6.25 % (-3.83 eV) up to 43.75% (-3.95 eV). Hence, there is a thermodynamically preference for diamond (100)-2x1 to be terminated with NH2 groups for higher concentration up to 43.75%.

Partial Density of States were calculated with the purpose to analyse the COOH-induced surface electronic properties, The results showed that NH2 groups will contribute to the shift of the LUMO or HOMO energy levels. As a result, this will lead to a decrease in the HOMO-LUMO gaps, being valid for both diamond surface planes. Moreover, partially filled states were observed in the HOMO-LUMO gaps for COOH-terminated diamond (100)-2x1 surface, as well as for both COOH- and NH2-terminated diamond (111) surfaces. These specific types of surface terminations thereby display surface conductivities, which were not observed for 100% H-terminated surfaces. 

Keywords
Carboxylic, Amino, Theory, Diamond
National Category
Materials Engineering Materials Chemistry
Research subject
Chemistry with specialization in Materials Chemistry
Identifiers
urn:nbn:se:uu:diva-236956 (URN)10.4172/2169-0022.1000506 (DOI)
Projects
Vascubone
Funder
EU, FP7, Seventh Framework Programme, 242175
Available from: 2014-11-25 Created: 2014-11-25 Last updated: 2019-03-21Bibliographically approved
Choudhury, S., Kiendl, B., Ren, J., Gao, F., Knittel, P., Nebel, C., . . . Petit, T. (2018). Combining nanostructuration with boron doping to alter sub band gap acceptor states in diamond materials. Journal of Materials Chemistry A, 6(34), 16645-16654
Open this publication in new window or tab >>Combining nanostructuration with boron doping to alter sub band gap acceptor states in diamond materials
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2018 (English)In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 6, no 34, p. 16645-16654Article in journal (Refereed) Published
Abstract [en]

Diamond is a promising metal-free photocatalyst for nitrogen and carbon dioxide reduction in aqueous environment owing to the possibility of emitting highly reducing solvated electrons. However, the wide band gap of diamond necessitates the use of deep UV to trigger a photochemical reaction. Boron doping introduces acceptor levels within the band gap of diamonds, which may facilitate visible-light absorption through defect-based transitions. In this work, unoccupied electronic states from different boron-doped diamond materials, including single crystal, polycrystalline film, diamond foam, and nanodiamonds were probed by soft X-ray absorption spectroscopy at the carbon K edge. Supported by density functional theory calculations, we demonstrate that boron close to the surfaces of diamond crystallites induce acceptor levels in the band gap, which are dependent on the diamond morphology. Combining boron-doping with morphology engineering, this work thus demonstrates that electron acceptor states within the diamond band gap can be controlled.

Place, publisher, year, edition, pages
ROYAL SOC CHEMISTRY, 2018
National Category
Materials Chemistry
Identifiers
urn:nbn:se:uu:diva-366740 (URN)10.1039/c8ta05594g (DOI)000444698200040 ()
Funder
EU, Horizon 2020, 665085
Available from: 2018-12-10 Created: 2018-12-10 Last updated: 2018-12-10Bibliographically approved
Larsson, K. (2018). Effect of diamond surface modification by biomolecular adhesion – a quantum mechanical study. In: Novel Aspects of Diamond: . Springer
Open this publication in new window or tab >>Effect of diamond surface modification by biomolecular adhesion – a quantum mechanical study
2018 (English)In: Novel Aspects of Diamond, Springer, 2018Chapter in book (Refereed)
Place, publisher, year, edition, pages
Springer, 2018
National Category
Natural Sciences
Research subject
Chemistry with specialization in Inorganic Chemistry
Identifiers
urn:nbn:se:uu:diva-371897 (URN)
Available from: 2019-01-02 Created: 2019-01-02 Last updated: 2019-01-02
Larsson, K. & Tian, Y. (2018). Effect of surface termination on the reactivity of nano-sized diamond particle surfaces for bio applications. Carbon, 134, 244-254
Open this publication in new window or tab >>Effect of surface termination on the reactivity of nano-sized diamond particle surfaces for bio applications
2018 (English)In: Carbon, ISSN 0008-6223, E-ISSN 1873-3891, Vol. 134, p. 244-254Article in journal (Other academic) Published
Abstract [en]

