Everything You Need To Know To Find The Best titanium foam

SECTION 1. IDENTIFICATION

Product Name: Titanium Foam

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CAS #: -32-6

Relevant identified uses of the substance: Scientific research and development

Supplier details:

Stanford Advanced Materials

:

: (949) 407-

Address: Birtcher Dr., Lake Forest, CA U.S.A.

SECTION 2. HAZARDS IDENTIFICATION

Classification of the substance or mixture

Classification according to Regulation (EC) No /

The substance is not classified as hazardous to health or the environment according to the CLP

regulation.

Classification according to Directive 67/548/EEC or Directive /45/EC

N/A

Information concerning particular hazards for human and environment:

No data available

Hazards not otherwise classified

No data available

Label elements

Labelling according to Regulation (EC) No /

N/A

Hazard pictograms

N/A

Signal word

N/A

Hazard statements

N/A

WHMIS classificationNot controlled

Classification system

HMIS ratings (scale 0-4)

(Hazardous Materials Identification System)

HEALTH

FIRE

REACTIVITY

1

1

1

Health (acute effects) = 1

Flammability = 1

Physical Hazard = 1

Other hazards

Results of PBT and vPvB assessment

PBT:

N/A

vPvB:

N/A

SECTION 3. COMPOSITION/INFORMATION ON INGREDIENTS

Substances

CAS No. / Substance Name:

-32-6 Titanium

Identification number(s):

EC number:

231-142-3

SECTION 4. FIRST AID MEASURES

Description of first aid measures

If inhaled:

Supply patient with fresh air. If not breathing, provide artificial respiration. Keep patient warm.

Seek immediate medical advice.

In case of skin contact:

Immediately wash with soap and water; rinse thoroughly.

Seek immediate medical advice.

In case of eye contact:

Rinse opened eye for several minutes under running water. Consult a physician.

If swallowed:

Seek medical treatment.

Information for doctor

Most important symptoms and effects, both acute and delayed

No data available

Indication of any immediate medical attention and special treatment needed

No data available

SECTION 5. FIREFIGHTING MEASURES

Extinguishing media

Suitable extinguishing agents

Special powder for metal fires. Do not use water.

For safety reasons unsuitable extinguishing agents

Water

Special hazards arising from the substance or mixture

If this product is involved in a fire, the following can be released:

Metal oxide fume

Advice for firefighters

Protective equipment:

Wear self-contained respirator.

Wear fully protective impervious suit.

SECTION 6. ACCIDENTAL RELEASE MEASURES

Personal precautions, protective equipment and emergency procedures

Use personal protective equipment. Keep unprotected persons away.

Ensure adequate ventilation

Environmental precautions:

Do not allow material to be released to the environment without official permits.

Do not allow product to enter drains, sewage systems, or other water courses.

Do not allow material to penetrate the ground or soil.

Methods and materials for containment and cleanup:

Pick up mechanically.

Prevention of secondary hazards:

No special measures required.

Reference to other sections

See Section 7 for information on safe handling

See Section 8 for information on personal protection equipment.

See Section 13 for disposal information.

SECTION 7. HANDLING AND STORAGE

Handling

Precautions for safe handling

Keep container tightly sealed.

Store in cool, dry place in tightly closed containers.

Information about protection against explosions and fires:

No data available

Conditions for safe storage, including any incompatibilities

Requirements to be met by storerooms and receptacles:

No special requirements.

Information about storage in one common storage facility:

Store away from oxidizing agents.

Store away from halogens.

Store away from halocarbons.

Store away from mineral acids

Further information about storage conditions:

Keep container tightly sealed.

Store in cool, dry conditions in well-sealed containers.Specific end use(s)

No data available

SECTION 8. EXPOSURE CONTROLS/PERSONAL PROTECTION

Additional information about design of technical systems:

Properly operating chemical fume hood designed for hazardous chemicals and having an average

face velocity of at least 100 feet per minute.

Control parameters

Components with limit values that require monitoring at the workplace:

The product does not contain any relevant quantities of materials with critical values

that should be monitored at the workplace.

Additional information:

No data

Exposure controls

Personal protective equipment

Follow typical protective and hygienic practices for handling chemicals.

Keep away from foodstuffs, beverages and feed.

Remove all soiled and contaminated clothing immediately.

Wash hands before breaks and at the end of work.

Maintain an ergonomically appropriate working environment.

Breathing equipment:

Use suitable respirator when high concentrations are present.

Protection of hands:

Impervious gloves

Inspect gloves prior to use.

Suitability of gloves should be determined both by material and quality, the latter of which may vary by

manufacturer.

