Today's KNOWLEDGE SHARE: SEM(Scanning Electron Microscope)

Today's KNOWLEDGE SHARE:

SEM(Scanning Electron Microscope):

The electron source (often called the electron gun) provides a stable beam of electrons of adjustable energy, usually from between 20–30 eV to 30 keV. Three types of gun are available: thermionic, lanthanum hexaboride, and field emission.

A thermionic emission gun features a thin tungsten filament that is heated to a high temperature (about 2,800°K) to generate an electron beam. The tungsten filament is inserted head-down into a cone called the Wehnelt cup. The filament and Wehnelt cup form the negatively charged cathode, which effectively “forces” the electrons to flow towards an anode, which is a metal disk with a hole in the center. This focuses the beam, and the finest point of the beam is emitted (usually called the cross over) creating the emergent electron beam.

A lanthanum hexaboride (LaB6) gun uses a similar principle, but a lanthanum hexaboride crystal is used instead of the tungsten filament. Typically a LaB6 source achieves better resolutions and higher brightnesses compared to a tungsten source, but it is also a more expensive option, requiring a specialist technician to maintain the system and a superior vacuum to operate effectively.

A field emission gun heats a sharp metal tip, usually made of tungsten and with a radius of less than 100 nm, and uses two anodes to accelerate the resulting electron beam. Field emission guns achieve superior resolution, compared to thermionic emission and LaB6 guns, but they are also the most expensive type and require an ultra-high vacuum, which increases the O&M costs.

Lenses

In an SEM the lenses are magnetic. Each lens is made of current-carrying coils, where the current is adjusted to change the strength of the lens. There are two types of lens: condenser and objective. A condenser lens demagnifies the electron beam and is usually used in conjunction with apertures to collimate the beam. An objective lens focuses the beam on the sample, determining the final diameter of the electron probe. The objective lens is a key component of any SEM, affecting the final resolution and image quality.

SEM detectors

A field emission gun heats a sharp metal tip, usually made of tungsten and with a radius of less than 100 nm, and uses two anodes to accelerate the resulting electron beam. Field emission guns achieve superior resolution, compared to thermionic emission and LaB6 guns, but they are also the most expensive type and require an ultra-high vacuum, which increases the O&M costs.

When the electron beam reaches the sample surface, it “enters” the sample and interacts with it. The picture above shows the interaction volume, sometimes called interaction pear because of its distinctive shape.

The size and the shape of this interaction volume depend on the acceleration voltage and the density of the material. For example, if the voltage is high, the beam will penetrate more deeply into the sample. When it comes to the sample density, you have to understand how a beam will penetrate different material types where, for example, it is easier to penetrate a polymer material, compared to a stainless steel sample.

When the electrons enter the sample, one of three phenomena occurs. First, when the electrons hit the sample’s atoms, some are scattered off the sample’s surface. These are back-scattered electrons (BSE) and are high-energy electrons, which belong to the primary (incident electron) beam. They give compositional information about the sample and material contrast information. When interpreting BSEs, a higher grayscale level is usually synonymous with a higher atomic number. So, for example, gold will appear brighter than a polymer (which is mostly carbon and oxygen-based, representing low atomic number elements).

Second, secondary electrons (SE) are also used to generate the resultant image. Here, electrons from the primary beam hit the material’s atoms, and electrons from the material’s atoms are also kicked out of the sample’s surface. These are the secondary electrons, coming from the surface of the sample, and they provide information on the topography and morphology of the sample. The thickness of the region from where they are ejected is proportional to the accelerated voltage and density of the material.

The third, and final, type of signal commonly detected is characteristic X-rays. These are generated when a secondary electron is kicked out from a specific atom. This, in turn, generates a vacancy in a specific electron shell of that atom. Consequently, an electron from an outer shell (of the same atom) is forced to fill that vacancy, moving from an outer shell to an inner shell. This “movement” causes the ejection of a photon that has an energy that is characteristic of an element (hence, the name characteristic X-rays). These X-rays are detected by a specific detector called EDS (energy dispersive X-rays) that provides elemental information on the sample.

Source:Thermofisher

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#sem #image #resolution #materialsscience #electron #lenses #microscope

My speech at CINC 2023

 It was great to be part of the conference and all credits go to the CINC 2023 and CECA Team.

I would like to share with you all that I had given my speech on "Composites in the Hydrogen Economy" at the CINC 2023 Conference in Ahmedabad last week.

I spoke about the current scenario of the Hydrogen market and also shared some light on how BEV,FCEV,Green Hydrogen,LNG, Ammonia,Methanol,LH2 are going to change the environment in the coming years.

Hydrogen is not against any fuels that exist in the market at present but it is going to enhance the lifestyle of the millions.Nevertheless,the steps should be focussed on in the next 5 to 10 years to increase the momentum of the investment and subsidy parallelly to the projects in the hydrogen economy.

