Plasma Immersion Ion Implantation And Deposition Research Articles

Incorporating zinc ion into titanium surface promotes osteogenesis and osteointegration in implantation early phase

The objective of this study is to further investigate the feasibility of Zinc–Titanium implant as a potential implantable material in oral application in aspects of osteoblast biocompatibility, osteogenesis and osseointegration ability. First, we used plasma immersion ion implantation and deposition (PIIID) technology to introduce Zinc ion into pure Titanium surface, then we used X-ray photoelectron spectroscopy to analyze the chemical composition of modified surface layer; next, we used in vitro studies including immunological fluorescence assay and western blotting to determine responses between MG-63 osteoblast-like cell and implant. In vivo studies adopted pig model to check the feasibility of Zn–Ti implant. Results showed that in vitro and in vivo were consistent, showing that Zn ion was successfully introduced into Ti surface by PIIID technique. The chemical and physical change on modified plant resulted in the more active expressions of mRNA and protein of Type I collagen in MG-63 cells compared with non-treated implant, and the better integration ability of bones with modified implant. We confirmed the Zn–Ti implant owns the ability in promoting osteogenesis and osteointegration in early phase of implantation and is a qualified candidate in dentistry. The overview of our study can be depicted as follows.Graphical

Self-bonding of semi-crystalline PEEK by nano thin film polymer coatings facilitated by multiple plasma depositions

Self-bonding of PEEK is an enabling process for the use of PEEK for devices that require hermetic seals such as active medical implants. Self-bonding of semi-crystalline polyether ether ketone (PEEK) has been successfully demonstrated through plasma immersion ion implantation and deposition (PIIID) treatment. The surface properties, such as wetting property, free energy, and roughness, of PEEK that influence the adhesive strength are manipulated according to the ionization power and excitation reactivity of the plasma gas implemented in the treatment. Temperature, one of the self-bonding process condition parameters, is a factor influencing the functionalities of the plasma gas. In general, the combinations of plasma gases, C2H2, CH4, and O2, were capable of achieving at least fivefold adhesive strengths of PEEKs with only CH4 plasma gas showing a negative response. Single O2/CH4- and C2H2-PIIID plasma treatments performed effectively in enhancing the adhesive strength of PEEK with almost eightfold compared to untreated control while double C2H2/O2+O2/CH4-PIIID/PIIID plasma treatment obtained an equivalent achievement.

Silicon Oxide‐Rich Diamond‐Like Carbon: A Conformal, Ultrasmooth Thin Film Material with High Thermo‐Oxidative Stability

AbstractSilicon oxide‐containing diamond‐like carbon (a‐C:H:Si:O) films are a promising class of protective coatings for environmentally‐demanding applications owing to their lower residual stresses and superior thermal stability and oxidation resistance relative to undoped diamond‐like carbon. However, existing versions of a‐C:H:Si:O deposited by traditional methods such as plasma‐enhanced chemical vapor deposition (PECVD) undergo substantial degradation and oxidation at temperatures above 250 °C. This, together with the difficulty of PECVD in depositing conformal coatings on complex geometries such as high‐aspect‐ratio features, has limited the applicability of a‐C:H:Si:O. Here, the unique capabilities of plasma immersion ion implantation and deposition (PIIID) to grow silicon oxide‐rich diamond‐like carbon materials that are ultrasmooth, continuous, and conformal on high‐aspect‐ratio topographies are explored. The high concentration of silicon and oxygen in PIIID‐grown films (23 ± 5 at.% and 11 ± 4 at.%, respectively) is unrivalled for this class of materials, and drastically increases the resistance to oxidation at high temperatures, compared with PECVD‐grown films. The results open the path for using a‐C:H:Si:O in applications involving exposure of materials to extreme environments.

Cellular Response of Human Bone Marrow Derived Mesenchymal Stem Cells to Titanium Surfaces Implanted with Calcium and Magnesium Ions.

