Composite Silica:Polypeptide Colloidal Particles Paul S. Russo Macromolecular Studies Group Louisiana State University Materials Science & Engineering Department North Carolina State University Friday, November 9

Generic Outline Slide

Thank hosts for inviting me Tell jokes Why is the research interesting?

(if not interesting, at least important) Background material Plan of attack (hypothesis/testing) Results Discussion/Conclusion Questions 4/27/2020 Self-recrimination

French Air Force Vive l’audacite!

4/27/2020

Canada’s Armed Forces Have Been Deployed

4/27/2020

Minnesota National Guard

4/27/2020

Fuzzballs

a silica interior and synthetic homopolypeptide exterior. Silica (SiO 2 ) core typically 200 nm diameter Homopolypeptide Shell typically 100 nm thick

Why?

The usual reasons for polymer-coated particles  Stability studies, probe diffusion, standards, etc.

  The

better

reasons for

polypeptide-

coated particles 

Should

allow excellent shell thickness control.

Shell is rigid spacer for assembling silica spheres.

Astounding chemical versatility and functionality, including chirality.  Responsiveness and perfection of structures through reproducible helix-coil transitions.

Making the Particles

  Picture is for a shell of PBLG = poly(benzyl glutamate) [NH-CHR’-CO] x with R’=(CH 2 ) 2 COOBz Other shells so far PCBL= poly(carbobenzoxy-L lysine) R’=(CH 2 ) 4 NHCOOBz HO HO OH (H 3 CO) 3 Si NH 2 H 2 N O Si O OH Si O O O NH 2 O Si O Si O NH NH 2 2 RO O O H N O O R = Benzyl NH NH NH NH

Is the shell covalently attached?

s our ce : stob ers IR 16 14 12 10 8 6 4 2 0 -2 4000 (a) 3500 s tober 1628 802 946 3000 2500 2000 Wavenumber / cm -1 1500 1000 500 Figure 2a Fong and Russo so urce: bf2cp 33 IR s ou rc e: b f5 ttIR p1 48 14 12 (b) 10 (c) 10 8 6 1736 1551 1653 4 PBLG-coated silica 2 4000 3500 3000 2500 2000 Wavenumber / cm -1 1500 1000 8 500 Figure 2b Fong and Russo 6 1391 4 1654 2 DMF Washed 0 4000 3500 3000 2500 2000 Wavenumber / cm -1 1500 1000 500 Figure 2c Fong and Russo

Almost certainly

(By the way, the polypeptide conformation is mostly a -helix with some b -sheet)

TGA/DTA

0 -20 -40 -60 -80 -100 0 Silica Spheres Alone Mixed with 16K and 91K PBLG, then isolated (2 curves) Composite Particle 200 PBLG 400 600 T / o C 800 1000 1200 Fong and Russo Figure 3 --Particles with ~ 23% by mass PBLG --Again, no evidence for binding of loose PBLG

Dynamic Light Scattering

5.0

4.5

4.0

3.5

3.0

2.5

2.0

1.5

1.0

1.0

1.5

R h = 990 Silica Spheres C 18 H 37 Spheres Composite Particles R h = 973 2.0

2.5

q 2 /10 10 cm -2 3.0

R h = 1750 3.5

4.0

Bigger ones may diffuse slower (solvent viscosity effects) Flat plots indicate excellent, latex-like uniformity

 

Particle Characteristics

Silica Core Properties   Radius from DLS: 97 nm Molar Mass: 4.5 x 10 9 Surface area: 15.6 m 2 /g  PBLG Shell Properties    78 nm.

~90% solvent / 10% polymer.

Polymer density limited by crowding around initiator sites.

Shell thickness not controlled by [M]/[I] --Not all initiators are active: crowding.

--Controlling and assaying initiator density are ongoing challenges.

--Attachment of ready-made polymers to surfaces increasingly appealing.

