Connect with us

Chemicals

One-dimensional confinement
Molecular-weight polymer selection

Published

on


Chemicals

Researchers at Kanazawa University report in Nature Communications that a crystal of molecules known as pillar[5]arenes can form a host–guest compound with poly(ethylene oxides) polymers. The effect can be used to select polymers with different molecular weights and end groups.

When polymers are confined into one-dimensional (1D) channels, they behave differently. Their dynamics changes, and they may chemically bind to the surrounding channel. A team of researchers led by Tomoki Ogoshi from Kanazawa University has now shown that such 1D confinement, provided by a molecular crystal of so-called activated pillar[5]arenes, can be used to selectively capture different types of polymers.

The scientists studied host–guest binding (‘complexation’) between activated pillar[5]arenes (abbreviated ‘P5’) and poly(ethylene oxide) polymers (abbreviated ‘PEO’). P5 is a molecule consisting of 5 identical organic units featuring a benzene ring, with a pentagonal shape. The monomeric building block of PEO is O-CH2-CH2; PEOs with 100 or more monomers can easily be synthesized.

Host–guest complexation was achieved by first melting PEO at 80°C, and then immersing the P5 molecules activated by drying solvates into the melt. By means of nuclear magnetic resonance (NMR) spectroscopy measurements, Ogoshi and colleagues were able to show that PEO molecules were taken up by the P5 structure. X-ray diffraction experiments showed that the crystal structure of the P5 molecules had changed into a network featuring channels.

The researchers then looked at what happened with a mixture of PEOs consisting of various numbers of monomers. The number of building blocks affects the weight — the more monomers, the heavier the polymer. Ogoshi and colleagues discovered that the heavier PEOs were taken up in larger quantities, showing that the P5 host can select PEOs with high mass fraction from a polydisperse mixture. By means of computer simulations, it was possible to attribute this finding to an increased binding energy for the larger (heavier) PEOs.

The scientists also investigated the effect of the PEO’s end group. The fastest PEO uptake was observed for methoxy end groups (O-CH3), for which an equilibrium state was reached after 3 minutes. For OH and NH2 end groups, the times to reach equilibrium were 10 and 20 minutes, respectively. Uptake for PEO with COOH as the end group was slow.

The observation by Ogoshi and colleagues that P5 crystals can perform high mass fractionation from polymer mixtures with a broad molecular-weight distribution is important because, quoting the scientists, “high-molecular-weight polymers generally exhibit superior characteristics such as increased thermal stability, improved mechanical properties, and higher crystallinity compared with low-molecular-weight polymers.”

Chemicals Food & Beverage Pharmaceuticals Safety & Security

RFID access control in hazardous areas
Fast and secure access to processes

Published

on

Integrated RFID readers for fast and secure access control at HMI systems also in hazardous areas. Picture: R. Stahl
Integrated RFID readers for fast and secure access control at HMI systems also in hazardous areas. (Picture: R. Stahl)

Security and access control are given top priority in the production process, as unauthorised users and operating errors can cause great damage. R. Stahl is the only manufacturer in the market offering its explosion-protected Thin Clients with RFID authentication for secure identification of staff with access authority for process control and data communication from the field. On the basis of three technology platforms, the Thin Clients have been designed to meet the different requirements of the chemical and pharmaceutical industries, the food industry as well as oil and gas production.

Additional logins in the automation system are no longer required due to the faster, direct RFID access control, which meets the current security requirements according to FDA and Gamp. It supports transponders with Mifare, Desfire, EV1 or Legic Advant reader technologies. Unlike biometric processes, the contactless RFID technology is also suitable for hygienically sensitive areas where obligatory protective clothing makes authorisation via fingerprint or face recognition impossible. R. Stahl’s explosion-protected RFID readers have been certified for Zones 1/21 and 2/22. They are either available as separate units with a USB interface for panel mounting, or they are integrated directly into the operator enclosures or keyboards by the manufacturer.

The Thin Clients designed for the oil and gas industry with the Shark technology device platform and 21.5″ touchscreens are also available with a RFID reader installed behind the front plate. User authorisation via RFID requires the installation of a suitable device driver in the control system software. On request, the company will provide cards and key fobs equipped with tested transponders for use in hazardous areas.