Penetration time of glove material (in minutes)

No data available

Eye protection:

Safety glasses

Body protection:

Protective work clothing

SECTION 9. PHYSICAL AND CHEMICAL PROPERTIES

Information on basic physical and chemical properties

Appearance:

Form: Solid in various forms

Color: Dark grey

Odor: Odorless

Odor threshold: No data available.

pH: N/A

Melting point/Melting range: °C ( °F)

Boiling point/Boiling range: °C ( °F)

Sublimation temperature / start: No data available

Flammability (solid, gas)

No data available.

Ignition temperature: No data available

Decomposition temperature: No data availableAutoignition: No data available.

Danger of explosion: No data available.

Explosion limits:

Lower: No data available

Ruiyun supply professional and honest service.

Upper: No data available

Vapor pressure: N/A

Density at 20 °C (68 °F): 4.506 g/cm

3

(37.603 lbs/gal)

Relative density

No data available.

Vapor density

N/A

Evaporation rate

N/A

Solubility in Water (H

2

O): Insoluble

Partition coefficient (n-octanol/water): No data available.

Viscosity:

Dynamic: N/A

Kinematic: N/A

Other information

No data available

SECTION 10. STABILITY AND REACTIVITY

Reactivity

No data available

Chemical stability

Stable under recommended storage conditions.

Thermal decomposition / conditions to be avoided:

Decomposition will not occur if used and stored according to specifications.

Possibility of hazardous reactions

No dangerous reactions known

Conditions to avoid

No data available

Incompatible materials:

Oxidizing agents

Halogens

Halocarbons

Mineral acids

Hazardous decomposition products:

Metal oxide fume

SECTION 11. TOXICOLOGICAL INFORMATION

Information on toxicological effects

Acute toxicity:

No effects known.

LD/LC50 values that are relevant for classification:

No data

Skin irritation or corrosion:

May cause irritation

Eye irritation or corrosion:May cause irritation

Sensitization:

No sensitizing effects known.

Germ cell mutagenicity:

No effects known.

Carcinogenicity:

No classification data on carcinogenic properties of this material is available from the EPA, IARC,

NTP, OSHA or ACGIH.

The Registry of Toxic Effects of Chemical Substances (RTECS) contains tumorigenic and/or

carcinogenic and/or neoplastic data for this substance.

Reproductive toxicity:

The Registry of Toxic Effects of Chemical Substances (RTECS) contains reproductive data for this

substance.

Specific target organ system toxicity - repeated exposure:

No effects known.

Specific target organ system toxicity - single exposure:

No effects known.

Aspiration hazard:

No effects known.

Subacute to chronic toxicity:

No effects known.

Additional toxicological information:

To the best of our knowledge the acute and chronic toxicity of this substance is not fully known.

SECTION 12. ECOLOGICAL INFORMATION

Toxicity

Aquatic toxicity:

No data available

Persistence and degradability

No data available

Bioaccumulative potential

No data available

Mobility in soil

No data available

Additional ecological information:

Do not allow material to be released to the environment without official permits.

Avoid transfer into the environment.

Results of PBT and vPvB assessment

PBT:

N/A

vPvB:

N/A

Other adverse effects

No data available

SECTION 13. DISPOSAL CONSIDERATIONS

Waste treatment methods

Recommendation

Consult official regulations to ensure proper disposal.Uncleaned packagings:

Recommendation:

Disposal must be made according to official regulations.

SECTION 14. TRANSPORT INFORMATION

UN-Number

DOT, ADN, IMDG, IATA

N/A

UN proper shipping name

DOT, ADN, IMDG, IATA

N/A

Transport hazard class(es)

DOT, ADR, ADN, IMDG, IATA

Class

N/A

Packing group

DOT, IMDG, IATA

N/A

Environmental hazards: N/A

Special precautions for user

N/A

Transport in bulk according to Annex II of MARPOL73/78 and the IBC Code

N/A

Transport/Additional information: DOT

Marine Pollutant (DOT): No

SECTION 15. REGULATORY INFORMATION

Safety, health and environmental regulations/legislation specific for the substance or mixture

National regulations

All components of this product are listed in the U.S. Environmental Protection Agency Toxic

Substances Control Act Chemical substance Inventory.

All components of this product are listed on the Canadian Domestic Substances List (DSL).

SARA Section 313 (specific toxic chemical listings)

Substance is not listed.

California Proposition 65

Prop 65 - Chemicals known to cause cancer

Substance is not listed.

Prop 65 - Developmental toxicity

Substance is not listed.