Surface characteristics and cellular response to titanium surfaces that had been implanted with calcium and magnesium ions using plasma immersion ion implantation and deposition (PIIID) were evaluated. Three different titanium surfaces were analyzed: a resorbable blast media (RBM) surface (blasted with hydroxyapatite grit), a calcium ion-implanted surface, and a magnesium ion-implanted surface. The surface characteristics were investigated by scanning electron microscopy (SEM), surface roughness testing, X-ray diffraction (XRD), and Auger electron spectroscopy (AES). Human bone marrow derived mesenchymal stem cells were cultured on the 3 different surfaces. Initial cell attachment was evaluated by SEM, and cell proliferation was determined using MTT assay. Real-time polymerase chain reaction (PCR) was used to quantify osteoblastic gene expression (i.e., genes encoding RUNX2, type I collagen, alkaline phosphatase, and osteocalcin). Surface analysis did not reveal any changes in surface topography after ion implantation. AES revealed that magnesium ions were present in deeper layers than calcium ions. The calcium ion- and magnesium ion-implanted surfaces showed greater initial cell attachment. Investigation of cell proliferation revealed no significant difference among the groups. After 6 days of cultivation, the expression of RUNX2 was higher in the magnesium ion-implanted surface and the expression of osteocalcin was lower in the calcium ion-implanted surface. In conclusion, ion implantation using the PIIID technique changed the surface chemistry without changing the topography. Calcium ion- and magnesium ion-implanted surfaces showed greater initial cellular attachment.

Tribocorrosion Failure Mechanism of TiN/SiOx Duplex Coating Deposited on AISI304 Stainless Steel.

TiN/SiOx duplex coatings were synthesized on AISI304 stainless steel by plasma immersion ion implantation and deposition (PIIID) followed by radio frequency magnetron sputtering (RFMS). The microstructure and tribocorrosion failure behaviors of the duplex coatings were investigated by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, atomic force microscopy, reciprocating-sliding tribometer, and electrochemical tests. The as-deposited duplex coating had a two-layered columnar growth structure consisting of face-centered cubic TiN and amorphous SiOx. Sliding tests showed that the TiN interlayer had good adhesion with the substrate, but the SiOx layer suffered from severe delamination failure. Friction force induced a number of micro-cracks in the coating, which provided channels for the diffusion of NaCl solution. The tribocorrosion test showed that the duplex coating exhibited a lower wear-performance in NaCl solution than in ambient atmosphere. Multi-scale chloride ion corrosion occurred simultaneously and substantially degraded the bonding strength of the columnar crystals or neighboring layers. Force-corrosion synergy damage eventually led to multi-degradation failure of the duplex coating. The presented results provide a comprehensive understanding of the tribocorrosion failure mechanism in coatings with duplex architecture.

Bioactive (Si, O, N)/(Ti, O, N)/Ti composite coating on NiTi shape memory alloy for enhanced wear and corrosion performance

In this investigation, (Si, O, N)/(Ti, O, N)/Ti composite coating was synthesized on a NiTi shape memory alloy (SMA) substrate (50.8at.% Ni) via plasma immersion ion implantation and deposition (PIIID) followed by magnetron sputtering, with the aim of promoting bioactivity and biocompatibility of NiTi SMAs. Nano featured (Si, O, N)/(Ti, O, N)/Ti coating was approximate 0.84±0.05μm in thickness, and energy dispersive X-ray (EDX) spectroscopy showed that Ni element was depleted from the surface of coated samples. X-ray diffraction (XRD) did not identify the phase composition of the (Si, O, N)/(Ti, O, N)/Ti coating, probably due to its thin thickness and poor crystalline resulting from low-temperature coating processes (<200°C). X-ray photoelectron spectroscopy (XPS) analyses confirmed that a Ni-free surface was formed and Si element was incorporated into the composite coating via the magnetron sputtering process. Additionally, phase transformation behaviors of uncoated and coated NiTi SMA samples were characterized using differential scanning calorimetry (DSC). Wear and corrosion resistance of uncoated and coated NiTi SMA samples were evaluated using ball-on-disc tests and potentio-dynamic polarization curves, respectively. The (Si, O, N)/(Ti, O, N)/Ti coated NiTi SMA samples showed enhanced wear and corrosion resistance. Furthermore, the (Si, O, N)/(Ti, O, N)/Ti composite coating facilitated apatite formation in simulated body fluid (SBF) and rendered NiTi SMA bioactivity.