Also shared the significant growth on FCEV and the latest technological advancements in the manufacturing of Type4 CNG/H2 Cylinders in the global market.

I emphasized on the pricing strategy that is going to be on the milestone in the Hydrogen storage system within 3-7 years.Carbon fiber,thermoplastic and Thermoset resin systems that are all going to be produced via bio based feedstocks in a matured way in the future.

I specifically communicated the importance of Lightweight hydrogen tanks used in the automotive,maritime,Railways,aviation sectors and also shared my insights into the advantages of using Green hydrogen for steel,cement and other industries to witness better environments in the coming decade.

Looking forward to the next event in 2024.Let's learn together and share knowledge together!!!

Muthuramalingam Krishnan

University of Sydney develops recycling method to address carbon and glass fibre composites waste

Researchers at the University of Sydney have developed new methods to solve a major source of future waste from the automotive, aerospace and renewable industries.

It’s estimated that by 2030 carbon and glass fibre composites (CFRP), materials commonly used in wind turbine blades, hydrogen tanks, airplanes, yachts, construction, and car manufacturing, will be a key waste stream worldwide.

The annual accumulation of CFRP waste from aircraft and wind turbine industries alone is projected to reach 840,300 tonnes by 2050 – the equivalent of 34 full stadiums – if suitable recycling methods are not adopted. 

While recycling methods do exist, most of this waste currently goes to landfill or is incinerated. The production of “virgin” composites has further implications for the environment too, including resource depletion and high energy input during production. 

This is despite the existence of numerous methods to recycle carbon fibre composites which a research team at the University of Sydney says, if fully implemented, have the potential to significantly reduce energy use by 70 percent and prevent key streams of materials from going to waste. 

“Carbon fibre composites are considered a ‘wonder’ material – they are durable, resistant to weathering and highly versatile – so much so that their use is projected to increase by at least 60 percent in the next decade alone,” said Dr Hadigheh from the School of Civil Engineering. “But this huge growth also brings a huge increase in waste. For instance, it’s been estimated that around 500,000 tonnes of carbon and glass fibre composite waste from the renewable energy sector will exist by 2030.”

To tackle this issue, Dr Hadigheh and his recent PhD graduate Dr Yaning Wei have developed a new recycling method for carbon and glass fibre composites in a bid to prevent from end-of-generation materials going to landfill. Published in Composites Part B: Engineering their approach ensures increased material recovery and improved energy efficiency compared to previous methods.

“Our kinetic analysis revealed that pre-treated CFRP undergoes an additional reaction stage, enabling enhanced breakdown at lower temperatures compared to untreated CFRP,” said Dr Hadigheh. The solvolysis pre-treatment not only facilitates greater breakdown but also preserves the mechanical properties of fibres by reducing heat consumption during recycling.”

Recycled fibres obtained from pre-treated CFRP retained up to 90 percent of their original strength, surpassing the strength of fibres recovered through thermal degradation alone by 10 percent.

“To demonstrate the real-world applicability of our method, we successfully recycled part of a bicycle frame and airplane scraps made of CFRP composites using our hybrid approach. These results not only validate the effectiveness of chemical pre-treatment but also demonstrate the improved mechanical characteristics of the recycled carbon fibres,” said Dr Hadigheh.

Reclaiming carbon fibre:

In a previous paper, the team also presented a detailed evaluation of 10 different carbon and glass fibre composite waste treatment systems based on economic efficiency and environmental effects, taking into consideration the type of waste material and its geographical location. 

Dr Hadigheh’s team found that solvolysis – a method whereby materials can be broken down with an application of solvent under a specific pressure and temperature – could reclaim carbon fibre while delivering a high net profit. Thermal recycling methods such as catalytic pyrolysis and pyrolysis coupled with oxidation also provided a high economic return. 

Solvolysis and electrochemical methods were also shown to lead to substantially lower CO2 emissions into the atmosphere than landfilling and incineration. 

A huge opportunity:

The researchers said that manufacturers should look beyond continuously creating virgin material and, in parallel, develop recycled products from end-of-life streams.

“This is a huge opportunity,” said Dr Wei. “And not only because various modes of recycling are cost-effective and minimally impactful on the environment.”

“In an era of mounting supply chain disruptions, local recycled products can provide a more immediate product when compared to imports and create a burgeoning advanced manufacturing industry.

“While awareness of everyday consumer recycling is increasing and plastic waste is in the spotlight, Australia must urgently consider wide-scale recycling of new generation construction materials before they mount up as another waste problem and are put into the ‘too hard basket’.”

Dr Hadigheh’s team is also developing methods for the recycling of composite materials and recently patented a machine to precisely align recycled carbon fibres, so that they can be repurposed.

