Summary



The Computing for Clean Water team has discovered how water can pass through tiny carbon nanotubes much more easily than previously predicted. This groundbreaking understanding of a fundamental physical process holds potential for improving access to clean water for millions through more efficient water filtration and desalination, as well as possible applications in clean energy and medicine. This discovery has been published in Nature Nanotechnology, the world's most prestigious nanotechnology journal.







Our team has discovered a phenomenon which forms an important step forward on the path to making clean water available to those who need it most. Clean water is fundamental to life, and yet nearly a billion people worldwide lack access to it. This isn't just a matter of convenience: over a million people die every year from diseases caused by unclean water. With population growth and climate change, the problem is expected to get worse. Existing water filter technologies are often expensive, and the people who need them most are least able to afford them. The Computing for Clean Water research that you powered can help change that status quo. These exciting findings were just published in Nature Nanotechnology, the world's most prestigious nanotechnology journal.



Fundamentally, our discovery is about how we can potentially use carbon nanotubes to make water filters that are more efficient and less expensive. Carbon nanotubes are made of single-atom-thick sheets of carbon atoms, called graphene, rolled up into tiny tubes, with diameters of just a few nanometers - one ten-thousandth the diameter of a human hair. The size of the tubes allows water molecules to pass through, but blocks larger pathogens and contaminants, purifying the water. They are so small that the scientific community initially expected that water would move through them too slowly to be useful. However, earlier experiments showed that water sometimes passes through them much more easily than expected.

Representation of volunteers contributing to the study of water within carbon nanotubes



Increased flow could mean a more efficient filter, but due to lack of sufficient computing power, until now there had been a wide gap between what scientists could understand from computer simulations, and what they could actually measure in experiments. Our research efforts focused on bridging this gap. By running massive computer simulations on World Community Grid with your help, we discovered that certain kinds of natural vibrations called phonons, under specific conditions, can lead to a 300%+ increased rate of diffusion (a kind of flow) of water through carbon nanotubes, compared to previous theoretical predictions. Importantly, since these tiny vibrations occur naturally due to thermal (heat) energy inherently stored in all materials, no external energy source is required to take advantage of this phenomenon.



What does this discovery mean for future research? The immediate application is in using the new insights from our simulations to design more efficient water filters. If experiments confirm our predictions, such filters could help improve access to clean water for millions of people worldwide. Our predictions may also lead to a less expensive method for desalinating water (the process of obtaining fresh water from sea water).



Utilizing this nanoscale phenomenon, it may be possible to construct membranes and filters that can revolutionize many processes and industries that involve water or other fluids. For instance, this discovery may reveal insights on how chemicals and medicines are transported through tiny channels in the walls of living cells. With further research, it might also be possible to apply these findings to improve a process that creates clean energy when freshwater and saltwater are mixed, a process known as osmotic power.



These diverse possibilities are only imaginable because of your generosity: no other research group had ever had the necessary computing power to run sufficiently detailed simulations to be able to compare directly with the flow conditions in real filters. By partnering with World Community Grid and the 150,000 volunteers who participated in this project, we were able to simulate water flow at a level of detail never attempted before, which revealed a phenomenon that had not been detected in previous studies.

Members of the Computing for Clean Water team: Zhiping Xu, Ming Ma Quanshui Zheng and Francois Grey



This work was a result of a global collaboration between researchers from China, Switzerland, Israel, the United Kingdom and Australia. Thanks to your participation, we were able to accomplish in just a few years what would have taken 40,000 years of computing on a single computer. On behalf of the entire team, I want to say thank you to the 150,000 World Community Grid volunteers who helped us run this research. This breakthrough belongs to you as well.





Learn more and join World Community Grid to power the next scientific breakthrough:



深入挖掘纳米技术潜力，改善数百万人难以获取清洁水的现状



清水计算团队发现了使水以更简单的方式流过微型碳纳米管的新方法。这一突破性发现可用于开发更高效的水过滤和淡化技术，从而改善数百万人难以获取清洁水的现状。该发现还可用于清洁能源和医疗行业。全球最知名的纳米技术期刊《自然纳米技术》已经发表了这一研究成果。



我们团队的这一发现将推动清洁水技术的发展，从而使有迫切需求的人们获得清洁水。清洁水是生命的基础，目前全球有近 10 亿人无法获得清洁水。这不仅仅是便捷性问题：每年逾百万人死于由于水质问题引发的疾病。随着人口增长和气候变化，这一问题将愈发严重。现有的水过滤技术通常价格高昂，需要清洁水的人们大都无法承受。您所支持的清水计算研究有助于改变这一现状。全球最知名的纳米技术期刊《自然纳米技术》已经发表了这些激动人心的研究成果。



我们从根本上发现了如何将碳纳米管用于制造更高效、更低成本的滤水器。碳纳米管采用单层原子厚度的碳原子板制成，这种材料被称为石墨烯，经弯曲后形成细管状，直径仅为几纳米，相当于人的头发直径的万分之一。碳纳米管的大小足以使水分子通过，但会挡住较大的病原菌和污染物，使水得到净化。碳纳米管的直径极小，以至于科学界最初认为水通过碳纳米管的速度极慢，因此不具有实用性。但早期的实验表明，水通过碳纳米管的速度有时会大大超过预期。



水的流速加快意味着更高效的过滤，但由于缺少足够的计算能力，科学家通过计算机模拟的数据与在实验中取得的实际测量结果存在巨大差异。我们的研究工作重点是努力缩小这一差异。通过全球网格大同盟的巨大计算模拟能力，我们发现了一种称为“声子”的自然振动。在特定的条件下，这种振动能够使通过碳纳米管的水分扩散（一种水流）速度提高 300% 以上。重要的是，这些振动源于所有物体本身具有的热能，无需外部能量就能够自然发生。



这一发现对于未来研究有何意义？从模拟中获得的新发现可以立即用于设计更高效的滤水器。如果实验能够验证我们的预测，这种过滤器将可以帮助改善全球数百万人难以获取清洁水的现状。我们的预测还可能会降低海水淡化技术的成本。海水淡化技术是一种从海水中获得淡水的工艺。



我们可以利用这一纳米层面的发现制造出滤膜与过滤器，为水或其它液体相关工艺和工业带来变革。比如，这一发现可以揭示化学品和药品如何穿过活细胞壁上的小通道。通过进一步研究，这些发现还可用于改进海水盐差能工艺，即通过混合淡水与海水来生产清洁能源。



没有您的慷慨参与，这些无数可能性都将无从谈起：没有研究团队拥有如此巨大的计算能力，以运行如此精密的模拟计算，从而直接比较过滤器中的实际水流状态。通过与全球网格大同盟以及参与本项目的 15 万名志愿者合作，我们才能进行前所未有的详细水流状态模拟研究，从而揭示在此前的研究中从未被发现的现象。



这一发现是我们与中国、瑞士、以色列、英国和澳大利亚研究人员共同努力的结果。由于您的参与，我们才能够在短短几年时间里完成了一台计算机需要 40,000 年才能够完成的研究。我仅代表整个团队，感谢帮助我们开展此项研究的 15 万名全球网格大同盟志愿者。这一突破性的研究成果同样也属于你们。