The study of composition and surface electron structure of nitrogen-doped DLC film prepared by PIII-D

Nitrogen-doped diamond-like carbon (N-DLC) films were synthesized by plasma immersion ion implantation and deposition (PIII-D) at room temperature (RT). During the process of deposition, N 2 flow was changed from 0 to 10 sccm. Lifshitz–van der Waals/acid–base (LW-AB) approach was employed to study the surface electronic state of the films, X-ray photoelectron spectroscopic (XPS) and valence band spectra (VBS) were used to study chemical bonds and electron structure information inside the films. Bandgap of the films were calculated by the data from ultraviolet spectrophotometer. The results showed that synthesized films were n-type semiconductors and doping of nitrogen element will affect the accepted–electron capability of the film. The change tendency of the bandgap coincides with that of the ratio of acidic to alkaline component of the polar acid-alkali surface energy. There was much sp hybrid electronic state existed in the films, which mainly sp2 C=C / C=N and sp3 C–C / C–N bonds.

Effect of Ion Irradiation on the Structural Properties and Hardness of a-C:H:Si:O:F Films

Amorphous carbon-based thin films, a-C:H:Si:O:F, were obtained by plasma immersion ion implantation and deposition (PIIID) from mixtures of hexamethyldisiloxane, sulfur hexafluoride and argon. For PIIID the sample holder was biased with negative 25 kV pulses at 60 Hz. The main system parameter was the proportion of SF6 in the reactor feed, Rsf. To allow comparison to growth without intentional ion implantation, some films were also grown by plasma enhanced chemical vapor deposition (PECVD). The objectives were to investigate the effects of fluorine incorporation and ion implantation on the film's chemical structure, and principally on the surface contact angle, hardness and friction coefficient. Infrared and X-ray photo-electron spectroscopic analyses revealed that the films are essentially amorphous and polymer-like, and that fluorine is incorporated for any non-zero value of Rsf. Choice of RSF influences film composition and structure but ion implantation also plays a role. Depending on Rsf, hydrophilic or hydrophobic films may be produced. Ion implantation is beneficial while fluorine incorporation is detrimental to hardness. For ion implanted films the friction coefficient falls about one third as Rsf is increased from 0 to 60%. Films prepared by PIIID without fluorine incorporation present fairly low friction coefficients and hardnesses greater than those of conventional polymers.

Ti-O-N/Ti composite coating on Ti-6Al-4V: surface characteristics, corrosion properties and cellular responses.

To enhance the corrosion resistance of Ti-6Al-4V and extend its lifetime in medical applications, Ti-O-N/Ti composite coating was synthesized on the surface via plasma immersion ion implantation and deposition (PIIID). Surface morphology and cross sectional morphology of the composite coating were characterized using atomic force microscopy and scanning electron microscopy, respectively. Although X-ray photoelectron spectroscopic analysis revealed that the Ti-O-N/Ti composite coating was composed of non-stoichiometric titanium oxide, titanium nitride and titanium oxynitride, no obvious characteristic peak corresponding to the crystalline phases of them was detected in the X-ray diffraction pattern. In accordance with Owens-Wendt equation, surface free energy of the uncoated and coated samples was calculated and compared. Moreover, the corrosion behavior of uncoated and coated samples was evaluated by means of electrochemical impedance spectroscopy measurement, and an equivalent circuit deriving from Randles model was used to fit Bode plots and describe the electrochemical processes occurring at the sample/electrolyte interface. On the basis of the equivalent circuit model, the resistance of the composite coating was 4.7 times higher than that of the passive layer on uncoated samples, indicating the enhanced corrosion resistance after PIIID treatment. Compared to uncoated Ti-6Al-V, Ti-O-N/Ti-coated samples facilitated ostoblast proliferation within 7 days of cell culture, while there was no statistically significant difference in alkaline phosphate activity between uncoated and coated samples during 21 days of cell culture.

