钻石结构化晶体晶体由于其独特的特性而对许多应用具有吸引力。为了探索可用于胶体钻石结构自组装的设计师四面体斑块颗粒的制造,已发表在欧洲杯猜球平台PNAS。
学习:从四面体斑块颗粒中的胶体钻石轻松自组装通过环选择欧洲杯猜球平台。Image Credit: Potapov Alexander/Shutterstock.com
Fabrication of Diamond-Structured Colloidal Crystals
these crystal structures have been explored in recent years for their applications due to their photonic properties. Research has focused on strategies for the self-assembly of diamond-structured colloidal crystals due to their potential as a bottom-up, scalable process. Studies have shown some success in this field.
One of the forerunners in fabrication routes for the self-assembly of diamond crystals is using spherical particles which have a tetrahedral symmetry due to the presence of four patches. Whilst this method is hugely promising, achieving the self-assembly of diamond crystals from these patchy particles has thus far proven challenging for researchers.
自组装挑战
从本质上讲,从斑块颗粒创建自组装的钻石晶体结构的挑战本质上是动力学和热力学。欧洲杯猜球平台最近进行的许多研究都提出了这一点。
使用特定相互作用的四面体斑块颗粒系统中选择偶数环的设计策略。欧洲杯猜球平台(一种)四,五,六和七成员环的示例可以在四面体斑块颗粒的单组分系统中形成。欧洲杯猜球平台(b)示例可以在四面体斑块颗粒的两个组分系统中形成四个成员的环,其中只能在不同的物种之间形成键,标记为A(彩色黄色)和B(彩色粉红色)。欧洲杯猜球平台还显示了五成员环和七成员环的示例表明,奇数环无法在这种两组分组的四面体斑块颗粒系统中形成,因为它们需要A – A或B – B键。欧洲杯猜球平台(C – E)示例晶体结构可以通过四面体斑块颗粒的两个组分系统稳定:欧洲杯猜球平台(C)立方钻石,(d)hexagonal diamond, and((e)lathrate s-iii。薄的黑线代表晶体结构各个单位细胞的边缘。我们重点介绍了在椅子和船构中分别存在于立方和六角形钻石晶体中的代表六人环。此外,我们显示了具有虚线的围墙S-III结构中的基础网络,以强调表明单位电池中的四元和六成员环的布置,使它们形成截断的八面体。图片来源:Neophytou,A等人,PNAS
当斑块狭窄时,覆盖结构可以在动力学上比晶体结构相比,与结构中有六个成员相比,与五个成员形成环。相反,由于缺乏热力学力,很难从更宽的斑块中自发结晶。在这种情况下,必须对自发结晶进行超冷。
当斑块太宽时,结晶就会通过自然界无定形的玻璃网络的形成而预先避开,并且系统会经历动态停滞。在这个网络中,具有奇数甚至数字的环的分布不均匀,这不利于钻石结晶,这需要完全偶数的环。流体的本地秩序与水晶的全球秩序之间的挫败感发生了。
改善诱导钻石晶体自发自组装的过程
最近,两步合成过程已成为从斑块颗粒中产生自组装的钻石晶体的先驱。欧洲杯猜球平台两步过程抑制了五个和七成员的环的形成,仅留下有利于形成开放晶体的六个成员的环。因此,克服了导致动态停滞的局部流体顺序与全球晶体秩序之间的挫败感。
比较具有宽斑块的四面体斑块颗粒的单组和两组分组中的比较。欧洲杯猜球平台自组装((A – C)一个组件和((d-F)n = 1000个四面体斑块颗粒的两个组件系统带有斑块半角度欧洲杯猜球平台
在ρ*=Nσ3/V=0.5" id="MathJax-Element-20-Frame" role="presentation" tabindex="0">
ρ
ρ*=Nσ3/V=0.5" id="MathJax-Element-20-Frame" role="presentation" tabindex="0">*=nσ3/v=0.5。(一种和d)长度为l的平均环的演变(Rl" id="MathJax-Element-21-Frame" role="presentation" tabindex="0">
n
Rl" id="MathJax-Element-21-Frame" role="presentation" tabindex="0">rl)温度。(b和e)翻译顺序相关参数的概率分布函数d3在温度下
k
bt/ε=0.1 . (C and F) Representative snapshots of the configurations in the two systems at a temperature of
k
BT/ε= 0.1。图片来源:Neophytou,A等人,PNAS
to explore this hypothesis, the team behind the research published online in PNAS used a computational study. The two-step process was investigated in a system containing two designer tetrahedral patchy particles with identical patches in a 1:1 ratio mixture. Specific interactions were introduced by the computational study, meaning that bonds could only form between the two different particle types, which were labeled A and B. The bond-formation specificity was realized by DNA-mediated interactions.
