Evidence map›Paper›PMID 26788966›Full record

ArticleACS nano2016

The Importance of Excess Poly(N-isopropylacrylamide) for the Aggregation of Poly(N-isopropylacrylamide)-Coated Gold Nanoparticles.

Samuel T Jones, Zarah Walsh-Korb, Steven J Barrow, Sarah L Henderson, Jesús del Barrio, Oren A Scherman

Abstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in ACS nano, 2016. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 30 papers.

0numbers the graph read from it
0cells of the map it votes in
30citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

30 citing papers in PubMed.

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  20. Cascaded nanooptics to probe microsecond atomic-scale phenomena.Proceedings of the National Academy of Sciences of the United States of America · 2020
    Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

6 authors.

Samuel T JonesMelville Laboratory for Polymer Synthesis, Department of Chemistry, Cambridge University , Lensfield Road, Cambridge CB2 1EW, U.K.
Zarah Walsh-KorbMelville Laboratory for Polymer Synthesis, Department of Chemistry, Cambridge University , Lensfield Road, Cambridge CB2 1EW, U.K.
Steven J BarrowMelville Laboratory for Polymer Synthesis, Department of Chemistry, Cambridge University , Lensfield Road, Cambridge CB2 1EW, U.K.
Sarah L HendersonMelville Laboratory for Polymer Synthesis, Department of Chemistry, Cambridge University , Lensfield Road, Cambridge CB2 1EW, U.K.
Jesús del BarrioMelville Laboratory for Polymer Synthesis, Department of Chemistry, Cambridge University , Lensfield Road, Cambridge CB2 1EW, U.K.
Oren A SchermanMelville Laboratory for Polymer Synthesis, Department of Chemistry, Cambridge University , Lensfield Road, Cambridge CB2 1EW, U.K.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Thermoresponsive materials are generating significant interest on account of the sharp and tunable temperature deswelling transition of the polymer chain. Such materials have shown promise in drug delivery devices, sensing systems, and self-assembly. Incorporation of nanoparticles (NPs), typically through covalent attachment of the polymer chains to the NP surface, can add additional functionality and tunability to such hybrid materials. The versatility of these thermoresponsive polymer/nanoparticle materials has been shown previously; however, significant and important differences exist in the published literature between virtually identical materials. Here we use poly(N-isopropylacrylamide) (PNIPAm)-AuNPs as a model system to understand the aggregation behavior of thermoresponsive polymer-coated nanoparticles in pure water, made by either grafting-to or grafting-from methods. We show that, contrary to popular belief, the aggregation of PNIPAm-coated AuNPs, and likely other such materials, relies on the size and concentration of unbound "free" PNIPAm in solution. It is this unbound polymer that also leads to an increase in solution turbidity, a characteristic that is typically used to prove nanoparticle aggregation. The size of PNIPAm used to coat the AuNPs, as well as the concentration of the resultant polymer-AuNP composites, is shown to have little effect on aggregation. Without free PNIPAm, contraction of the polymer corona in response to increasing temperature is observed, instead of nanoparticle aggregation, and is accompanied by no change in solution turbidity or color. We develop an alternative method for removing all traces of excess free polymer and develop an approach for analyzing the aggregation behavior of such materials, which truly allows for heat-triggered aggregation to be studied.

Indexed as

aggregateaggregationgoldLCSTnanoparticleNIPAmN-isopropylacrylamide

Identifiers

PMID26788966
PMCPMC4838950

What OpenQuestion holds

Textmetadata
Read underepoch 390

Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.