BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//ZContent.net//ZapCalLib 1.0//EN
CALSCALE:GREGORIAN
METHOD:PUBLISH
BEGIN:VEVENT
SUMMARY:Beyond Bright Field Imaging: Optical Phase as a Quantitative Finger
 print Across Material Systems
LOCATION:Chemistry A101
TZID:America/Denver
DTSTART:20260424T160000
UID:2026-06-05-13-00-32@natsci.colostate.edu
DTSTAMP:20260605T130032
Description:Existing electroanalytical techniques used to measure the state
  of charge of battery electrodes are a mere approximation. Conventional me
 thods assume a one-to-one correspondence between electrons transferred and
  guest ions inserted into the host cathode material. Competing electrochem
 ical processes which consume electrons — solid electrolyte interface for
 mation\, parasitic redox reactions\, lithium plating\, etc. — bypass the
  intended ion insertion. This systematic violation negates the one-to-one 
 assumption leading to progressively inaccurate state of charge measurement
 s. Through extraction of the complex polarizability of individual nano-par
 ticles and thin films Quantitative Scattering Microscopy (QSCAT)\, a diffe
 rential phase contrast-based optical microscopy technique\, enables quanti
 fication of guest ions within a cathode host independent of electron trans
 fer. Relative guest-ion concentrations in a host lattice proportionally al
 ter the refractive index which encodes an optical phase shift (∆𝜙) in
  the backscattered light. QSCAT provides a non-destructive\, label-free\, 
 and electro-chemically independent readout\, stemming from a direct propor
 tionality relating ∆𝜙 to the spatial distribution of Re(𝛼) and Im(
 𝛼). Acts one and two introduce\, apply\, and validate the optical frame
 work enabling quantitative extraction of ∆𝜙 through determination of 
 the physical height of chromium features on a USAF 1951 resolution test ta
 rget with 98.7% agreement against atomic force microscopy. Act three demon
 strates the deployment of QSCAT\, including current sensitivity limitation
 s and the way forward\, towards optical de-termination of gold nanoparticl
 es solely from the extracted complex polarizabilities. Act four details th
 e quantitative characterization of two host-guest model systems — Nile R
 ed-loaded polystyrene beads and Er-doped NaYF4 nanocrystals) through gold-
 standard analytical techniques establishing ground truth to benchmark proj
 ected QSCAT performance. Together these results establish QSCAT as a quant
 itative optical platform for guest-host materials characterization\, with 
 a path towards operando single-particle imaging in electrochemical energy 
 storage systems where the electroanalytical assumption breaks down. 4:00 p
 m
END:VEVENT
END:VCALENDAR