Nanodiamond has displayed some unique physical and chemical properties compared to bulk diamond, which broadens its applications invarious areas. The here presented investigations have focused on the combined effect of diamond surface planes and termination on surface reactivity. Then especially towards adhered important biomolecules for bone regeneration and vascularization. Moreover, a more detailed picture of nanodiamond quantum confinements is still missing from a theoretical point of view. An evaluation of realistic models for nano-diamond (ND) particles of various sizes will here be presented. In addition, the adhesions of various biomolecules, both in vacuum and in a liquid environment, as a function of surface plane and termination, will also be presented. It was shown possible to model nanodiamond particles of size larger than 2 nm with (100) and (111) surface planes. For the situation with biomolecule adhesion to the nanodiamond surfaces, there is a large similarity between the results for the diamond (111) and (100)-2x1surfaces. For both of these surfaces, even though the water solvation will create much stronger biomolecular adhesion energies, there is a resemblance in order of adhesion energy for the various systems (i.e., solvated vs. non-solvated).

Place, publisher, year, edition, pages
Elsevier, 2018
National Category
Inorganic Chemistry
Identifiers
urn:nbn:se:uu:diva-338642 (URN)10.1016/j.carbon.2018.03.031 (DOI)000433244900027 ()
Funder
EU, FP7, Seventh Framework Programme, 242175
Available from: 2018-01-11 Created: 2018-01-11 Last updated: 2018-08-24Bibliographically approved
Larsson, K., Stutzmann, M. & Hetzl, M. (2018). Polarity Control of GaN Nanowires on Diamond:  Experiment and Theory. In: : . Paper presented at AVS65-conference in Long Beach, California, USA.
Open this publication in new window or tab >>Polarity Control of GaN Nanowires on Diamond:  Experiment and Theory
2018 (English)Conference paper, Oral presentation with published abstract (Other academic)
National Category
Natural Sciences
Identifiers
urn:nbn:se:uu:diva-371898 (URN)
Conference
AVS65-conference in Long Beach, California, USA
Available from: 2019-01-02 Created: 2019-01-02 Last updated: 2019-01-02
Choudhury, S., Petit, T., Ren, J., Kiendl, B., Gao, F., Nebel, C., . . . Aziz, E. (2017). Altering Mid-Gap Acceptor Levels by Morphology Tuning of Boron Doped Diamonds. In: : . Paper presented at 2017 MRS Fall Meeting & Exhibit, November 26-December 1, 2017 Boston, Massachusetts, USA.
Open this publication in new window or tab >>Altering Mid-Gap Acceptor Levels by Morphology Tuning of Boron Doped Diamonds
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2017 (English)Conference paper, Oral presentation with published abstract (Other academic)
Abstract [en]

Hydrogen terminated diamond is a very promising material for high energy photocatalytic reactions1 owing to its large band gap(5.5 eV) and a unique capability of generating solvated electrons due to its negative electron affinity.2 However, a major limitation to the photoexcitation process to create solvated electrons is the need for deep UV illumination. Introducing unoccupied electronic states within the band gap of diamonds by doping with boron could provide a potential pathway for photoexcitation using visible light.Previous reports on HRTEM and EELS study of B doped polycrystalline and nanocrystalline diamonds provide insights into the local B environment.4,5,6,7 However, since these are primarily electron in-electron out techniques, they do not provide sufficient information about the existence of acceptor levels in the band gap of diamonds that are associated with boron doping. X-ray spectroscopy techniques have been shown to be sensitive to the acceptor levels arising due to boron doping.3 However, their physical origin still remains unclear.Here we use soft X-ray absorption spectroscopy (XAS) to probe the unoccupied electronic states at the carbon K edge in different boron-doped diamond materials, ranging from single crystal and polycrystalline film to diamond foam and nanodiamonds with different sizes. XAS of carbon K edges for the different B doped diamonds were characterized using partial fluorescence yield at the BESSY II synchrotron facility. Combining these results with density functional theory calculations, here we elucidate the contribution of the environment of boron to these mid gap acceptor states that vary with the morphology of diamonds. These results could have important implications on the selection of a suitable diamond based visible-light photocatalysts.