Zinc ion implantation‑deposition technique improves the osteoblast biocompatibility of titanium surfaces.

The plasma immersion ion implantation and deposition (PIIID) technique was used to implant zinc (Zn) ions into smooth surfaces of pure titanium (Ti) disks for investigation of tooth implant surface modification. The aim of the present study was to evaluate the surface structure and chemical composition of a modified Ti surface following Zn ion implantation and deposition and to examine the effect of such modification on osteoblast biocompatibility. Using the PIIID technique, Zn ions were deposited onto the smooth surface of pure Ti disks. The physical structure and chemical composition of the modified surface layers were characterized by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS), respectively. In vitro culture assays using the MG-63 bone cell line were performed to determine the effects of Zn-modified Ti surfaces following PIIID on cellular function. Acridine orange staining was used to detect cell attachment to the surfaces and cell cycle analysis was performed using flow cytometry. SEM revealed a rough ‘honeycomb’ structure on the Zn-modified Ti surfaces following PIIID processing and XPS data indicated that Zn and oxygen concentrations in the modified Ti surfaces increased with PIIID processing time. SEM also revealed significantly greater MG-63 cell growth on Zn-modified Ti surfaces than on pure Ti surfaces (P<0.05). Flow cytometric analysis revealed increasing percentages of MG-63 cells in S phase with increasing Zn implantation and deposition, suggesting that MG-63 apoptosis was inhibited and MG-63 proliferation was promoted on Zn-PIIID-Ti surfaces. The present results suggest that modification with Zn-PIIID may be used to improve the osteoblast biocompatibility of Ti implant surfaces.

Multinuclear NMR and EPR Studies on Si-Doped Diamond-like Carbon

Recently, there is high interest in the development of diamond-like carbon (DLC) for a variety of applications in high strength, low-wear and low-friction film coatings. For instance, tool surfaces comprised of DLC are useful for machining electronic and optical components. Another example involved durable coatings for magnetic storage devices. Performance enhanced materials can be prepared by incorporating a few percent Si into the DLC. This has been done using plasma immersion ion-implantation and deposition (PIIID) by Professor Robert Carpick and his group at the University of Pennsylvania, who have provided materials for our investigation. During sample fabrication, the physical/chemical properties can be tailored, and correspondingly a large and variable combination of bulk and surface structures including dangling bonds will be present. In order to better understand these materials, we have carried out a study of the atomic level structure of Si-doped DLC using solid-state 1H, 13C and 29Si nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR). NMR is used to quantify the protons and investigate the carbon and silicon local structural environments, while EPR is employed to measure the unpaired electron spin concentration which is attributed to dangling bond defects. The ratio of carbon hybridizations (sp2:sp3) and the hydrogen content are two significant factors that gauge the mechanical properties of DLCs. We have found a sp2:sp3 ratio of 58:42, as measured by 13C MAS NMR for a Si-DLC sample, which contrasts with earlier studies of pure DLC materials.(1,2,3) Qualitatively, further evidence of the differences between sp2 and sp3 carbons is borne out through bonding scenarios with hydrogen, as this can be observed with the enhanced sp2 signal intensity via 13C-1H cross-polarization (CP). The normalized 1H NMR signal intensity gives an unexpectedly large hydrogen content as much as 5% by weight, though some of this is attributed to adsorbed water. In addition to these findings, 29Si-1H CP experiments provide direct evidence of silicon-hydrogen bonds. Unpaired electron spins in dangling bond defects are quantified from normalized EPR spectra. We measure roughly 2 × 1020unpaired electron spins/gram for Si-DLC. These preliminary measurements provide an interesting glimpse into the structure of PIIID prepared Si-doped DLCs. Many questions remain concerning the distributions of sp2 and sp3 carbons, Si-tetrahedra, etc., as well as how the structure can incorporate so many protons and defects. Similar NMR/EPR measurements for annealed samples (50o to 350oC) are in progress, as these are expected to provide valuable information concerning structural changes resulting from treatment at elevated temperature, which is important for device applications.Reference:(1) P.K. Chu, L.Li, Mater. Chem. Phys., 96(2006) 253-277(2) A.I.Shames, A.M.Panich,et al., J Phys. Chem. Solids, 63(2002) 1993-2001(3) N. Zumbulyadis, J.Chem.Phys., 86(1987) 1162-1166Acknowledgement:This work was supported by the National Science Foundation through a subcontract to Hunter College from the University of Pennsylvania.

