JCAPScanningDropletCellDataPackage.pdf

Dear colleagues,

This data package is being provided to contacts at

NREL, LBNL,

and

NIST

who have expressed interest in

developing

scanning drop

electrochemistry similar to that of the JCAP lab at Caltech. Enclosed

you

can

Machinist drawings

mag

to aid with

assembly instructions

Assembly and operation instructions

–

please

note that

these

were written for JCAP internal use

and

have not been updated in the past

2 years.

cently issued

patent

which was written several years ago and is somewhat out of date with

respect to the new design

Also

I am attaching

the Solid W

orks

version of the machinist drawings in item 1 (

“

SDC v1.1.SLDPRT

”

)

am happy to

help more broadly deploy this technology but would like to

remain informed of

who is

deploying it, so please do not distribute these materials beyond your respective research teams.

Best,

John Gregoire

25 May 2017

3.00

1.75

.875

1.875

2.70

.12

1.15

1.45

.15

.25

.50

.75

1.00

1.50

1.75

2.00

2.375

2.75

.06

1.250

.06

5X #2-56 (

.086)

.250

.096

.1875

.10

.15

.50

.06

2.00

.30

DO NOT SCALE DRAWING

SDC v1.1 Full

SHEET 1 OF 2

UNLESS OTHERWISE SPECIFIED:

SCALE: 1:1

WEIGHT:

REV

SIZE

NAME

DATE

COMMENTS:

Q.A.

MFG APPR.

ENG APPR.

CHECKED

DRAWN

FINISH

MATERIAL

INTERPRET GEOMETRIC

TOLERANCING PER:

DIMENSIONS ARE IN INCHES

TOLERANCES:

FRACTIONAL

ANGULAR: MACH

BEND

TWO PLACE DECIMAL

.01

THREE PLACE DECIMAL

.001

APPLICATION

USED ON

NEXT ASSY

PROPRIETARY AND CONFIDENTIAL

THE INFORMATION CONTAINED IN THIS

DRAWING IS THE SOLE PROPERTY OF

<INSERT COMPANY NAME HERE>. ANY

REPRODUCTION IN PART OR AS A WHOLE

WITHOUT THE WRITTEN PERMISSION OF

<INSERT COMPANY NAME HERE> IS

PROHIBITED.

PMMA

20.00°

30.00°

Followed by 3.0

Into/Out of Page

45.00°

.03

.06

1.445

.15

.242

.121

.262

.50

1.24

#4-40 (

.11)

.250

2X #4-40 (

.11)

.550

.25

1.00

.055

.093

10.00°

SECTION

A-A

Optical fiber

fiber path

supply

Bubble pump

KCl

Ref flush

tube

Figure 1. SDC cell with optical fiber close up

Supply tube

Bubble

pump

tube

Outer blue zip tube jacket

Inner white

jacket

Optical

fiber

Figure 2. Chopped fiber with

exposed inner white jacket and

exposed fiber. SMA 905 connector

stays on one end to connect to light

source (red circle).

Fiber outer

blue jacket

ThorLabs

VC1

clamp

Fiber inner

white jacket

Exposed optical fiber

Epoxy fiber to orange PEEK

Orange PEEK tube

Tygon

to connect orange to grey

Grey PEEK tube epoxied into cell

Figure 3. Zoom into fiber clamp from Figure 1.

document_title:

Scanning Droplet Cell Assembly

lead_author:

Dan Guevarra

additional_personnel:

Aniketa Shinde

document_version: 0.

document_format_version: 0.1

pertinent_experiments: eche

supporting_documents_description:

Figures are

attached

modified_date: 2015

document_

main_

content:

Scope and Purpose

1.1

This document describes the guidelines and recommended procedure for assembling the

scanning droplet cell

(SDC)

Responsibilities

2.1

Always check and test materials compatibility before

using new electrolytes or modifying

the design of SDC.

2.2

Keep a log of what electrolytes were used on a certain SDC. It is recommended to have

dedicated SDCs for acid, base, and ferri

ferrocyanide solutions.

Check MSDS for each

electrolyte

2.3

Record all change

s/updates in

log

Safety

3.1

Wear a standard lab coat, safety glasses, and clean nitrile gloves.

3.2

Use appropriate eye protection when dealing with UV and UV

containing light sources (385

nm UV, Xenon arc lamp).

3.3

Be mindful of the sharp glass tip on the refer

ence microelectrode capillary.

Required Tools

and Materials

4.1

2 mm allen wrench

4.2

2.5 mm allen wrench

4.3

2/56 inch allen wrench

4.4

0.050 inch allen wrench

4.5

1/16 inch O.D. PEEK tubing, 0.020 inch I.D.

(orange)

4.6

1/16 inch O.D. PEEK tubing, 0.030 inch I.D.

(green)

4.7

1/16 inch O.D. PEEK tubing, 0.040 inch I.D.