Prop 65 - Developmental toxicity, female

Substance is not listed.

Prop 65 - Developmental toxicity, male

Substance is not listed.

Information about limitation of use:

For use only by technically qualified individuals.

Other regulations, limitations and prohibitive regulations

Substance of Very High Concern (SVHC) according to the REACH Regulations (EC) No. /.

Substance is not listed.

The conditions of restrictions according to Article 67 and Annex XVII of the Regulation (EC) No/ (REACH) for the manufacturing, placing on the market and use must be observed.

Substance is not listed.

Annex XIV of the REACH Regulations (requiring Authorisation for use)

Substance is not listed.

REACH - Pre-registered substances

Substance is listed.

Chemical safety assessment:

A Chemical Safety Assessment has not been carried out.

SECTION 16. OTHER INFORMATION

Safety Data Sheet according to Regulation (EC) No. / (REACH). The above information is

believed to be correct but does not purport to be all inclusive and shall be used only as a guide. The

information in this document is based on the present state of our knowledge and is applicable to the

product with regard to appropriate safety precautions. It does not represent any guarantee of the

properties of the product.

Bone-related problems are commonly observed in clinic applications. Also, these problems economically and socially impose a significant burden. Thereby, due to the many reasons such as aging, the increasing of population and increasing in extreme sports among the young population, bone-related diseases are proposed to increase and become a public health problem1. Ti and its alloys, which possess wear resistance, great corrosion resistance and excellent biocompatibility, are the most widely preferred implant materials for dental and orthopaedic defects treatment2. However, there are unresolved technical problems on Ti-based implant such as bio-inert character, insufficient antibacterial capabilities and stress-shielding problem3,4. Compared to surrounding bone, Ti can lead to problems of stress-shielding due to its relatively high stiffness and this can subsequently result in loosening implant. To overcome stress-shielding problem, Ti foams are investigated for medical implant applications5,6,7. The porosity of Ti foams allows bone ingrowth and interlocking as well as more surfaces for bone-implant contact for medical implant applications7,8. The Young’ modulus of the implant, which is close to the human bone, is a vital in decreasing the mechanical mismatch between the implant and bone9,10. The low mechanical mismatch avoids stress shielding to the bone and increases the success ratio of the implant11. Furthermore, osseointegration is an important problem around Ti-based implant due to bioinert nature of Ti-based implant12. Ti cannot chemically bond to bone structure because it is a bioinert structure5. This leads to extend healing time. In order to overcome bioinert problem, oxide-based surfaces such as TiO2, hydroxyapatite etc. are fabricated on Ti-based implant by various surface modification techniques such as micro arc oxidation13, anodic oxidation14 etc.

TiO2 nanotubes are formed on the Ti sheets/plates by the AO technique15,16. The AO technique is a simple and common method to coat well-ordered TiO2 nanotubes on Ti substrates17. Within last years, TiO2 nanotubes arrays have taken huge attentions due to their efficiency in biomaterials since TiO2 nanotube surfaces are much more bioactive than Ti substrates18. Furthermore, it accelerates the rate of apatite formation and improves bone cell adhesion and proliferation19,20. However, very limited investigations were performed on the TiO2 nanotubes on Ti foam for implant and other applications in the literature. Huang et al. investigated electrochemical oxidation of carbamazepine in water using enhanced blue TiO2 nanotubes on porous Ti foam21. Bi et al. examined self-organized amorphous TiO2 nanotube on porous Ti foam for rechargeable lithium and sodium ion batteries22. Sang et al. evaluated multidimensional anodized titanium foam for solar cell applications23. Cao et al. investigated photodegradation properties of TiO2 nanotubes on Ti foam24. Haghjoo et al. examined the effect of TiO2 nanotubes on the biological properties such as cell response of porous Ti foam by AO for orthopaedic applications25. Izmir et al. evaluated bioactivity of TiO2 nanotubes on Ti6Al4V foams for orthopaedic applications26. However, the implant under body conditions is always associated with the risk of bacterial infection. This is caused by the adherence and colonization of bacteria on the surfaces of the implant27. The inhibition of bacterial adhesion, proliferation and provision of protection against infection is another goal for implant applications. In view of literature, there is no investigation on antibacterial efficiency of TiO2 nanotubes produced on pure Ti foam for medical applications in the literature.