Surface evolution of very high dose arsenic implants in silicon formed by plasma immersion ion implantation – a long term study

AbstractThe evolution of very high dose arsenic implants in silicon formed by plasma immersion ion implantation and deposition (PIIID) using a non‐pulsed plasma source was studied over a time period of more than one year. The study focused on the effect of arsenolite micro‐crystal formation, enhanced oxidation, and the significant As dose loss from as implanted samples at room temperature. The study was carried out combining analytical evidence from SIMS, XPS, INAA, SEM, and optical microscopy suggesting a two stage process of As dose loss, the first implying arsenolite crystal growth and the second an out‐diffusion. In fact, comparison of samples fabricated using different PIIID parameters showed that crystal growth seems not to be the only process responsible for dose loss. (© 2014 WILEY‐VCH Verlag GmbH &amp; Co. KGaA, Weinheim)

Sticky nano-thin films for the adhesion of polymers

Nanometre thick size films (about 2nm thick) that were plasma deposited using a mixture of polymerizing and non-polymerizing gases on a PEEK polymer surface resulted in a remarkable autohesive strength (up to 10 fold when compared with the untreated control). Experimental results on autohesion of semi-crystalline PEEK surfaces treated with plasma immersion ion implantation and deposition (PIIID) showed exceptionally strong autohesive bonds in lap-shear testing. Electron spin resonance (ESR) showed that the radical concentration increased linearly with plasma bias voltage. X-ray photoelectron spectroscopy (XPS) measurements showed no correlation between autohesive bonding strength and the concentration of oxygen and nitrogen elements and or the concentration of CO functional groups on the surface. Contact angle measurements showed that surface energy also showed no correlation. Bond strength values are linked with the percentage of the sp3 components of the C 1s region fitting in XPS spectra. There was strong relationship between the plasma treatment bias voltage and the plasma generated free radical density in the deposited thin film. Bond strength values are also correlated with the percentage of the sp3 components of the C 1s region fitting in XPS spectra. Free radicals induced covalent bonding might be suggested as the major contributor that leads to that the remarkable increase of the adhesion strength.

Surface modification of NiTi alloys using nitrogen doped diamond-like carbon coating fabricated by plasma immersion ion implantation and deposition

Nitrogen doped diamond-like carbon (N-DLC) coating was prepared on NiTi alloys using plasma immersion ion implantation and deposition (PIIID). The Raman spectrum confirms the coating processes the structure of diamond-like carbon. The XPS results reveal the nitrogen is doped into the diamond-like carbon, and CN bonds are formed in the coating. The scratch test displays that the DLC coating has good adhesion strength with the substrate. Anodic polarization has been carried out to examine the electrochemical corrosion behavior of the coated and uncoated samples. The result indicates that the corrosion resistance of the NiTi alloys is improved by the coating.

