多次書寫紙 打印不用墨

Experts have reveAled a new type of paper that can be erased and rewritten without the need for ink.
研究人員成功研製出一種可重複書寫的新型紙張，且書寫打印時無需油墨。

They say that even in early prototype form, it can be rewritten 20 times without affecting the resolution.
研究者稱，即使是初期版本，這種紙也能反覆擦寫20次，而且可保有較高的清晰度。

It works by using ultraviolet light to photobleach a dye in the paper, except the portions that constitute the text on the paper.
再寫紙的原理是：利用紫外光漂白某些染料，使之呈現出無色狀態，而只有文字或圖像可在紙上顯示出來。

The new rewritable paper can be erased and written on more than 20 times with no significant loss in contrast or resolution.
這種新的再寫紙能反覆擦寫20次多，且不會影響對比度或清晰度。

Chemists at the University of California,Riverside say their rewritable paper is based on the color switching property of commercial chemicals called redox dyes.
加利福利亞大學河濱分校（University of California, Riverside）的化學家們表示，再寫紙利用了氧化還原染料的顏色轉換特性。

The dye forms the imaging layer of the paper.
這種染料能形成紙的成像層。

'This rewritable paper does not require additional inks for printing, making it both economically and environmentally viable,' said Yadong Yin, a professor of chemistry, whose lab led the research, which is published today in Nature Communications.
殷亞東是加利福利亞大學的化學教授，他帶領團隊進行再寫紙的研究，其研究報告已發表於《自然通訊》（Nature Communications）雜誌。他說：“再寫紙在打印時無需添墨，使其在經濟和環保兩個方面都切實可行。”

'It represents an attractive alternative to regular paper in meeting the increasing global needs for sustainability and environmental conservation.'
“再寫紙可以作爲普通紙張之外另一種富有吸引力的選擇，它能夠滿足全球可持續發展和環境保護的需求。

Heating at 115 Cc an speed up the reaction so that the erasing process is often completed in less than 10 minutes.
這種紙加熱至115攝氏度時，其化學反應速率會加快，因此在不到10分鐘的時間內便可消除字跡。

'The printed letters remain legible with high resolution at ambient conditions for more than three days – long enough for practical applications such as reading newspapers,' Yin said.
殷教授表示：“印在紙上的文字可以在清晰度很高的情況下保持三天以上，對於讀報這樣的實際應用而言已經綽綽有餘。”

'Better still, our rewritable paper is simple to make, has low production cost, low toxicity and low energy consumption.'
“更妙的是，這種再寫紙製造簡單，且生產成本低、毒性低、能耗低。”

His lab is currently working on a paper version of the rewritable paper.
他的團隊目前正在改進紙質版的再寫紙。

'Even for this kind of paper, heating to115 Cposes no problem,' Yin said.
殷教授說：“這種紙加熱至115攝氏度也不會有問題。”

'In conventional laser printers, paper is already heated to200 Cin order to get toner particles to bond to the paper surface.'
“在使用傳統的激光打印機時，爲了讓調色劑粒子粘附到紙張表面，紙張需要加熱至200攝氏度。”

His lab also is working on increasing the cycling number (the number of times the rewritable paper can be printed and erased), with a target of 100, to reduce overall cost.
他的團隊也在致力研究如何增加再寫紙的循環數，即紙張重複打印和擦除的次數。他們希望再寫紙可重複使用100次，這樣便能降低生產總成本。

His research team is exploring ways to extend the legibility of the printed texts or images for more than three days to expand their potential uses.
同時，他們還想方設法提高三天後紙張上的文字和圖像的識別度，以擴大這種紙的潛在用途。

'One way is to develop new photocatalyst nanoparticles that become highly reductive when irradiated by ultraviolet light,' Yin said.
殷教授介紹：“其中一種方法是研製新的光催化劑納米顆粒，讓它在被紫外光照射時能高度還原。”

'We are exploring, too, the possibility of multi-color printing.
“同樣，我們也在探索多色印刷的可能性。

'The design principle can be extended to various commercial redox dyes to produce rewritable paper capable of showing prints of different colors.
“同樣的設計原理可擴展至其他各類氧化還原染料，然後有望製造出能夠彩印的紙張。

All these efforts will help increase the practical applications of the technology.'
這些付出都將有助於提高該技術的實際應用。”