Thus, the aim of this work is to investigate and improve antibacterial ability of TiO2 nanotube coated foams against potentially common bacteria (Staphylococcus aureus and Escherichia coli). In this work, TiO2 nanotube surfaces were produced on Ti foam by AO method. Phase structure, surface morphology and elemental structure of TiO2 nanotube surfaces on Ti foam were analysed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDX). Importantly, antibacterial efficiencies of TiO2 nanotube surfaces on Ti foam were investigated compared to E. coli and S. aureus for the first time in the literature.

In this study, in order to produce open foam structure, polyurethane foam (PU) was used as a template. A slurry is prepared using TiH2 powder (Alfa Aesar) and polyvinyl alcohol (PVA, Sigma Aldrich), Dolapix, ammonia and distilled water. Dolapix and ammonia were used as dispersants to control viscosity of the slurry and prevent sedimentation. First, distilled water was heated at 95 °C then 32% wt. PVA, 0.8% wt. Dolapix and 1.45% wt. ammonia were added and vigorously mixed by using a magnetic stirrer for 1 h. After the slurry reached homogeneous and transparent state, 60% wt. TiH2 powder was slowly added to the slurry under constant stirring. 20 mm × 20 mm × 20 mm size PU foams were immersed in the slurry. By pressing, excess slurry was removed to obtain open cell foam structure as described previous work6.

TiO2 nanotube coated at 40 V for 60 min in 0.5% wt. NH4F and 5.0% vol. distilled water containing ethylene glycol-based solution by a DC power supply (GW-Instek PSU 400). Ti foam and Pt plate were served as an anode and a cathode through AO process. The coated foams were cleaned in distilled water in an ultrasonic bath and they were warmly dried with a heat gun. Due to the amorphous structure of nanotube layers at post-production with AO process, the heat treatment was carried out in a muffle furnace at 450 °C for 60 min without changing the morphology as described previous work28,29. Then, they were cooled in the furnace. Schematic representation of fabrication TiO2 nanotube arrays on Ti foam by AO process were illustrated in Fig. 1.

The phase structures of the surfaces were analyzed by XRD (Rigaku Dmax ) with Cu-Kα radiation at a scanning speed of 1° min−1 from 20° to 80°. The surface morphologies of the samples were analyzed by SEM (Philips XL30S FEG). The elemental composition and amounts through the surface were investigated by EDX attached to SEM.

Adhesion of Staphylococcus aureus and Escherichia coli were evaluated by microbial adhesion experiments. All samples were first sterilized in an autoclave. The test microorganisms were set to a 0.5 McFarland scale and treated with the samples (1 cm2) immersed in 5 ml of MHB medium. The samples were then incubated at 37 °C and 125 rpm for 24 h on an orbital shaker. After the samples were removed from the medium, they were washed with 15 ml of water to remove non-adherent organisms, and this procedure was repeated three times. Then, each sample was placed in a clean tube, 2 ml of 150 mM NaCl was added, and shaken for 2 min to collect the bacteria adhering to the surface. Serial dilutions of the collected bacterial solution were prepared and 100 µL of the dilutions were spread on MHA medium. After 48 h of incubation at 37 °C, the number of colonies was measured and the percent inhibition was calculated. All experiments were performed in triplicate.

Surface topographies of Ti foam and nanotube coated foam surfaces were illustrated in Fig. 2. Titanium foams have an open-cell foam structure in which the gas phase dispersed in the matrix is continuous. As a result of the experiments, one-to-one replication of the PU foam was obtained. No significant difference was observed between the samples. However, during the coating of the model material with the mud mixture, it was observed that partially closed cells were formed in some parts of the model material as a result of clogging of the cell walls. The presence of closed cell walls is thought to be due to the high viscosity of the sludge mixture and the excess sludge impregnated with the PU foam cannot be removed by the pressure applied by compressing the foam. The surface of AO coatings consists of well-ordered nanotube arrays with approximately 75 nm through foam structure. The compact TiO2 film occurs at the early steps of AO process. Subsequently, this film gradually transforms into a porous layer. The pores randomly grow due to the effective etching of passive film by F- ions within ethylene glycol-based electrolyte. The AO process gradually leads to pores expansion due to long-term field-assisted chemical etching of the AO layer. Furthermore, initial pores develop during the pore rearrangement simultaneously30,31. Thus, well-ordered nanotube arrays form on Ti foams.

Elemental structures of Ti foam and nanotube coated foam surfaces were analyzed by EDX-area as shown in Fig. 3. Only, Ti and C elements were obtained on the surface of uncoated foam (Fig. 3a). The presence of C originates from decomposition of PU foam. The existence of Ti structure comes from foam structure as expected. In addition to Ti and C elements, nanotube coated surface contains both O and F elements as seen in Fig. 3b. The O and F elements exist in nanotube structures. The O and F elements originate in NH4F-based electrolyte. Furthermore, the O-based TiO2 phase was detected on TiO2 nanotube surfaces whereas as shown in Fig. 4. However, there is no the existence of the F-based crystalline phase. Thereby, it could be concluded that the F structure do not form crystalline phases on nanotube surfaces although it presences as the element in the nanotube structures.