(beige)

4.8

1/16 inch tube cutter

4.9

platinum electrode (30 gauge Pt wire)

4.10

Ag/AgCl electrode (in

house preparation)

4.11

24 gauge copper wire, stranded (red jacket)

4.12

24 gauge copper wire, stranded (white jacket)

4.13

Wire cutter /

stripper

4.14

Soldering iron

4.15

Tin/lead solder

4.16

1/8” heat shrink

4.17

Heat gun

4.18

1.0mm borosilicate or alumin

silicate pipette with ~50 um tip

4.19

SDC

main block

4.20

SDC reference electrode carriage and slide

4.21

polypropylene set screws, bored out

4.22

Teflon compression tee with

1/16” ports

4.23

0.43 mm O.D. PEEK

coated fused silica capillary tubing

4.24

Hardman “Double

Bubble” Epoxy red label, quick dry, zero volume change

4.25

Optical fiber scoring tool

4.26

Fine

tip straight tweezers

4.27

Siphon assembly gaskets

4.28

Socket cap screw size used with 2 mm

allen wrench?

4.29

Ocean Optics P400

Vis, Connector SMA 905 (400 micron fiber core diameter), 1

meter (depending on instrument set up), zip tube jacket

4.30

ThorLabs small V clamp VC1

Solution Ports

5.1

Cut ~3/4 inch lengths of the 1/16 inch O.D. PEEK tubing t

o port the top solution channels on

the SDC main block. Green or beige tubing sizes may be used.

Green tubing has a smaller

inner diameter but does not excessively restrict the flow rate. For high

flow applications,

use beige.

5.2

Cut

1/4

inch length of tubin

g green or beige

for the lower port (which supplies the droplet)

The tube should clear the square nub at the lowest part of the SDC main block, but not poke

into the junction of slanted and vertical channels.

5.3

Leave the slanted channel open until the count

er electrode is prepared.

Siphon Tube

6.1

Cut

three

inch lengths of fused silica capillary tubing using the optical fiber scoring tool.

Make sure the score and break are clean. Trim back shattered tips.

6.2

Cut

three

~1/2 in

ch lengths of orange PEEK tubing a

nd epoxy the O.D. of the fused silica

capillary to the I.D. of the orange PEEK.

The capillary should be flush with the PEEK tubing on

one side, avoid having any small portion of the capillary sticking out of the flush side.

6.3

After the epoxy has dried, inser

t the capillary side of the siphon assembly through a bored

out polypropylene set screw. The set screw should stop at the PEEK tubing.

6.4

Use fine

tipped straight tweezers to pry open a siphon assembly gasket and insert the

screw

loaded capillary side through

the gasket. Repeat and load 2 gaskets per siphon tube.

6.5

Insert the

gasketed siphon tube into the SDC main body. Adjust the siphon lengths such that

the side tips end at the center

line of the supply tube diameter, and the center tip ends 1

mm away from the

supply tube. Secure in place by tightening the set screw.

Counter Electrode

7.1

Cut a

2.5

inch length of platinum

electrode

wire and ~12 inches of 24 gauge copper wire

with red jacketing.

7.2

Strip 0.25 to 0.5 inches of jacketing

off the copper wire and twis

t around a short length of

the platinum electrode. Minimize wire fraying, apply light solder, and avoid excess beading.

Try to fit the soldered portion inside the I.D. of beige PEEK tubing.

7.3

Cut

~1/2 inch length of

beige

PEEK tubing.

Adjust the length of PE

EK tubing such that the

platinum electrode wire inserted through the slanted channel does not extend into the

central vertical channel.

7.4

Epoxy the wire

to the PEEK tubing making sure to fully seal the inner diameter.

7.5

Use heat shrink over the wire and some

of the PEEK tubing to enhance mechanical support.

7.6

Insert the prepared platinum counter electrode into the slanted channel of the main body

and epoxy in place. The beige tubing or stiff portion on the wire side should not extend past

the top of the main

ock

Reference Electrode Tee and Alignment

8.1

The Teflon tee with compression fittings should only be used with 1/16 inch tubing. Do not

use Teflon tape to adapt 1.0 mm or 1.5 mm tubing. Do not use epoxy on this part.

8.2

Cut ~1/4 inch length of beige PEEK tub

ing to serve as an adaptor f

or the 1.0 mm pipette

capillary and insert into one of the side ports of the Teflon tee.

8.3

Cut ~1/2 inch length of green PEEK tubing and insert into the center port of the Teflon tee.

8.4

The Ag/AgCl electrode wire should already be f

astened to PEEK tubing as part of the

electrode preparation. Do not trim the Ag/AgCl electrode length, which would expose silver

metal at the core.

8.5

Cut ~12 inches of 24 gauge copper wire with white jacketing.

8.6

Strip from the copper wire a length equal to t

he exposed silver lead of the

prepared Ag/AgCl

electrode. Twist the copper wire around the silver lead and solder.