      

Conclusions

Facile synthesis of composite silica/homopolypeptide core/shell organophilic particles.

Excellent uniformity.

Shell highly solvated. Nonionic colloidal crystals that may prove amenable to control via conformational transitions.

Potential applications include optical devices, stationary phases for chiral separation and model particles for studies of polymer/colloid interactions.

Polypeptide chemistry allows almost infinite variation.

Much development remains to be done. In particular, thickness is not yet easily controllable.

Colloidal Crystals (PCBL Shell)

Why Study?

 Beautiful!

 Fun supramolecular synthesize & ~ 2 mm characterize from

nm

to

mm.

~ 0.5  m SiO 2 visible light, diffraction results. separations technology Domains with different orientations result in different and quite pure colors.

Helical homopolypeptide shell

Transmittance measured on monochromator equipped microscope 3.5

3.0

2.5

2.0

1.5

1.0

0.5

0.0

400 Transmitted Light Intensity vs. Wavelength PCBL/Silica Composite Particle Imaged region includes 3 domains 568 nm 500 593 nm 615 nm 600  /nm 700 FWHM of line is ~ 16 nm, comparable to typical interference filters of conventional design

Achieving population inversion gets progressively harder for shorter wavelengths;  green <  red .

E 2 A 12 B 12

B

12

A

12   3 8  E 1  

Modulation FPR Device

PA OS PMT * DM OBJ S * RR D TA/PVD * * L AOM 4/27/2020 M M

4/27/2020

4/27/2020 0.5

10 -7 10 -6 Before Sonication 0.0

-0.5

-1.0

10 -7 10 -6 10 -5 10 -5 R h /cm 10 -4 10 -4 10 10 -3 After Sonication -3 10 -2 4.0

3.5

3.0

2.5

2.0

1.5

1.0

0.5

10 -2 0.0

N N N N N N N Silica coating Surface Functionalization N N N N N N N NCA-monomer N N N N N N N crosslinking N N N N N N N 4/27/2020

Fuzzballs: nm to mm

Helical polypeptides SiO 2 4/27/2020 Colloidal crystal •diffract visible light •ours will be smart !

Colloidal chain •chiral stationary phase?

•can they swim?

•Can they be hollow?

 vis

What label should we put on this science and those who do it?

  Reviewer of a recent paper said it was

synthetic

. If so, then it’s

MacroSynthetic

--our monomer has

M ~

10 9 g/mol.     Characterization requires some physical concepts.

It borrows heavily from biology: a -helical design and transitions to other conformations. Applications are materials-oriented.

So….the person who does this is a jack of all trades, master of some. He or she is employable!

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Thanks for your hospitality

“The work of the righteous is done by others.” --God Sibel Turksen – still with me Brian Fong – Buckey Technologies, Memphis Wieslaw Stryjewski – Resident Equipment Guru National Science Foundation American Chemical Society 4/27/2020

Observe! Wonder! Have Fun!

Current Grad Students

•Garrett Doucet •Randy Cush •Sibel Turksen •Rongjuan Cong

Collaborators

•George Newkome •Greg Baker •Chuck Moorefield •Duen-wu Hua 4/27/2020

Current Undergrads

•Jonathan Strange •Martinique Perkins •Rae-lynne Poirrier

Current Postdocs

•???

•???

•???

Ph.D. Alumni

NAME YEAR PAPERS PUBLISHED 4 Mark DeLong 1989 WORKS AT Union Carbide Mazidah Mustafa Zimei Bu 1990 1994 Debbie Tipton 1995 Daewon Sohn 1995 Keunok Yu 1995 Lucille Smith Wright 1999 3 6 3 6 3 2+ Housewife Yale & NIST Chevron Han-Yang University Kunsan Universisty USGS WHERE S. Charleston WV Detroit, MI NH & DC Orange, TX Seoul, Korea Kunsan, Korea Baton Rouge 4/27/2020