粒子链只能形成闭合键环,其中链中的第一个和最后一个颗粒是不同物种的。欧洲杯猜球平台种间粘结限制了偶数纤维环的选择。两室系统可以形成六边形和立方晶体结构。此外,研究中强调的两步过程抑制了撞线的形成,但仍可以稳定S-III lates,由四个和六成员的环组成。
研究得出的结论是,计算研究中规定的设计规则不会与S-III杂质晶体竞争。这是由于四人和平面六人戒指之间的挫败感。由于系统的设计,可以去除过程中能量景观中的动力学陷阱。热力学驱动力增强了,这是设计的主要特征。
这项研究对该领域意味着什么
经过demonstrating a two-step process where interactions are only allowed between patches on different species, the research has presented a reliable method for spontaneous self-assembly of diamond-structured colloidal crystals from patchy particles. It was discovered that there was no competition from clathrate structures, which means that a purer sample of diamond crystals is produced without any dynamic arrest due to frustration between odd- and even-member rings.
钻石多型选择对四面体斑块颗粒的两组分系统中斑块宽度的依赖性。欧洲杯猜球平台(一种)斑块半角(θ)化学势差的依赖性(θ)Δμ" id="MathJax-Element-51-Frame" role="presentation" tabindex="0">
δ
Δμ" id="MathJax-Element-51-Frame" role="presentation" tabindex="0">μ)在温度下的两种组分系统的两种组分系统之间的立方钻石(CD)和六角钻(HD)之间欧洲杯猜球平台kBT/ε=0.1" id="MathJax-Element-52-Frame" role="presentation" tabindex="0">
k
kBT/ε=0.1" id="MathJax-Element-52-Frame" role="presentation" tabindex="0">bt/ε=0.1和压力P*=Pσ3/ε=0.0,0.1" id="MathJax-Element-53-Frame" role="presentation" tabindex="0">
p
P*=Pσ3/ε=0.0,0.1" id="MathJax-Element-53-Frame" role="presentation" tabindex="0">*=pσ3/ε= 0.0,0.1。误差线代表值中的SE,如通过块平均确定。(b)relative fractions of particles in a local cubic diamond (fcd" id="MathJax-Element-54-Frame" role="presentation" tabindex="0">
F
fcd" id="MathJax-Element-54-Frame" role="presentation" tabindex="0">光盘fcd" id="MathJax-Element-54-Frame" role="presentation" tabindex="0">
)和六边形钻石(fhd" id="MathJax-Element-55-Frame" role="presentation" tabindex="0">
F
fhd" id="MathJax-Element-55-Frame" role="presentation" tabindex="0">高清fhd" id="MathJax-Element-55-Frame" role="presentation" tabindex="0">
)在n = 4000个两部分四面体斑块颗粒的系统中自发晶体形成后的环境,其恒定密度的恒定密度欧洲杯猜球平台ρ*=Nσ3/V=0.3" id="MathJax-Element-56-Frame" role="presentation" tabindex="0">
ρ
ρ*=Nσ3/V=0.3" id="MathJax-Element-56-Frame" role="presentation" tabindex="0">*=nσ3/v=0.3和ρ*=0.5" id="MathJax-Element-57-Frame" role="presentation" tabindex="0">
ρ
ρ*=0.5" id="MathJax-Element-57-Frame" role="presentation" tabindex="0">*=0.5。每个数据点对应于25个独立模拟的平均值。请注意,在不同的温度下,对于不同的密度和斑块半角度观察到了自发成核。图片来源:Neophytou,A等人,PNAS
Understanding the mechanism of diamond crystal self-assembly promotion via ring size selection in relation to colloidal crystals will have implications for the future of the field, facilitating programmable crystal assembly. This will have further implications on processes to improve crystal formation in other materials such as tetrahedral network-forming liquids including silica and understanding the molecular mechanisms at play.
这项研究还将对利用钻石晶体结构成分的光子性质的设备的设计产生影响,最近的证据表明,立方结构具有更高的光子性能,并且随机堆叠的钻石晶体结构显示完整的光子带隙。
进一步阅读
Neophytou,A等。(2021)从四面体斑块颗粒中的胶体钻石轻松自组装通过环选择欧洲杯猜球平台[在线的]PNAS118:48 |pnas.org。可用网址:https://www.pnas.org/content/118/48/e2109776118
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