National Category
Inorganic Chemistry
Identifiers
urn:nbn:se:uu:diva-338640 (URN)
Conference
2017 MRS Fall Meeting & Exhibit, November 26-December 1, 2017 Boston, Massachusetts, USA
Note

Symposium session EM06 : Diamond Electronics, Sensors and Biotechnology—Fundamentals to Applications

EM06.14.02

Available from: 2018-01-11 Created: 2018-01-11 Last updated: 2018-02-16Bibliographically approved
Wu, X., Bruschi, M., Waag, T., Schweeberg, S., Tian, Y., Meinhardt, T., . . . Krueger, A. (2017). Functionalization of bone implants with nanodiamond particles and angiopoietin-1 to improve vascularization and bone regeneration. Journal of materials chemistry. B, 5(32), 6629-6636
Open this publication in new window or tab >>Functionalization of bone implants with nanodiamond particles and angiopoietin-1 to improve vascularization and bone regeneration
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2017 (English)In: Journal of materials chemistry. B, ISSN 2050-750X, E-ISSN 2050-7518, Vol. 5, no 32, p. 6629-6636Article in journal (Refereed) Published
Abstract [en]

One of the major challenges in bone tissue engineering is adequate vascularization within bone substituents for nutrients and oxygen supply. In this study, the production and results of a new, highly functional bone construct consisting of a commercial three-dimensional beta-tricalcium phosphate scaffold (beta-TCP, ChronOS (R)) and hydrophilic, functionalized nanodiamond (ND) particles are reported. A 30-fold increase in the active surface area of the ChronOS + ND scaffold was achieved after modification with ND. In addition, immobilization of angiopoietin-1 (Ang-1) via physisorption within the beta-TCP + ND scaffold retained the bioactivity of the growth factor. Homogeneous distribution of the ND and Ang-1 within the core of the three-dimensional scaffold was confirmed using ND covalently labelled with Oregon Green. The biological responses of the beta-TCP + ND scaffold with and without Ang-1 were studied in a sheep calvaria critical size defect model showing that the beta-TCP + ND scaffold improved the blood vessel ingrowth and the beta-TCP + ND + ND + Ang-1 scaffold further promoted vascularization and new bone formation. The results demonstrate that the modification of scaffolds with tailored diamond nanoparticles is a valuable method for improving the characteristics of bone implants and enables new approaches in bone tissue engineering.

National Category
Materials Chemistry
Identifiers
urn:nbn:se:uu:diva-333753 (URN)10.1039/c7tb00723j (DOI)000407684800019 ()
Available from: 2017-11-16 Created: 2017-11-16 Last updated: 2017-11-16Bibliographically approved
Choudhury, S., Petit, T., Ren, J., Kiendl, B., Gao, F., Nebel, C., . . . Aziz, E. (2017). Influence of size on boron acceptor levels in boron doped diamonds: An X-ray absorption spectroscopy study. In: : . Paper presented at Hasselt Diamond Workshop 2017 - SBDD XXII.
Open this publication in new window or tab >>Influence of size on boron acceptor levels in boron doped diamonds: An X-ray absorption spectroscopy study
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2017 (English)Conference paper, Poster (with or without abstract) (Other academic)
National Category
Inorganic Chemistry
Identifiers
urn:nbn:se:uu:diva-338638 (URN)
Conference
Hasselt Diamond Workshop 2017 - SBDD XXII
Available from: 2018-01-11 Created: 2018-01-11 Last updated: 2018-01-11
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-4156-9442

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