Increased Telomere Length and mtDNA Copy Number Induced by Multi-Walled Carbon Nanotube Exposure in the Workplace

Carbon nanotubes (CNTs) except MWCNT-7 have been classified as Group 3 ["Not classifiable as to its carcinogenicity to humans"] by the IARC. Despite considerable mechanistic evidence in vitro/in vivo, the classification highlights a general lack of data, especially among humans. In our previous study, we reported epigenetic changes in the MWCNT...

Cryogenic properties of cnt reinforced uhmwpe laminated composites

Energy transition towards cleaner fuels and renewable energy brings the attention to liquefied natural gas (LNG) and liquid hydrogen (LH2) applications. Cryogenic storage temperatures make the suitable material selection for the construction of such applications difficult. Ultra-high molecular weight polyethylene (UHMWPE) thermoplastics are...

Cardiovascular effects among workers exposed to multiwalled carbon nanotubes

Objectives: The increase in production of multiwalled carbon nanotubes (MWCNTs) has led to growing concerns about health risks. In this study, we assessed the association between occupational exposure to MWCNTs and cardiovascular biomarkers. Methods: A cross-sectional study was performed among 22 workers of a company commercially producing...

Human health risks of exposure to carbon nanotubes: keeping pace with innnovation

The worldwide production of carbon nanotubes (CNTs) has increased substantially in the last decade as the material offer society new opportunities for effectively stronger, lighter, better electrically conductive, and more flexible products. However, concerns have been raised about (occupational) health risks due to CNT exposure, but...

A cross-sectional study of changes in markers of immunological effects and lung health due to exposure to multi-walled carbon nanotubes

Background: Multi-wall carbon nanotubes (MWCNTs) are manufactured nanomaterials to which workers and the general population will be increasingly exposed in coming years. Little is known about potential human health effects of exposure to MWCNTs, but effects on the lung and the immune system have been reported in animal and mechanistic studies....

A new approach combining analytical methods for workplace exposure assessment of inhalable multi-walled carbon nanotubes

To date there is no consensus about the most appropriate analytical method for measuring carbon nanotubes (CNTs), hampering the assessment and limiting the comparison of data. The goal of this study is to develop an approach for the assessment of the level and nature of inhalable multi-wall CNTs (MWCNTs) in an actual workplace setting by...

Changes in DNA methylation induced by multi-walled carbon nanotube exposure in the workplace

This study was designed to assess the epigenetic alterations in blood cells, induced by occupational exposure to multi-wall carbon nanotubes (MWCNT). The study population comprised of MWCNT-exposed workers (n=24) and unexposed controls (n=43) from the same workplace. We measured global DNA methylation/hydroxymethylation levels on the 5th...

Highly stable carbon nanotube top-gate transistors with tunable threshold voltage

Carbon-nanotube top-gate transistors with fluorinated dielectrics are presented. With PTrFE as the dielectric, the devices have absent or small hysteresis at different sweep rates and excellent bias-stress stability under ambient conditions. Ambipolar single-walled carbon nanotube (SWNT) transistors are observed when P(VDF-TrFE-CTFE) is utilized...

Miniaturized reaction chamber for optimized laser-assisted carbon nanotube growth

The localized growth of carbon nanotube structures has potential in many applications such as interconnects, field emitters and sensors. Using a laser to locally heat the substrate offers a highly versatile process compatible with a broad range of substrates and devices. However, for laser-assisted CNT growth, detailed process information, such...

Laser-assisted growth of carbon nanotubes on laser-patterned substrates and inside sealed micro-channels

Carbon nanotube assemblies can be used for specific applications such as sensors and filters. We present a method and proof-of-concept to directly grow vertically-aligned carbon nanotube structures within sealed enclosures by means of a feedback-controlled laser-assisted chemical vapor deposition technique. The process is compatible with a...

Examples and Case Studies

Release of nanomaterials may occur during any stage of the life-cycle and can eventually lead to exposure to humans, the environment or products. Due to the large number of combinations of release processes and nanomaterials, release scenarios can currently only be tested on a case-by-case basis. This chapter presents five case studies on...

Laser-assisted growth of carbon nanotubes - A review

Laser-assisted chemical vapor deposition (LACVD) is an attractive maskless process for growing locally carbon nanotubes at selected places on substrates that may contain temperature-sensitive components. This review gives a comprehensive overview of the reported research with respect to laser assisted CVD for the growth of carbon nanotubes. The...

Kinetics of laser-assisted carbon nanotube growth

Laser-assisted chemical vapour deposition (CVD) growth is an attractive mask-less process for growing locally aligned carbon nanotubes (CNTs) in selected places on temperature sensitive substrates. The nature of the localized process results in fast carbon nanotube growth with high experimental throughput. Here, we report on the detailed...

Potential release scenarios for carbon nanotubes used in composites

The expected widespread use of carbon nanotube (CNT)-composites in consumer products calls for an assessment of the possible release and exposure to workers, consumers and the environment. Release of CNTs may occur at all steps in the life cycle of products, but to date only limited information is available about release of CNTs from actual...

In-situ localized carbon nanotube growth inside partially sealed enclosures

Carbon nanotube assemblies can be used for specific applications such as sensors and filters. We present a method and proof-of-concept to directly grow vertically-aligned carbon nanotube structures within sealed enclosures by means of a feedback-controlled laser-assisted chemical vapor deposition technique. The process is compatible with a...

Isotactic polypropylene/carbon nanotube composites prepared by latex technology: Electrical conductivity study

Several series of nanocomposites were prepared using a latex-based process, the main step of which consisted of mixing an aqueous suspension of exfoliated carbon nanotubes (CNTs) and a polymer latex. In the present work, a systematic study on the electrical properties of fully amorphous (polystyrene - PS) as well as semi-crystalline (isotactic...

Application and characterization of nanomaterials in energetic compostions

As part of a cooperation between several TNO institutes, including TNO Prins Maurits Laboratory, recently a new initiative on nanotechnology was started. The research subjects within this initiative can be roughly divided into two areas: (1) Instrumentation for analysis and manufacture at nano-scale and (2) Nanoscale engineering techniques to...