<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Suresh, Karthika</style></author><author><style face="normal" font="default" size="100%">Chowdhury, Arindam</style></author><author><style face="normal" font="default" size="100%">Kumar, Sanat K.</style></author><author><style face="normal" font="default" size="100%">Kumaraswamy, Guruswamy</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Critical role of processing on the mechanical properties of cross-linked highly loaded nanocomposites </style></title><secondary-title><style face="normal" font="default" size="100%">Macromolecules</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2019</style></year></dates><volume><style face="normal" font="default" size="100%">52</style></volume><pages><style face="normal" font="default" size="100%">5955-5962</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Polymer &lt;span class=&quot;hitHilite&quot;&gt;nanocomposites&lt;/span&gt; are frequently not at equilibrium-therefore, &lt;span class=&quot;hitHilite&quot;&gt;the&lt;/span&gt; structure and &lt;span class=&quot;hitHilite&quot;&gt;properties&lt;/span&gt; critically depend &lt;span class=&quot;hitHilite&quot;&gt;on&lt;/span&gt; &lt;span class=&quot;hitHilite&quot;&gt;the&lt;/span&gt; protocol followed in their preparation. Here, we demonstrate that &lt;span class=&quot;hitHilite&quot;&gt;the&lt;/span&gt; elastic-brittle transition in &lt;span class=&quot;hitHilite&quot;&gt;highly&lt;/span&gt; &lt;span class=&quot;hitHilite&quot;&gt;loaded&lt;/span&gt; ice-templated polymer &lt;span class=&quot;hitHilite&quot;&gt;nanocomposites&lt;/span&gt; is sensitively determined by &lt;span class=&quot;hitHilite&quot;&gt;the&lt;/span&gt; conformation &lt;span class=&quot;hitHilite&quot;&gt;of&lt;/span&gt; polymer chains during nanocomposite preparation. Macroporous polymer &lt;span class=&quot;hitHilite&quot;&gt;nanocomposites&lt;/span&gt; are synthesized using two preparation pathways, both exhibiting minor modifications &lt;span class=&quot;hitHilite&quot;&gt;of&lt;/span&gt; &lt;span class=&quot;hitHilite&quot;&gt;the&lt;/span&gt; ice-templating method wherein an aqueous dispersion &lt;span class=&quot;hitHilite&quot;&gt;of&lt;/span&gt; nanoparticles, polymers, and cross-linkers is frozen. In one method, &lt;span class=&quot;hitHilite&quot;&gt;the&lt;/span&gt; matrix polymer is &lt;span class=&quot;hitHilite&quot;&gt;cross-linked&lt;/span&gt; in &lt;span class=&quot;hitHilite&quot;&gt;the&lt;/span&gt; presence &lt;span class=&quot;hitHilite&quot;&gt;of&lt;/span&gt; ice, whereas in &lt;span class=&quot;hitHilite&quot;&gt;the&lt;/span&gt; other method, &lt;span class=&quot;hitHilite&quot;&gt;the&lt;/span&gt; ice is removed by freeze-drying before &lt;span class=&quot;hitHilite&quot;&gt;the&lt;/span&gt; polymer is &lt;span class=&quot;hitHilite&quot;&gt;cross-linked&lt;/span&gt;. Although all measurable structural metrics are practically identical for &lt;span class=&quot;hitHilite&quot;&gt;the&lt;/span&gt; two composites, they exhibit qualitatively different &lt;span class=&quot;hitHilite&quot;&gt;mechanical&lt;/span&gt; &lt;span class=&quot;hitHilite&quot;&gt;properties&lt;/span&gt;. &lt;span class=&quot;hitHilite&quot;&gt;Nanocomposites&lt;/span&gt; &lt;span class=&quot;hitHilite&quot;&gt;cross-linked&lt;/span&gt; in &lt;span class=&quot;hitHilite&quot;&gt;the&lt;/span&gt; presence &lt;span class=&quot;hitHilite&quot;&gt;of&lt;/span&gt; ice show exceptional resilience, recovering elastically from large compression for very high nanoparticle loadings-in some instances, above 90% by weight. Here, &lt;span class=&quot;hitHilite&quot;&gt;the&lt;/span&gt; &lt;span class=&quot;hitHilite&quot;&gt;critical&lt;/span&gt; particle loading for &lt;span class=&quot;hitHilite&quot;&gt;the&lt;/span&gt; elastic- brittle transition is dependent &lt;span class=&quot;hitHilite&quot;&gt;on&lt;/span&gt; &lt;span class=&quot;hitHilite&quot;&gt;the&lt;/span&gt; molecular weight &lt;span class=&quot;hitHilite&quot;&gt;of&lt;/span&gt; &lt;span class=&quot;hitHilite&quot;&gt;the&lt;/span&gt; polymer. In comparison, samples &lt;span class=&quot;hitHilite&quot;&gt;cross-linked&lt;/span&gt; after freeze-drying appear structurally identical but turn brittle at much lower particle loadings (about 60% by weight), independent &lt;span class=&quot;hitHilite&quot;&gt;of&lt;/span&gt; &lt;span class=&quot;hitHilite&quot;&gt;the&lt;/span&gt; matrix polymer molecular weight. We rationalize these differences in terms &lt;span class=&quot;hitHilite&quot;&gt;of&lt;/span&gt; &lt;span class=&quot;hitHilite&quot;&gt;the&lt;/span&gt; conformational state &lt;span class=&quot;hitHilite&quot;&gt;of&lt;/span&gt; &lt;span class=&quot;hitHilite&quot;&gt;the&lt;/span&gt; polymer during cross- linking. In &lt;span class=&quot;hitHilite&quot;&gt;the&lt;/span&gt; former case, polymer chains are in good solvent during nanocomposite preparation, while after lyophilization, they are in a poor solvent. &lt;span class=&quot;hitHilite&quot;&gt;The&lt;/span&gt; large spatial extent &lt;span class=&quot;hitHilite&quot;&gt;of&lt;/span&gt; well-solvated chains and chain-chain overlap during cross-linking results in &lt;span class=&quot;hitHilite&quot;&gt;the&lt;/span&gt; formation &lt;span class=&quot;hitHilite&quot;&gt;of&lt;/span&gt; intermolecular cross-links, and we obtain elastic &lt;span class=&quot;hitHilite&quot;&gt;nanocomposites&lt;/span&gt; even at high nanoparticle loadings. In contrast, for chains in collapsed conformations in a bad solvent, chain connectivity during cross-linking is achieved only for much lower particle loadings. Our results reiterate that &lt;span class=&quot;hitHilite&quot;&gt;the&lt;/span&gt; sensitivity &lt;span class=&quot;hitHilite&quot;&gt;of&lt;/span&gt; polymer conformations to different &lt;span class=&quot;hitHilite&quot;&gt;processing&lt;/span&gt; methods can result in large differences in &lt;span class=&quot;hitHilite&quot;&gt;properties&lt;/span&gt;, even though their consequences &lt;span class=&quot;hitHilite&quot;&gt;on&lt;/span&gt; structural characteristics are effectively indistinguishable.&lt;/p&gt;
</style></abstract><issue><style face="normal" font="default" size="100%">15</style></issue><work-type><style face="normal" font="default" size="100%">Article</style></work-type><custom3><style face="normal" font="default" size="100%">&lt;p&gt;Foreign&lt;/p&gt;
</style></custom3><custom4><style face="normal" font="default" size="100%">&lt;p&gt;&lt;span class=&quot;jhHeader_impact&quot;&gt;5.997&lt;/span&gt;&lt;/p&gt;
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