Phase structures of bare Ti foam and nanotube arrays fabricated on Ti foams were indicated in Fig. 4. The phase of Ti (# 03-065-), TiC (# 00-001-) and TiO2 (# 00-021-) were observed on anodized Ti foam surfaces. It is clear that Ti and TiC come from Ti foam surface. It is reported that TiC is formed by the pyrolysis of binder phenolic resin. The removal temperature of PU foam and the decomposition temperature of the TiH2 are nearly identical. Thereby, the C may diffuse interstitial sites forming cubic TiC at post-leaving H2 in the system as asserted in the literature32. However, the nanotube arrays structure refers to the existence of TiO2 at post-heat treatment at 450 °C for 60 min as supported in Fig. 2b, c. The XRD peaks of the annealed nanotube surfaces at 2θ = 37.5°, 38.3° and 70.1° correspond to the (004), (112) and (116) crystallographic orientations of the TiO2 (# 00-021-). High temperatures such as 500–550 °C could increase the crystallinity of TiO2 nanotubes on Ti foam. However, as cited in experimental section, annealing process is applied to the nanotube surfaces on Ti plates 450 °C since morphological differences do not occur on the nanotube surfaces in the many literature studies14,20,25,28,29,33,34,35,36,37. If the annealing temperature was applied above 450 °C (500–550 °C), nanotube morphologies are importantly changed and damaged compared to pre-annealing.

Table 1 shows the numbers of E. coli and S. aureus attached to Ti foam and TiO2 nanotubes fabricated on Ti foam. Accordingly, TiO2 nanotubes doped surfaces decreased the adhesion of both bacteria to the surface compared to Ti foam surfaces. Studies have shown that TiO2 has antibacterial properties and has the ability to promote osteogenic differentiation38. When the modification of the implant surfaces with TiO2 nanostructures is carried out, it will be possible to make the implant more useful in terms of these properties. According to the results, TiO2 nanotube doped surfaces were found to be more effective on E. coli than S. aureus as seen in Fig. 5.

Many literature studies proposed the possible mechanisms between biological molecules and nanomaterials. It is believed in microbiology that microorganisms and metal oxides carry a negative charge and a positive charge, respectively. Therefore, electromagnetic attraction leads to create between treated surface and the microbe. Bacteria is oxidized at post-contacted the surface and dies instantly39. This causes cell inactivation at the signaling levels and regulatory network. Thereby, the respiratory chain’ activity is decreased40. All of these depending on the extensive cell wall and the membrane alterations can explain the biocidal activity of TiO2 structures such as nanotubes, nanoparticles, etc.

It is known that the antibacterial mechanisms of TiO2 including membrane stretching, charge repulsion and surface roughness variation are complex41. Charge repulsion between bacteria and TiO2 nanotubes prevents the initial adhesion. TiO2 possess photocatalytic nature. Thus, one of the main mechanisms of TiO2 nanotubes’ action is the generation of reactive oxygen species (ROS) on their surfaces through the photocatalysis process when they were exposed to light at an ideal wavelength42. This allows a greater ROS formation. This triggers damage on bacterial cell membrane/DNA etc. eventually, inhibiting the bacteria. Another important antibacterial mechanism of TiO2 is membrane stretching. Numerous bacteria such as E. coli and S. aureus have negative charges on their surfaces. Furthermore, the hydroxyl groups on TiO2 nanotube surfaces possess the negative charges. The existence of the same charges between TiO2 nanotubes and bacteria occur the repulsive forces reduce bacterial adhesion43. Bacteria keep their own shapes due to the difference in osmotic pressure between the inner and outer subshells44. Bacteria are initially stretched by the tensile force of the nanotubes and subsequently, it is torn. When the bacteria contacts to TiO2 nanotubes, the protruding tube walls increase the surface pressure of bacteria and a part of the membranes suspends over the hollow of the tubes. When the bacteria are consistently adsorbed onto the TiO2 nanotubes, the bacteria' surface area is expanded and the suspended membrane stretches further. Thereby, their cell membranes and tissues are damaged. Eventually, the death of the bacteria is accelerated45,46. Thus, TiO2 nanotube morphologies on Ti foam allowed a greater external and internal contact area with the bacterial solution.