8.7

Cover the exposed solder joint and some of the PEEK tubing with heat shrink. Keep in mind

that the heat shrink portion of the PEEK tubing wil

l not fit into the Teflon tee.

8.8

Insert the prepared Ag/AgCl electrode into the remaining open port of the Teflon tee and

through the beige PEEK.

8.9

Position the 1.0 mm pipette capillary parallel with the wire direction, with the pipette tip

(start of taper) 0.

5 mm past the end of the Ag/AgCl electrode. Score the glass capillary ~1.0

mm into beige PEEK. This ~1.0 mm length will be inserted into the beige PEEK.

Cleanly break

the scored capillary. If the break is not clean, sand down the cracked portions using opt

ical

fiber polishing paper.

8.10

Remove the beige PEEK tubing from the Teflon tee and widen the capillary side opening

using a round conical file or similar tool with a tapered tip.

8.11

Fit the glass capillary (non

tapered end) into widened PEEK tubing and apply ep

oxy

around the union. Try to keep the glass capillary and PEEK tubing collinear as the epoxy

dries.

8.12

Slowly i

nsert the glass capillary PEEK

first into the Teflon tee. The beige PEEK and glass

capillary will fit over the Ag/AgCl electrode. Take care not to

cratch off the AgCl coating

upon insertion. Be aware of the Ag/AgCl electrode tip and keep 0.5 mm spacing between

the electrode tip and the start of the capillary taper. The glass taper is extremely fragile and

can breach if the electrode tip presses again

st it from the inside.

8.13

Use a 2.0 mm allen wrench to attach the assembled tee to the stainless steel carriage

(looks like a C

clamp with a set screw fastener). The orientation of the carriage does depend

on the mounting points of the stainless steel slide.

8.14

Attach the stainless steel slide to the main block using socket cap screws and the 2.0

mm allen wrench. The angle of the slide should point toward the supply tube.

The slide can

be disassembled and mounted on the opposite face if the carriage mount needs t

o face a

particular side of the cell. The reference electrode tee’s central port must be accessible for

connecting the reference flush solution tubing.

8.15

The slide’s carriage mount contains a small magnet. Carefully position the reference

electrode tee and s

tainless steel carriage over the mounting point, but do not immediately

drop the carriage over the magnet. The three alignment pins on the mount should match

with the two divots and trough on back of the carriage.

8.16

Do not allow the reference capillary tip

to contact the lower supply tube on the main

body. If the capillary tip is in danger of hitting, adjust the

slide position using a 0.050 inch

allen wrench (this screw counters the pull of the extended spring). The alignment pins can

also be adjusted with a

2/56 inch allen wrench to affect the angle of the capillary tip.

Position the capillary tip to span the supply tube opening, terminating at the opposite inner

diameter. The lowest point of the capillary tip should be no more than 0.5 mm below the

supply t

ube.

Cell Mounting

9.1

Attach the finished cell to the SDC mounting arm using socket cap screws and a 2.0 mm

allen wrench. Only 2 screws are necessary.

9.2

Attach the mounting arm and cell to the z

micrometer slide using ¼

20 socket cap screws

and and a 3/16 i

nch allen wrench. The mounting arm

has a cross hole pattern. Use the left

and right holes for mounting. The top hole should be reserved for a fiber optic support

mount

(see Section 10).

9.3

The upper solution ports may have multiple configurations. For dark

catalyst screening, it is

recommended to connect the differential pump to the port closest to the counter

electrode

entry point and solution delivery to the straight

through vertical channel above the supply.

For photocurrent screening, a fiber optic needs

to come down the straight

through channel

and terminate at the supply tube. A differential pump can be used in the fiber optic setup

with slight modification of the main block

: one of the screw mounting points on the

reference tee side of the cell must be

drilled through to the legacy horizontal channel to

accommodate an additional solution port.

10.

Preparing and inserting fiber optic for front

side illumination

10.1

Determine length of fiber needed to connect from light source (Connector SMA 905

port)

to the end of supply tube on cell.

Using a small blade, cut through the blue jacket

only and r

emove outer blue zip tube jacket

. Do the same with

inner white hard tubing

such that a porti

on of fiber is exposed (figure 2

Remove connector and trim fiber to

length needed using the optical fiber scoring tool and polishing papers.

10.2

The exposed

portion of the fiber will travel through the center port in the cell and will

be supported by the ThorLabs clamp. The clamp will hold the blue jacket or white hard

be portion of the fiber in place (figure

)

10.3

Using a small length (1

2 cm) of orange PEEK tubing, epoxy fiber to tube. Use a small

piece of tygon tubing to connect orange tube to grey tube in cell (figure

). This prevents

having to epoxy the fiber to

the cell directly and allows more flexibility in

removing/changing fibers.

The tygon is connecting the fiber to the cell.

10.4

While setting up the path of the fiber and location of light source, keep the bend radius

limit in mind (each fiber has a lower limit for bend radius).