Effects of solid lubrication film on SKD11 in micro sheet forming

Liquid lubricant is widely used in macro sheet forming. However, it is not wise to use liquid lubricant for micro sheet forming because of friction size effects. Three kinds of solid lubrication films were proposed to treat SKD11 sample in this study. TiN and diamond-like carbon (DLC) films were fabricated by plasma immersion ion implantation and deposition (PIIID). However, MoS2 film was fabricated by magnetron sputtering. Raman spectrum, X-ray diffraction (XRD), atomic force microscope (AFM), ball-on-disc test and scratch test were used to investigate the structure, tribological property, and adhesion strength of the films. The results showed that comprehensive properties of the DLC film were much better than TiN and MoS2 films and can be chosen as a suitable lubricant for micro sheet forming. To further investigate the effect of DLC film to micro sheet forming, a micro deep drawing experiment was carried out by using a DLC film-coated micro blanking-deep drawing multiple operation mould. The results showed that the limiting drawing coefficient (LDC) and drawing force were dramatically decreased.

Optical, mechanical and surface properties of amorphous carbonaceous thin films obtained by plasma enhanced chemical vapor deposition and plasma immersion ion implantation and deposition

Diverse amorphous hydrogenated carbon-based films (a-C:H, a-C:H:F, a-C:H:N, a-C:H:Cl and a-C:H:Si:O) were obtained by radiofrequency plasma enhanced chemical vapor deposition (PECVD) and plasma immersion ion implantation and deposition (PIIID). The same precursors were used in the production of each pair of each type of film, such as a-C:H, using both PECVD and PIIID. Optical properties, namely the refractive index, n, absorption coefficient, α, and optical gap, ETauc, of these films were obtained via transmission spectra in the ultraviolet–visible near-infrared range (wavelengths from 300 to 3300nm). Film hardness, elastic modulus and stiffness were obtained as a function of depth using nano-indentation. Surface energy values were calculated from liquid drop contact angle data. Film roughness and morphology were assessed using atomic force microscopy (AFM). The PIIID films were usually thinner and possessed higher refractive indices than the PECVD films. Determined refractive indices are consistent with literature values for similar types of films. Values of ETauc were increased in the PIIID films compared to the PECVD films. An exception was the a-C:H:Si:O films, for which that obtained by PIIID was thicker and exhibited a decreased ETauc. The mechanical properties – hardness, elastic modulus and stiffness – of films produced by PECVD and PIIID generally present small differences. An interesting effect is the increase in the hardness of a-C:H:Cl films from 1.0 to 3.0GPa when ion implantation is employed. Surface energy correlates well with surface roughness. The implanted films are usually smoother than those obtained by PECVD.

Residual stress analysis of TiN film fabricated by plasma immersion ion implantation and deposition process

Titanium nitride (TiN) films were fabricated on AISI52100 bearing steel surface employing a hybrid plasma immersion ion implantation and deposition (PIIID) technique. The chemical composition, morphology and microstructure of TiN films were characterized by atomic force microscope (AFM), energy dispersive spectrometer (EDS), scanning electron microscope (SEM) and X-ray diffraction (XRD), respectively. The residual stress of TiN films under different deposition parameter conditions were measured by means of glazing incidence angle X-ray diffraction (GIXRD) method. The influence of film thickness and X-ray glazing incidence angle on residual stress were investigated. AFM observation reveals that the TiN films have extremely smooth surface, high uniformity and efficiency of space filling over large areas. XRD analysis results indicate that TiN phase exists in the surface modified layer and exhibits a preferred orientation with the (200) plane. The GIXRD data shows that the residual stress in as-deposited TiN films is compressive stress, and the residual stress value decreases with the film thickness and increases with the glazing incidence angle. The compressive stress reduces from 2.164GPa to 1.163GPa, which corresponds to the film thickness from 1.5μm to 4.5μm, respectively. Reasonably selecting PIIID process parameters for TiN films fabrication, the residual stress in the film can be controlled effectively.