Continue Reading

Chemicals Measurement, Instrumentation, Control & Automation News Pharmaceuticals Plant Construction, Engineering & Components Water & Waste Water

Dialogue between manufacturers and users
Satisfied customers through integration

Published

on

Dialogue between manufacturers and users. At the Open Integration meeting in Reinach, Switzerland, in early June, representatives from the chemical and pharmaceutical industries explained how they benefit from the partner program during digitalization of their process control systems. Picture: Endress + Hauser
Dialogue between manufacturers and users. At the Open Integration meeting in Reinach, Switzerland, in early June, representatives from the chemical and pharmaceutical industries explained how they benefit from the partner program during digitalization of their process control systems. (Picture: Endress + Hauser)

35 Open Integration partners gathered together at Endress + Hauser in Reinach, Switzerland, to share their experiences and thoughts for the first time. A highlight of the event was a presentation from representatives of the chemical and pharmaceutical industries outlining how they benefit from the partner program during digitalization of their processes – and what they would like to see in the future.

The goal of the Open Integration program initiated by Endress + Hauser can be summed up quickly: the simple, fast and manufacturer-independent integration of components and devices into various automation systems. And, almost more importantly, satisfied customers.

While it sounds simple in theory, when it comes to day-to-day system operation, it’s far from that. Even the most experienced automation specialists have great respect for multi-vendor systems. That also applies to complete solutions “from a single source.” After all, digital communications – a precondition for the extensive use of existing intelligence in field devices and systems – places serious demands on integration.

With its Open Integration partner program, Endress + Hauser is inviting providers of control technology, fieldbus infrastructure, measurement technology and actuator systems to test and document the interaction of their products even more extensively in the interests of their customers. The cooperation partners include Auma Riester, Bürkert, Festo, Flowserve, Hima Paul Hildebrandt, Honeywell Process Solutions, Mitsubishi Electric, Pepperl + Fuchs, Phoenix Contact, Rockwell Automation, Schneider Electric and Turck.

Open standards as a basis

The foundation of this effort is open communication standards (Hart, Profibus, Foundation Fieldbus, EtherNet/IP or Profinet), as well as open integration standards (FDT, EDD, FDI). With a nearly unlimited selection of options, the reference topologies represent practical combinations suitable for applications in the chemical, life sciences, food & beverage, oil & gas, power & energy, primaries & metal and water & wastewater industries.

The reference topologies take into account industry-typical requirements such as explosion protection, availability and redundancy. Each topology is thoroughly tested and documented in the lab in Reinach in conjunction with the partners, after which the recommendations are published.

Interoperability tests create added value

And how do customers benefit from the Open Integration partner program? Every problem that the integration experts discover prior to commissioning can be resolved at a much lower cost compared to fixing the issue in the field at some later point. Customers receive concrete, validated recommendations for automating their systems, which go well beyond established conformity and interoperability testing while ensuring seamless integration. Last but not least, they save time and money.

With developments such as IIoT and APL, users will face new challenges, plus integration testing will be given added weight. This makes it even more important for the Open Integration partners to work together over the long term. The participating customer and provider representatives were in full agreement on this point. Cyber security, in addition to the issue of connectivity, will play a key role in the future. They furthermore agreed that effective strategies need to be developed to counter new entrants in the automation industry such as IBM or Amazon.

Customer-driven developments

One thing was clear during the get-together in Reinach in early June: the process control industry wants open, interoperable systems instead of proprietary solutions. One of the users wants uniform, structured access to static information via QR- and RFID-supported type plates in accordance with DIN 91406. Standardized diagnostics in line with NE 107 is also at the top of the wish list.

In the near term, Endress + Hauser wants to work with its partners to address these and other open issues with the aim of utilizing Open Integration to offer customers even more value-add during digitalization of their processes. The common goal: satisfied customers who can extensively utilize the opportunities that digitalization brings with little risk.

Continue Reading

Chemicals Mechanical & Thermal Processes Plant Construction, Engineering & Components

Metal bellows
The ideal connection

Published

on

Jakob Antriebstechnik
Picture: Jakob Antriebstechnik

In the manufacture of metal bellows couplings, bellows and hub connections are a critical issue. While steel or stainless steel couplings can be combined with a special micro plasma welding process, this method is not suitable for combinations of aluminum and steel. Adhesive bonding processes can be used here, but they can fail under extreme operating conditions (chemicals, very high or low temperatures). Especially in the case of clutches on the input side of a planetary gear, high temperatures can occur in critical applications which could loosen the adhesive bonds.

The developed and long-time patented joining process (crimping-in-press process), on the other hand, is optimally suited for connecting multi-layer stainless steel bellows without clearance to aluminum hubs. Here the operation is certainly possible even in temperature ranges from -50 ° C to + 350 ° C.

Continue Reading