Collaborations

 At LSU      Hammer/McCarley/McLaughlin Daly/Negulescu Bricker Strongin Soper Thomas   Visitors from other places (not including industry!)        METU--Ankara, Turkey (Kucukyavuz) Indiana-Purdue University (Dubin) Georgia Tech (Srinivasarao) U. South Florida (Newkome) Minnesota (Bloomfield) NIST (Amis) Han-yang--Korea (Sohn) 4/27/2020

Reversibly

Freezing in LC transitions

Melt —note colors & lines Frozen LC —some other structure appears, but the lines are still present. 4/27/2020

100 90 80 PSLG-129 20 o C 15 o C 10 o C 70 60 50 40 30 20 10 0 0 2

Gels form faster at lower temperatures and lower M’s

sarah file: s.form 4 6 Weight % PSLG 8 30 25 20 15 10 5 0 10 Schmidtke

et al.

Figure 2a 9 10 11 12 13 Weight % PSLG at 15 o C PSLG-214 PSLG-28 14 sarah file: s.formmw

15 Schmidtke

et al.

Figure 2b 4/27/2020

4/27/2020 HO HO OH (H 3 CO) 3 Si NH 2 OH H 2 N O Si O O NH 2 Si O O O Si O Si O NH NH 2 2 RO O O H N O O NH NH NH NH R = Benzyl

4/27/2020 source: bf1xy2c 5.0

4.5

4.0

3.5

3.0

2.5

2.0

1.5

1.0

1.0

1.5

Silica Spheres C 18 H 37 R Composite Particles R h h = 990 = 973 2.0

2.5

q 2 /10 10 cm -2 3.0

R h = 1750 3.5

4.0

Figure 4 Fong and Russo

Core

Radius from DLS =

R c

Mass MW Number of particles / gram Surface area / particle Surface area / gram

PBLG Shell

Radius from DLS Thickness from DLS = t Volume Calculated mass assuming solid PBLG,  =1.26 g/mL Mass according to TGA Apparent PBLG weight % in solvated shell Expected shell thickness assuming effective number of initiators follows Eq. 9 970 Å 7.48 x 10 -15 g 4.50 x 10 +9 g/mol 1.33 x 10 +14 1.18 x 10 +7 Å 2 1.56 x 10 +21 Å 2 /g = 15.6 m 2 /g 1750 Å 780 Å (i.e., 1750 Å-970 Å) 1.86 x 10 -14 cm 3 2.35 x 10 -14 g 2.23 x 10 -15 g 9.5 % 11,500 Å

Hierarchical Structures Containing Composite Magnetic- Silica-Homopolypeptide Colloidal Particles

Research Progress Part A

Sibel Türkşen

Louisiana State University Department of Chemistry, Baton Rouge, 2001 4/27/2020

Outline

 Introduction    Purpose What has been done?

What we did?

Why?

  Background  Stöber spheres   Silica-homopolypeptide particles Magnetic inclusions   Results Conclusion 4/27/2020

Purpose

 Synthesize new composite core shell particles  Characterization  Investigate amorphous-crystalline, helix coil transitions  Applications  Biosensors   Artificial muscles Optical devices  4/27/2020 Separation and analysis of biomolecules

Previous Studies

    Colloid polymer interactions Stability of particles PS, PMMA, PEO attached to colloids Tsubokawa et al.  coated carbon black  Dietz et al.  fumed silica  Russo et al.

 colloidal silica 4/27/2020

This project

  Homopolypeptides as organophilic coatings Combining superparamagnetic ability with responsiveness  Using magnetic ability to make responsive chains  Crystalline colloids 4/27/2020

Generally...