About the analysis:

The researchers conducted life cycle analysis (LCA), cost benefit analysis (CBA) and technology readiness level (TRL) assessments of the different waste treatment methods: landfill, incineration, mechanical recycling, catalytic pyrolysis, oxidation, pyrolysis combined with oxidation, fluidised bed, solvolysis using alkali and acid solvents, and electrochemical methods. 

Featured image: Dr Ali Hadigheh holding waste material from an aircraft. Image: Stefanie Zingsheim, University of Sydney.

Source:www.sydney.edu.au/ Jeccomposites

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Today's KNOWLEDGE Share: This carbon fiber Bugatti egg costs more the same as a supercar!

Today's KNOWLEDGE Share:

This carbon fiber Bugatti egg costs more the same as a supercar! 

This Fabergé-style Bugatti egg is made entirely out of carbon fiber and precious metals, and it costs the same as a Lamborghini! The egg was ‘hatched’ by Bugatti in partnership with Asprey, a UK-based jeweler, and the attention to detail makes it quite compelling. 

Known as the Royale Edition, the Bugatti egg is available in different colorways. The egg shell is made of carbon fiber and adorned with multiple sterling silver elephant motifs, as is the lattice around the egg shell. But the real cherry is found inside the egg, where you’ll find a miniature replica of the Molsheim factory where Bugatti was founded. 

Production of the Bugatti egg should remain limited to 111 pieces only, with incremental prices. The first hundred eggs should be priced between $20,000 and $50,000. Meanwhile, the other 11 eggs will be available with prices ranging between $150,000 and $200,000. One more thing, this being 2023, each physical egg will also come with its digital equivalent in the form of a Non-Fungible Token (NFT)! 

Source: SupercarBlondie #managingcomposites #thenativelab

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#composites #carbonfiber #bugatti

SEBS in medical Applications

 I have completed an assignment on Styrene Ethylene Butadiene Styrene block copolymer (SEBS)for medical applications for a well-reputed Asian company and shared my insights on Trends in healthcare,penetration into China and Indian market,acceptance level,capacity,demand,pricing strategy,Certification and Regulations,New entrant challenges in APAC,EU,MENA geographical regions and also share inputs on existing trends and comparison over other competitors in the global market.

I have covered an overview of the landscape of the market, key players of dominance in the Asia Pacific ,EU market and their market share in the various geographical regions.

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#SEBS #medical #healthcare #polymers #marketresearch #asiapacific #europe #marketshare #demandforecasting #trends #pricing #strategy #china #india

SABIC Launches PCR-Based PPE Resin Tech to Help Customers Reduce Carbon Footprint

SABIC announced its new PCR-based NORYL™ resin technology, formulated using 25 percent or more post-consumer recycled (PCR) content and aimed at providing additional, sustainable material options for customers.

The technology was validated through the commercialization of several grades, including NORYL™ NH5120RC3 resin containing 30 percent PCR content, which helps to lower its global warming potential (GWP) by 10 percent compared to the incumbent, fossil-based grade.

Offers Resin Customization to Meet Specific Application Requirements:

The latest PCR-based technology can be incorporated into more than 200 existing NORYL™ resin grades, as well as an unlimited number of new grades based on specific customer requirements. These include a glass fiber-reinforced grade and an unreinforced, non-FR grade.

Further, SABIC offers resin customization services to meet specific application requirements, as well as a full array of technical support services. It can help support circularity while maintaining the robust physical properties required for demanding applications. This innovative and sustainable solution is among the first polyphenylene ether (PPE)-based material technologies to incorporate such a significant level of recycled content.

Supports Sustainability with Non-brominated/Non-chlorinated FR:

"Developing PPE-based engineering resins with high percentages of recycled material is not trivial and poses a range of technical challenges,” said Luc Govaerts, technology director, Specialties, SABIC. "With our product and process expertise, our scientists developed a new PCR-based portfolio, and we are now launching our first flame-retardant NORYL™ material with consistent performance, including hydrolytic and dimensional stability and mechanical property retention in harsh outdoor environments.

New NORYL™ NH5120RC3 resin further supports sustainability with non-brominated/non-chlorinated flame retardance. The material, which may be well suited for electrical applications such as heating/ventilation/air conditioning (HVAC) enclosures and photovoltaic / solar junction boxes, has a UL94 flame rating of V1 at 1.5mm. It also delivers a good balance of flow, heat performance and creep resistance.

NORYL™ NH5120RC3 resin is globally available.

Bio-based Alternatives Coming Soon:

To further expand its sustainable materials, SABIC is introducing a bio-based PPE technology that can be used to formulate any NORYL™ resin grade. Based on ISCC PLUS certified feedstocks, this bio-based technology will offer customers the opportunity to specify up to nearly 100 percent renewable content in NORYL™, NORYL GTX™, NORYL PPX™ and Flex NORYL™ grades.

Source:Sabic/Specialchem

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#polymers #sustainability #noryl #polyphenyleneether #flameretardant #globalwarming #feedstocks #iscc #renewables #hvac