Hydrogels are novel materials with properties unlike those of normal polymers, but their potential applications have remained limited to small niches. A team of researchers from Japan aims to change that, and has discovered a new approach to hydrogels that yielded a trifecta of increased mechanical strength, easy preparation, and possible green-tech implications.
Hydrogels, as the name should imply, are mostly water (as much as 99 percent), and have a consistency that is best described as—you guessed it—a gel. This makes them a great candidate for novel biomedical applications like time-released targeted drug delivery and artificial tissues, because we’re mostly water, too. However, this makes them less useful for pretty much everything else outside of the body. They are often vulnerable to solvents and, as you might have noticed, there aren’t many items that actively rely on Jell-O as a structural component.
The researchers turned what might be a problem into a solution. The large, branchy dendritic polymer macromolecule they were working with had a tendency to adhere quite strongly to glass. So the researchers investigated its interactions with clay, which shares some properties with glass. Using an additional chemical that disperses clay nanosheets in water, they were able to get their dendritic macromolecule to form a structural framework with the the clay. The hydrophilic portion of the framework attracts and retains water molecules.
This notably improved mechanical properties over other hydrogels, as it could be molded into shapes that are free-standing and relatively robust and would undergo self-healing when cut. Less than 0.4 percent of it is petroleum-derived, so improved versions may provide an appealing green alternative to polymers. The best aspect, however, may be its simplicity: all you need are three ingredients, a beaker of water, and something to stir with.
Nature, 2010. DOI: 10.1038/nature08693
[source: http://arstechnica.com/science/news/2010/01/clay-based-hydrogels-could-be-green-alternative-to-polymers.ars]KUALA LUMPUR, Jan 21 — Two suraus in Muar, Johor were damaged in suspected arson attacks early this morning, weeks after similar attacks against churches, believed to be linked to the controversial “Allah” ruling.
Police found traces of kerosene in the Sirratulrahim Surau in Kampung Sabak Awor, Jalan Ismail which had a window and curtains burnt, while the Parit Beting surau suffered worse damage.
“There is a black mark on the door,” Muar Deputy OCPD Lee Choon Guan told The Malaysian Insider when contacted at the Parit Beting surau. Apart from the door, he said a carpet and windows were scorched. Stones were also reportedly thrown at the building.
The police forensics team is now taking evidence the surau.
PETALING JAYA: Various Malay-sian groups have started collecting funds to help earthquake victims in Haiti.
The Malaysia Red Crescent Society is appealing for donations for the MRCS International Relief Fund, in response to the emergency appeal launched by the International Federation of Red Cross and Red Crescent Societies (IFRC) for US$10mil (RM34mil) to assist some 100,000 disaster victims.
Cash or cheques can be sent to the MRCS headquarters at 32, Jalan Nipah, Off Jalan Ampang.
“Cheques should be made out to the ‘MRCS International Relief Fund’; with ‘Haiti Earthquake’ written at the back or banked in to MRCS Maybank account number 5144 2210 2657,” the statement said.
The Taiwan Buddhist Tzu-Chi Foundation Malaysia said it will hold a fund-raising drive today and tomorrow to collect money for relief work.
Those wishing to make donations can also contact 03-7880-9048 or visit www.tzuchi.my.
The Islamic Relief Malaysia (IRM), a humanitarian aid development agency with its head office in Birmingham, has also launched an appeal for contributions for the earthquake victims.
For more information, go to www.irm.org.my or call 03-8948-6334.
[source: http://thestar.com.my/news/story.asp?file=/2010/1/16/nation/5484892&sec=nation](马六甲)週四(1月14日)在武吉峇汝圣陶沙花园入口处遇车祸身亡的21岁女郎黄梅貽,一年前就曾告诉舅舅有意在去世后捐献器官的意愿,如今她不幸发生车祸去世,家人为完成她的心愿,今日(週五,1月15日)决定捐出眼角膜及长骨,遗爱人间。
死者一位不愿透露姓名的舅舅週五在中央医院告诉媒体,梅貽在吉隆坡读书时就住在他家里,约一年前,梅貽拿著捐献器官的表格回来,询问他的意见。
“当时我对她说,生命是无常的,只有死亡是肯定。捐献器官是好事,因为能够把希望带给更多的人,但是必须由自己决定。”
他指出,梅貽未来得及向父母表达她的意愿,就发生了车祸。家人获悉她生前的心愿后,决定遵循她的意愿,捐出梅貽的器官以拯救其他人。
KUALA LUMPUR – A MOSQUE was vandalised in Sarawak on Saturday, threatening to deepen the row between Muslims and Christians over the ‘Allah’ controversy.
Police found broken glass near the wall outside the mosque in Kota Samarahan, about 40km from the main town of Kuching. It was the first mosque attacked in the recent violence against places of worship.
‘Don’t make any speculation. We are investigating this incident,’ deputy police chief Ismail Omar told the media. ‘The situation remains peaceful and no one should take advantage of this to create something bad.’
The trouble was touched off by a High Court ruling last month that allowed a Catholic newspaper, the Herald, to use Allah to refer to God.
Since then, 10 churches and a Sikh Gurdwara temple have been vandalised.
The latest church was vandalised on Friday night in Seremban, Negeri Sembilan. Its side windows were broken.
Malaysian police yet to determine if attack in Sarawak is linked to Allah issue
By Elizabeth Looi, Malaysia Correspondent, 17 January 2010.
[source: http://www.straitstimes.com/BreakingNews/SEAsia/Story/STIStory_478464.html]