吶喊為挪威畫家愛德華·孟克的作品,其呼喊的「怪異」樣貌形象非常鮮明。928Please respect copyright.PENANAsYc1KbxyZc928Please respect copyright.PENANA5igD57bPuy
928Please respect copyright.PENANAdmAtleQ4Tk
他本人在1893至1916年畫出多個版本,而其中一幅展示在孟克美術館(Munch Museum)的版本因多處黃色地方出現變白及脫落跡象關係(圖1的數字標記區域),自2006年起已甚少公開示人。928Please respect copyright.PENANA6Dl3aoRXuY
928Please respect copyright.PENANAk6dRuG712Q
作品現時正處於光線陰淡、攝氏18度、相對濕度約50%的環境備受保護。928Please respect copyright.PENANAFAGS2pJyt7
928Please respect copyright.PENANAWuZfPoCvOg
928Please respect copyright.PENANAajTdkOXO5c
(圖2)為了解箇中顏料變色及脫落的機制,有科學家對吶喊作品作出深入研究,並在近日發表文章講述得出的結果(Ref1)。928Please respect copyright.PENANA47C9wiy8cG928Please respect copyright.PENANAqW6xrEAOU5
928Please respect copyright.PENANA1dsxew1QBG
Cadmium sulfide,為該時期常用作為黃色顏料的化學物。928Please respect copyright.PENANAbPK4wyTfwW
928Please respect copyright.PENANAm4c1VczTIW
同期的文森·梵谷 (Vincent van Gogh)、詹姆斯・恩索 (James Ensor)和亨利·馬諦斯(Henri Matisse)均有利用這種化學物所製成的顏料,而相關的作品亦有出現黃色顏料變白的現象。928Please respect copyright.PENANAOXHbRBqZQk
928Please respect copyright.PENANAoEvnebQnMz
該時期主要有兩種方式製作Cadmium sulfide,分別為Dry及Wet Method。928Please respect copyright.PENANAwtrr6tpyXr
928Please respect copyright.PENANA4FFLl1NvlF
Dry Method為以300°C至600°C及零氧氣的方式,加上大量硫元素(Sulphur)調配Cadmium sulfide的方式,得出的成品相對上較為純正。928Please respect copyright.PENANAPVmyBdOc9Y
928Please respect copyright.PENANAA9dYjzQtZ0
Wet Method為將不同的化學物混合在一起(如圖中所示),再以沉澱的方式獲取固體Cadmium sulfide。928Please respect copyright.PENANAdkkwFehgXv
基於當時技術相對上不太先進,最終的產品會含有較多雜質及副產品。928Please respect copyright.PENANAOHudnMNHmw
928Please respect copyright.PENANA3urySdyeq2
(圖3)科學家在文中嘗試挖取微量的吶喊畫碎粒,再利用各種技術檢測畫中的化學物成份。928Please respect copyright.PENANArAYdixMdD8928Please respect copyright.PENANA2k2C0aQbKF
928Please respect copyright.PENANAfOB4HloUQL
圖3中間的圖片,其紅點代表黃色顏料Cadmium sulfide的存在。928Please respect copyright.PENANAOEDULXqW7N
928Please respect copyright.PENANAAxy9JCoOvS
下方的圖片,其三種顏色的出現分別代表Wet Method的副產物。928Please respect copyright.PENANA5knXDdWz1j
928Please respect copyright.PENANAhWGQsY7idh
紅點:Cd(OH)Cl928Please respect copyright.PENANA4yAxfaQWll
綠點:CdSO4928Please respect copyright.PENANA7vDyqtbrmo
藍點:CdCO3928Please respect copyright.PENANA7wh93LMQfo
928Please respect copyright.PENANAY9dGfkdXvn
這三種副產物,在長久而來的知識中已被確認是顏料變色及脫落的兇手,與吶喊作品所出現的現象不謀而合。928Please respect copyright.PENANAA0PsPmIPWK
928Please respect copyright.PENANAaS60BQu310
(圖4)為進一步了解顏料變色的現象,他們找來了吶喊畫同期帶有黃色顏料的作品(他們已7914數字命名樣本)。928Please respect copyright.PENANAH0btWkxH0u928Please respect copyright.PENANAdyt0EqWiBT
928Please respect copyright.PENANAGPbNxvWaUC
