‘Smart’ microcapsules in a single step

ns480 — Fri, 10 Feb 2012 15:22:25 +0000

̽��ֱ��ability to enclose materials in capsules between 10 and 100 micrometres in diameter, while accurately controlling both the capsule structure and the core contents, is a key concern in biology, chemistry, nanotechnology and materials science.

Currently, producing microcapsules is labour-intensive and difficult to scale up without sacrificing functionality and efficiency. Microcapsules are often made using a mould covered with layers of polymers, similar to papier-mâché. ̽��ֱ��challenge with this method is dissolving the mould while keeping the polymers intact.

Now, a collaboration between the research groups of Professor Chris Abell and Dr Oren Scherman in the Department of Chemistry has developed a new technique for manufacturing ‘smart’ microcapsules in large quantities in a single step, using tiny droplets of water. Additionally, the release of the contents of the microcapsules can be highly controlled through the use of various stimuli.

̽��ֱ��microdroplets, dispersed in oil, are used as templates for building supramolecular assemblies, which form highly uniform microcapsules with porous shells.

̽��ֱ��technique uses copolymers, gold nanoparticles and small barrel-shaped molecules called cucurbiturils (CBs), to form the microcapsules. ̽��ֱ��CBs act as miniature ‘handcuffs’, bringing the materials together at the oil-water interface.

“This method provides several advantages over current methods as all of the components for the microcapsules are added at once and assemble instantaneously at room temperature,” said lead author Jing Zhang, a PhD student in Professor Abell’s research group. “A variety of ‘cargos’ can be efficiently loaded simultaneously during the formation of the microcapsules. ̽��ֱ��dynamic supramolecular interactions allow control over the porosity of the capsules and the timed release of their contents using stimuli such as light, pH and temperature.”

̽��ֱ��capsules can also be used as a substrate for surface-enhanced Raman spectroscopy (SERS), an ultra-sensitive, non-destructive spectroscopic technique that enables the characterisation and identification of molecules for a wide variety of applications, including environmental sensing, forensic analysis and medical diagnosis.

This research has been funded by the Engineering and Physical Sciences Research Council (EPSRC), the European Union and the European Research Council (ERC). ̽��ֱ��commercialisation of this research is supported by an ERC Proof of Concept grant, awarded to Dr Scherman.

A new, single-step method of fabricating microcapsules, which have potential commercial applications in industries including medicine, agriculture and diagnostics, has been developed by researchers at the ̽��ֱ�� of Cambridge. ̽��ֱ��findings are published Friday (10 February) in the journal Science.

This method provides several advantages over current methods as all of the components for the microcapsules are added at once and assemble instantaneously at room temperature.

Jing Zhang

̽��ֱ�� of Cambridge

Microcapsules

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Globalisation today: Chinese big business

bjb42 — Thu, 01 May 2008 15:40:30 +0000

China began liberalising the post-Mao economy in the late 1970s, when the world was embarking on a course of globalisation, forming close international trade and business links. Since the country began to integrate with the world’s economic and business systems, a consistently stated goal of China’s industrial policy has been to construct internationally competitive companies.

Dr Jin Zhang at Judge Business School has been closely studying the transformation of China’s strategic industries – aerospace, oil, telecommunications equipment and, most recently, banking – in the epoch of globalisation. Through extensive field work and in-depth case studies, her research explains China’s attempt in a rapidly changing international business environment to build its own internationally competitive firms, many of which are state owned and still central to China’s economic and political system.

Revolution versus evolution

In the past three decades, the world’s leading firms have undergone a revolutionary transformation, often described as the ‘global business revolution’. In order to survive and prosper, the nature of large firms based in high-income countries has had to alter greatly. Business and organisational structures have been fundamentally changed through mergers and acquisitions, facilitated by advances in information technology. In almost every sector, a small number of focused global producers have occupied the majority of the global market share, and this process has been cascading down their supply chain. ̽��ֱ��result is that leading firms in almost every industrial sector have become ‘conductors of an orchestra’, bringing together their supply chain to compete as a system in the world market.

By contrast, in the same period, China’s large firms have undergone more of an evolutionary process of restructuring, responding to the challenges of the global business revolution. They have made progress in improving operational mechanisms and corporate governance systems and have gained substantial understanding of international financial markets through public listing. They have become sought-after joint venture partners for global leading firms. However, they have also encountered a wide array of problems and difficulties associated with the transition of the vast economy.

With forces of globalisation and transition also at play, the attempt to construct competitive large firms in China has been all the more challenging. Indeed, when China joined the World Trade Organization (WTO) in 2001, China’s large firms in strategic industries lagged behind the world’s leading firms in each of the sectors.

̽��ֱ��future is dynamic

̽��ֱ��first phase of China’s attempt to develop large competitive firms in strategic industries was about introducing market forces. Now, China has entered the second phase of industrial restructuring. It is learning lessons from the global business revolution and is trying to construct effective industrial policy in the post-WTO era. Through a combination of state industrial policy and market mechanisms, China is consolidating firms in the strategic industries. Instead of breaking the country’s ‘big four’ state-owned banks into smaller entities, each of these four banks has restructured into share-holding companies and has successfully listed on international markets in the past five years.

China is also in the process of consolidating its aerospace industry, led by the project of producing a ‘big commercial jet’ in the next 20 years. These developments have been closely watched by leading global firms. ̽��ֱ��intertwining of changes in China’s internal business system with the revolution in large global firms has always been a protracted and complicated process. It is far from over. Interesting times lie ahead in the study of the development of China’s large firms in strategic industries as the country explores its way between state and market: the future is truly dynamic.

For more information, please contact the author Dr Jin Zhang (jz208@cam.ac.uk)at Judge Business School.

This year is the 30th anniversary of China’s policy of ‘reform and open up’. What has happened to China’s strategic industries and how competitive are Chinese big businesses today?

Since the country began to integrate with the world’s economic and business systems, a consistently stated goal of China’s industrial policy has been to construct internationally competitive companies.

Picfile on Flickr

Shanghai

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̽��ֱ�� of Cambridge - Jin Zhang

‘Smart’ microcapsules in a single step

Globalisation today: Chinese big business