 Most polymer colloids use boring, unstructured, random coil polymers 4/27/2020

Particle Preparation

Silica coating Surface Functionalization N N N N N N N NCA-monomer N N N N N N N N N N N N N N crosslinking N N N N N N N 4/27/2020

4/27/2020

N N N N N N N N N N N N N N

HELIX COIL

N N N N N N N N N N N N N N N N N N N N N N N N N N N N 4/27/2020

Superparamagnets

 Fluid properties of a liquid  Magnetic properties of a solid 4/27/2020

Synthesis of Magnetic Particles

2 FeCl 3 + FeCl 2 + 8 NH 4 OH -OH -OH -OH Fe 3 O 4 -OH -OH -OH + H 3 C CH 3 OH N CH 3 CH 3 TMA tetramethylammonium hydroxide 4/27/2020 Fe 3 O 4 + 8 NH 4 Cl N N + -OH N + OH OH N + + -OH Fe 3 O 4 OH N + OH N

Colloidal Silica

   Silica dispersion in liquid medium Monodispersed spheres Refractive index match with non-polar liquids   Effective coating Allow further coating 4/27/2020

Homopolypeptides

HN H C R O C n R = CH 2 CH 2 CO 2 CH 2 C 6 H 5 R = (CH 2 ) 4 NHCO 2 CH 2 C 6 H 5 for PBLG for PCBL  PBLG  best understood homopolypeptide   persistent structure helix-coil transition  PCBL  helix-coil transition @ 27  C in m-cresol 4/27/2020

Why homopolypeptides?

 Controllable and narrowly distributed size  High viscosity @ low conc.

 Well defined secondary structures  Responsiveness  Chiral nature 4/27/2020

SEM & FTIR Results for Stöbers

80 60 Stober spheres 40 20 0 4000 3500 3000 2500 2000 1500 1000 500 Wavenumber / cm -1 4/27/2020

TEM Results

Dark:Magnetic inclusions (~ 10nm) Gray:Glassy SiO 2 matrix 4/27/2020 Magnetic silica particles

DLS Results

0.30

0.25

0.20

0.15

0.10

0.05

4/27/2020 0.00

0 1 2 3 4 5 q 2 / 10 10 cm -1 Magnetic Silica Particles Magnetic Particles 0.064  Latex spheres 6 7 8

TGA Results

100 80 60 40 20 0 0 27.3 o C 100.0 % 150.05 o C 98.75 % 212.47 o C 2.5

296.77 o C 56.25 % 2.0

100 1.5

246.14 o C 1.009 % / o C 200 304.56 o C 0.6003 % / o C 300 395.58 o C Weight percentage 742.14 o C 12.32 % Derivative of weight percentage 400 500 Temperature ( o C ) 600 700 1.0

0.5

800 0.0

4.0

3.5

3.0

4/27/2020 Magnetic-silica-homopolypeptide composite particles

Colloidal crystal

4/27/2020 Silica-homopolypeptide composite colloidal crystal

    

Conclusion

First goal is achieved • Magnetic-silica-homopolypeptide composite particles Responsiveness • Promising results Well-defined Multiple applications Hierarchical particles 4/27/2020

   

Future Studies

Prove the responsive character of the particles Crosslinking via Grubbs’ catalyst Make the chains Investigate colloidal crystal structures 4/27/2020

Acknowledgment

    Paul Russo Our research group ACS Special thanks to…  Garrett   Cong Kem  Yilmaz, Selen & Murat...

4/27/2020

Stöber Synthesis

TEOS H 5 C 2 O OC 2 H 5 Si OC 2 H 5 OC 2 H 5 TEOS Hydrolysis C 2 H 5 OH NH 4 OH C 2 H NH 5 4 OH OH H O H O Si Si O O O Si O OH Si O OH H 5 C 2 O OC 2 H 5 Si O OC 2 H 5 OC 2 H 5 Si OC 2 H 5 OC 2 H 5 H O H O OH OH OH H O OH OH Stober Spheres 4/27/2020

Silylation Reaction

4/27/2020

4/27/2020 This was on my poster ,TEM of magnetic silica particles, I have more of these in the microscopy computer under users/sibel

4/27/2020 These are from the poster too.Since you have the video I think you won’t need them but in case