拿取畫中碎片後,(圖4左方)他們同樣發現裡頭含有Wet Method的副產物(綠點)。928Please respect copyright.PENANAVW2fJ1q3Rk
928Please respect copyright.PENANAFercqOY00P
為了解環境因素對於顏料變色的影響,他們對另一塊畫碎用上90 日相對濕度≥ 95%,攝氏為40°C,無光環境來模仿歲月的摧殘。928Please respect copyright.PENANA5UnptVMQdI
928Please respect copyright.PENANAUpju7vdSvb
他們發現得到Wet Method的副產物Cd(OH)Cl(綠點)數量大增且集中在一起,其目測得到黃色顏料變白的現象發生。928Please respect copyright.PENANA8r5T6Oof4R
928Please respect copyright.PENANArT5goxNTlK
然而,用上用上90 日相對濕度=45%,攝氏為30°C,300W光源直接照射的環境來模仿歲月摧殘的話,則沒有感測得到Wet Method副產物的產生和顏料變色現象發生。928Please respect copyright.PENANAiikT9IUIRq
928Please respect copyright.PENANAHemgTtKqc8
928Please respect copyright.PENANANypoM3CTqk
(圖5)另外,他們亦對愛德華·孟克那時期捐贈予館舍的顏料油作出檢測。928Please respect copyright.PENANA9e4CWqDACw928Please respect copyright.PENANASJbzjqZ4C6
928Please respect copyright.PENANA52MAhSCzvX
在畫紙塗上顏料油後,已能測量得到有一定程度份量的Wet Method副產物Cd(OH)Cl(左圖綠點)。928Please respect copyright.PENANAU4irs5pHyS
928Please respect copyright.PENANAFTm3j2QaXx
(右圖)用上90 日相對濕度≥ 95%,攝氏為40°C的方式摧殘後,綠點數量大增且集中在一起。928Please respect copyright.PENANANhyCnQsbNv
928Please respect copyright.PENANAOi1JYsFs22
928Please respect copyright.PENANANwx9fOlyW0
(圖6)換句話說,當時期以Wet Method製作的Cadmium sulfide顏料以及愛德華·孟克所使用的顏料油,乃是導致畫中黃色地方出現變白及有脫落跡象的元兇,而其變色的機制主要由相對濕度和溫度而非光線控制。928Please respect copyright.PENANAd8SrIICHLJ928Please respect copyright.PENANAjbc3oMjs4F
928Please respect copyright.PENANAa9TNsxkPbH
基於這發現,在相對濕度及溫度嚴密的控制下,吶喊他日將來也許會有機會可以再度長期公開示人。928Please respect copyright.PENANAwheeKn0Y03
928Please respect copyright.PENANA3p9p4hH6zp
如果想我快啲出文的話,請入去Penana網站科普專欄–薯不揀單俾一個like以及Bookmark,這對我非常之重要。928Please respect copyright.PENANAw2xGaHNj6J
928Please respect copyright.PENANAlgBnnsEZFz
Link: https://www.penana.com/story/66244/%E7%A7%91%E6%99%AE%E5%B0%88%E6%AC%84-%E8%96%AF%E4%B8%8D%E6%8F%80%E5%96%AE/toc928Please respect copyright.PENANAzZClpP1lfw
928Please respect copyright.PENANAA40aZkF4eN
同時亦可以在Penana網站裡按「買一嚿/半嚿薯仔」,以課金的方式推動我繼續搜羅資料寫文,多謝。928Please respect copyright.PENANAKCOHQ1Zvls
928Please respect copyright.PENANAr3vpr5yewc
Link:928Please respect copyright.PENANA1E54bfwoRF
https://www.penana.com/user/27349/%E8%96%AF%E4%BB%94%E8%81%9E%E8%8C%B1%E8%8E%89/portfolio928Please respect copyright.PENANAghz4QIBvug
928Please respect copyright.PENANAPUKBukZbyW
928Please respect copyright.PENANA9b9pA84sDo
有興趣接收科學資訊的話,歡迎follow IG: potatopigtongue。928Please respect copyright.PENANAdEl652euxT
928Please respect copyright.PENANAbfGjyWM3fX
Ref1:https://advances.sciencemag.org/content/6/20/eaay3514928Please respect copyright.PENANAhL3W8srCYK