Investigating the microstructure and mechanical behaviors of DLC films on AISI52100 bearing steel surface fabricated by plasma immersion ion implantation and deposition

The microstructure and mechanical properties of diamond-like carbon (DLC) films fabricated on an AISI52100 bearing steel substrate surface by plasma immersion ion implantation and deposition (PIIID) were studied. Atomic force microscope (AFM) observation reveals that the DLC film has an extremely smooth surface, and high uniformity and efficiency of space filling over large areas. Raman spectroscopy analysis indicates that DLC films are mainly constituted by amorphous and crystalline phases, with a variable ratio of sp2/sp3 carbon bonds, and sp3 bond content of more than 10%. The maximum nanohardness and elastic modulus of the DLC film are 40GPa and 430GPa, and increase by 263.6% and 95.5%, respectively. The friction and wear results exhibit that the friction coefficient against an AISI52100 steel ball decreases from 0.87 to 0.20. The corrosion polarization curves in a 3.5% saturated NaCl solution shows that the corrosion resistance of DLC/AISI52100 samples is much better than that of bearing steel substrate. Compared with the bare bearing steel, the surface mechanical property of the DLC/AISI52100 sample is improved significantly.

PIIID-formed (Ti, O)/Ti, (Ti, N)/Ti and (Ti, O, N)/Ti coatings on NiTi shape memory alloy for medical applications

(Ti, O)/Ti, (Ti, N)/Ti and (Ti, O, N)/Ti composite coatings were fabricated on NiTi shape memory alloy via plasma immersion ion implantation and deposition (PIIID). Surface morphology of samples was investigated using atomic force microscopy (AFM) and scanning electron microscopy (SEM). Cross-sectional morphology indicated that the PIIID-formed coatings were dense and uniform. X-ray diffraction (XRD) was used to characterize the phase composition of samples. X-ray photoelectron spectroscopy (XPS) results showed that the surface of coated NiTi SMA samples was Ni-free. Nanoindentation measurements and pin-on-disc tests were carried out to evaluate mechanical properties and wear resistance of coated NiTi SMA, respectively. For the in vitro biological assessment of the composite coatings in terms of cell morphology and cell viability, osteoblast-like SaOS-2 cells and breast cancer MCF-7 cells were cultured on NiTi SMA samples, respectively. SaOS-2 cells attached and spread better on coated NiTi SMA. Viability of MCF-7 cells showed that the PIIID-formed composite coatings were noncytotoxic and coated samples were more biocompatible than uncoated samples.

Diverse Amorphous Carbonaceous Thin Films Obtained by Plasma Enhanced Chemical Vapor Deposition and Plasma Immersion Ion Implantation and Deposition

Abstract Diverse amorphous hydrogenated carbon and similar films containing additional elements were produced by Plasma Enhanced Chemical Vapor Deposition (PECVD) and by Plasma Immersion Ion Implantation and Deposition (PIIID). Thus a-C:H, a-C:H:F, a-C:H:N, a-C:H:Cl and a-C:H:O:Si were obtained, starting from the same feed gases, using both techniques. The same deposition system supplied with radiofrequency (RF) power was used to produce all the films. A cylindrical stainless steel chamber equipped with circular electrodes mounted horizontally was employed. RF power was fed to the upper electrode; substrates were placed on the lower electrode. For PIIID negative high tension pulses were also applied to the lower electrode. Raman spectroscopy confirmed that all the films are amorphous. Chemical characterization of each pair of films was undertaken using Infrared Reflection Absorption Spectroscopy and X-ray Photoelectron Spectroscopy. The former revealed the presence of specific structures, such as C-H, C-O, O-H. The latter allowed calculation of the ratio of hetero-atoms to carbon atoms in the films, e.g. F:C, N:C, and Si:C. Only relatively small differences in elemental composition were detected between films produced by the two methods. The deposition rate in PIIID is generally reduced in relation to that of PECVD; for a–C:H:Cl films the reduction factor is almost four.